Mosquito ShieldTM, a transfluthrin passive emanator, protects against pyrethroid-resistant Anopheles gambiae s.l in central Benin

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Mosquito Shield TM is a transfluthrin passive emanator undergoing evaluation for malaria control. Studies evaluating its entomological impact against different local malaria vector populations would help guide its deployment in endemic countries. Methods: We performed a two-arm single-blinded small-scale household randomised entomological trial to assess the impact of Mosquito Shield TM on the human landing rate of wild pyrethroid-resistant Anopheles gambiae sl vector mosquitoes in houses in the Ganhoua village of the Zakpota District of central Benin. From a total of 30 houses, 15 were randomly allocated to receive Mosquito Shield TM while the remainder received a placebo product. The trial lasted through the life of the Mosquito Shield TM product (32 days). Mosquito sampling was performed by human landing catches at baseline and at 6 timepoints post-intervention (days 0-1, 7-8, 14-15, 21-22, 28-29 and 31-32). Collections were performed for 2 days at each sampling time point. WHO cylinder bioassays were conducted during the trial with F1, An gambiae sl mosquitoes that emerged from larvae from the study area to assess the intensity of resistance to pyrethroids in the wild vector population. Findings: The vector population in the study area showed a high intensity of resistance to pyrethroids. Baseline An gambiae sl human landing rates were similar in houses in both study arms before product application (11.53/person/night vs 11.67/person/night, p>0.05). A total of 5736 mosquitoes were collected in the placebo control arm and 3862 in the Mosquito Shield TM arm post-intervention. Overall An gambiae sl human landing rates post-intervention were significantly lower in houses in the Mosquito Shield TM arm 18.13/person/night) compared to the houses in the placebo control arm (26.84/person/night, IRR=0.658, p<0.001). Over the lifespan of the product, Mosquito Shield TM provided a significant protective efficacy of 34.2% (22.1%-44.4%, p<0.001) against wild pyrethroid-resistant An gambiae s.l. vectors compared to the placebo. Human landing rates of other nuisance vector mosquito species ( Culex and Mansonia ) were also reduced in houses treated with Mosquito Shield TM compared to the placebo. Conclusion : Mosquito Shield TM , a transfluthrin passive emanator, provided significant protection against pyrethroid-resistant malaria vectors to households in Benin. The spatial repellent shows potential to reduce malaria transmission by pyrethroid-resistant An gambiae sl vector mosquitoes and cover gaps in malaria control when deployed to complement existing vector control interventions. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Vector control through the large-scale deployment of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) contributed substantially to the remarkable reductions in malaria burden between 2000 and 2015 [ 1 ]. Global progress against malaria has unfortunately stalled in recent years and is expected to go further off course if no additional measures are implemented [ 2 ]. This stalled progress has been attributed to several factors including the development of vector resistance to the insecticides used on ITNs and IRS, poor access and durability of ITNs and reduced funding for malaria control. This highlights the need to both strengthen the impact of existing tools and bring to market new cost-effective vector control interventions to fill gaps in protection and facilitate advancements towards global malaria elimination targets. Spatial repellents are airborne repellent compounds that alter mosquito behaviours inducing movement away from a chemical stimulus and interfering with host detection and feeding. By disrupting the mosquito’s host-seeking behaviour when volatilised into the air within a given area, they reduce human vector contact and thus provide personal and household protection potentially reducing disease transmission [ 3 – 5 ]. Commercial spatial repellent products such as mosquito coils, and electrical plug-ins are widely available for protection from mosquito bites however, they require a heat source to volatize the active ingredient and disperse adequate concentrations into the target area resulting in poor user compliance and health risks associated with the smoke generated by burning [ 6 – 8 ]. Passive emanator spatial repellents were developed to provide a volatile concentration of the repellent active ingredient at room temperature from a point source using only natural airflow thus requiring little to no compliance from the user [ 9 ]. Their efficacy against Aedes mosquito vectors of diseases such as dengue, chikungunya and Zika has been demonstrated in multiple studies [ 9 , 10 ]. Mosquito Shield™, a transfluthrin passive emanator developed by SC Johnson & Son Inc, is a spatial repellent product designed to be easy to use with minimal handling, which may help to increase user compliance and acceptability. It can be hung in semi-enclosed and enclosed spaces to continuously protect against bites from mosquitoes. The emanator consists of a multilayer plastic film pre-treated with 110 mg of transfluthrin which passively emanates using natural airflow to protect people from mosquitoes in a specific area. Previous studies in Peru demonstrated the potential of an earlier prototype of Mosquito Shield™ to provide substantial reductions in human-vector contact and Aedes-borne viral disease transmission [ 11 ]. A cluster randomised controlled trial (RCT) in Indonesia showed a 60% protective efficacy against malaria infection in moderate to high-risk clusters that received the product [ 12 ]. Further RCTs to determine the public health value of Mosquito Shield™ as part of the required evidence for the endorsement of the intervention by the World Health Organisation (WHO) for malaria control, are ongoing in Kenya [ 13 ] and Mali [ 14 ]. In addition to RCTs, small-scale entomological studies investigating the impact of spatial repellent passive emanators against local malaria vectors may help guide their deployment. Several semi-field entomological trials conducted in East Africa have demonstrated the capacity of transfluthrin-based spatial repellent products including Mosquito Shield™ to protect humans from malaria mosquito bites [ 15 – 17 ]. There is however little to no evidence of their entomological performance in West Africa where local vectors have historically exhibited higher levels of pyrethroid resistance [ 18 ]. We performed a small-scale household randomised trial to assess the entomological efficacy of Mosquito Shield™ in households in the Zakpota District of central Benin where the local vector population shows a high intensity of resistance to pyrethroids. Thirty households recruited from the study area were randomised to receive Mosquito Shield™ or a placebo product and performance was assessed in terms of the reduction in landing rates of wild vector mosquitoes on humans in Mosquito Shield™ treated households compared to the placebo-treated households. Materials and methods Study area The study was performed in the Ganhoua village situated in the Za-Kpota District (7.2384° N, 2.2040° E) of the Zou Department of Benin. Results from a recent entomological survey conducted in the Za-Kpota District showed that the main vector, An. gambiae sl , consisting of ~ 45% An. colluzi and ~ 55% An . gambiae ss and is highly resistant to pyrethroids with high levels of kdr (> 80%) and overexpressed P450 enzymes [ 19 ]. Study design and sample size considerations This was a two-armed single-blinded small-scale household randomised entomological trial with houses as units of observation. The evaluation was performed in a total of 30 houses; 15 were randomly allocated to receive the Mosquito Shield™ product and the remainder received a placebo that was similar to the product but did not contain the active ingredient. Based on human landing rates of the main malaria vector per house per night observed in a previous study in the study area, with a total of 12 collection nights in each house through the life of the product, the study design had > 80% power to detect a 25% reduction in human landing rates with Mosquito Shield™. After the recruitment of households, a baseline survey was conducted to assess household characteristics, mosquito species composition and human landing rates in each house. Treatments were then applied, and houses were assessed for the impact of the product on human landing rates of the major malaria vector at specific time points throughout the life of the product. Householders and mosquito collectors were blinded to the intervention applied in each house. Recruitment and allocation of participating households Approximately forty-five (45) households were initially recruited at baseline. Houses were recruited within a 2.5 km transect of the village and were within 10–15 minutes walking distance from each other. Households with pregnant and/or nursing mothers were excluded. The study details and frequency of sampling were explained to householders by the study team in their local language with support from community health workers. Following recruitment, a baseline survey was conducted to collect data on the construction characteristics, presence of ITNs and frequency of use of vector control products in each household. To help guide the deployment of the product, measurements were taken of each room in the recruited household. Baseline entomological indices for malaria vectors including species composition and human landing rates, were collected via human landing catches (HLC). Out of the 45 households recruited at baseline, thirty (30) were included in the evaluation (Fig. 1 ). Houses showing very low vector mosquito landing rates and high use of consumer vector control products (coils, sprays, repellents etc) at baseline were excluded. Households included in the evaluation also agreed to not use consumer vector control products during the study. Selected households were then randomly allocated to each study arm based on baseline An gambiae sl human landing rates. Randomisation was performed multiple times to ensure that both study arms were similar in terms of An gambiae sl human landing rates at baseline. Installation of Mosquito Shield ™ products All rooms in study houses were between 9m 2 and 18m 2 in size thus requiring 4 Mosquito Shield™ products per room per house (1 per wall) as indicated by the manufacturer’s instructions. Installation was done by the study team in each study house. Products were fixed on walls using nails and small pieces of wood and were placed at approximately two-thirds of the wall height from the ground (Fig. 2 ). Placebo products were installed using the same method. A total of 140 Mosquito Shield™ and 132 placebo products were installed in the houses included in the study. Mosquito sampling and processing The trial was performed from April to May 2022 and lasted for the duration of the efficacy of the Mosquito Shield™ product (32 days). Mosquitoes were sampled in recruited houses once at baseline and 6 times within the life of the product (0–1, 7–8, 14–15, 21–22, 28–29, 31–32 days) post-treatment application, using HLC. Sampling was done for 2 consecutive nights at each round of sampling in one dedicated room in each house. Consenting human volunteer mosquito collectors working in pairs collected mosquitoes landing on their legs overnight from 7 pm to 7 am in each house on each sampling day. Collections were done in two shifts each night (7 pm to 1 am and 1 am to 7 am). The collectors sat on chairs with their lower limbs exposed and collected all mosquitoes which landed on them using sucking tubes. To characterize Anopheles biting time behaviour, collections were recorded per hour. To control human attractiveness to mosquitoes, for each collection round, human collector pairs were rotated between houses in the intervention arm and the placebo arm on successive nights. In the morning, all collected mosquitoes were transported to the laboratory for morphological identification to species level using appropriate taxonomic keys. The date of collection, house identification number and species were recorded for each mosquito. The key outcome measure used to determine the efficacy of Mosquito Shield™ in the study houses was the protective efficacy defined as the percentage reduction in human landing rates of malaria vector mosquitoes collected by HLC in households in the treated arm compared to the placebo arm. Data analysis Differences in the numbers of female An gambiae sl landing per person per household were analysed using mixed effects negative binomial regression in STATA version 17 with treatments and collection timepoint added as fixed effects and households as random effects. Vector incidence rate ratios (IRR) between the Mosquito Shield™ and placebo arms and 95% confidence intervals were calculated for the entire duration of the study and for each sampling timepoint. Overall efficacy was expressed in terms of the protective efficacy (PE) against mosquito landing rates in the Mosquito Shield™ arm relative to the control placebo arm which was calculated as follows: $$PE=(1-IRR)\times 100$$ where IRR is the incidence rate ratio in the Mosquito Shield™ group compared to the placebo group. Ethical considerations The study received ethical approval from the ethics review committee of the Ministry of Health in Benin (CNERS, No. 54). Informed consent was obtained from the head of each participating household and mosquito collectors before they participated in the study (Appendix 3). The consent forms and participant information sheets were explained to them in their local language. An impartial witness was used when participants could not read or write. Mosquito collectors were offered chemoprophylaxis during the study. A study nurse was available to examine any cases of fever and any collectors found positive for malaria, were treated free of charge during the study and up to 4 weeks after the end of the study. Participants were free to withdraw from the study at any time. Susceptibility tests To determine the frequency of insecticide resistance in the wild vector population of the study area during the trial, WHO cylinder bioassays were performed on 2 to 5 days old adult F1 female mosquitoes emerging from larvae collected from breeding sites around the study houses. Approximately 100 female mosquitoes per insecticide were exposed for 1 h in batches of 25 to alpha-cypermethrin 0.05% and permethrin 0.75% and to filter papers treated at the 1x, 5x and 10x the diagnostic doses of these insecticides. Knockdown was recorded after 1 h and mortality after a 24 h holding period. Results Baseline characteristics of participating households The average number of inhabitants per household among the 30 households included in the study was 2 and this was similar between households in both study arms (Table 1 ). All households owned at least one LLIN. The proportion of people who reported sleeping under nets every night was 80%. Most nets were PermaNet® 2.0 (13/30) and Yorkool® (14/30). Overall, most houses were made of either cement or a mixture of mud and cement (27/30) and had closed eaves. Two households reported using consumer vector control products on some nights. An. gambiae sl was the most abundant mosquito species in the study houses at baseline and represented 73% of the collection. Other species collected in lower densities were Mansonia africana (18%) and Culex quinquefasciatus (8%). Table 1 Household characteristics Placebo Mosquito Shield™ Total Indicators N N N (%) Total N of households 15 15 30 - Total N of people 51 40 91 - Number of rooms for sleeping 26 20 46 - Mean number of persons per house 2 2 2 Type of housing Mud 3 4 7 23.33 Cement 8 5 13 43.33 Mud + Cement 4 6 10 33.33 LLINs PermaNet 2.0 5 8 13 43.33 Yorkool 8 6 14 46.66 Other LLINs 1 2 3 10 Use of LLINs Every night (7 nights) 12 12 24 80 Use of consumer vector control products Every night (7 nights) 0 0 0 0 Most nights (5–6) 0 0 0 0 Some night (1–4 nights) 1 1 2 6.66 Not used last week 1 1 2 6.66 Species composition and overall mosquito landing rates post-intervention A total of 5,736 female mosquitoes were collected in the placebo arm and 3,862 female mosquitoes in the Mosquito Shield™ arm post-intervention giving an overall reduction in mosquito landing rates of 32.67% (Table 2 ). The largest proportion of mosquito species collected were Anopheles gambiae sl followed by Culex spp and Mansonia spp . Small numbers of secondary malaria vectors ( An pharoensis and An ziemani ) were also collected. Species composition in terms of the proportion of each species, was generally similar across both study arms. Overall, for each mosquito genera, lower numbers were collected in houses in the Mosquito Shield™ arm compared to the placebo arm (Table 2 ) and these differences were significant for Anopheles , Culex and Mansonia mosquitoes (26.57% − 35.20%, p < 0.05). Reductions in Aedes aegypti were observed though the numbers collected were too few (13). Table 2 Total numbers and species composition of mosquitoes collected by HLC per study arm Species Placebo Mosquito Shield Reduction in numbers collected (%) N % N % Anopheles gambiae s.l. 4831 84.22 3263 84.49 32.46 Anopheles pharoensis 93 1.62 49 1.27 47.31 Anopheles ziemani 12 0.21 1 0.03 91.67 Aedes aegypti 13 0.23 2 0.05 84.62 Culex species 358 6.24 232 6.01 35.20 Mansonia species 429 7.48 315 8.16 26.57 Total 5736 100 3862 100 32.67 Reduction in human landing rates of An. gambiae sl The An gambiae sl landing rates in both study arms at each time point and reductions observed with Mosquito Shield™ relative to the placebo control arm are shown in Table 3 and Fig. 2 . Landing rates were lower at baseline compared to post-intervention time points and this can be attributed to local changes in vector density over time. Landing rates were generally lower in houses in the Mosquito Shield™ arm compared to the placebo control arm at all 6 post-intervention sampling timepoints and these differences were significant at most time points (P < 0.05). Overall, mosquito landing was significantly lower in houses with Mosquito Shield™ (18.13 bites per person per night) compared to the placebo control (26.84 bites per person per night, IRR = 0.658, P < 0.001). The protective efficacy of Mosquito Shield™ was lowest in the first round of collection (9.1% at 0–1-day, p = 0.335) but increased in the subsequent time points and ranged from 18.1–59%. This was probably due to the product taking some time to build up the volatile AI in the treated houses. Mosquito Shield™ provided a significant overall protective efficacy of 34.2% (22.1%-44.4%, p < 0.001) post-intervention. Hourly biting rates of An. gambiae sl were also consistently higher in the placebo control arm compared to the Mosquito Shield™ arm at all times of the night (Fig. 3 ). A larger reduction in mosquito biting was observed in the early morning hours (4:00 am to 7:00 am) with Mosquito Shield™ compared to the placebo. Table 3 Human landing rates and protective efficacy of Mosquito Shield™ against wild An gambiae sl in households in Ganhoua village, Zakpota sub-district, Benin Time point Arm Total collected Person nights HBR IRR (95% CI) % Protective efficacy (95% CI) p value Baseline Placebo 346 30 11.53 1.012 (0.834–1.226) n/a 0.907 Mosquito Shield 350 30 11.67 0–1 days Placebo 879 30 29.30 0.909 (0.749–1.104) 9.1 (0-25.1) 0.335 Mosquito Shield 799 30 26.63 7–8 days Placebo 1007 30 33.57 0.410 (0.309–0.544) 59 (45.6–69.1) < 0.001 Mosquito Shield 428 30 14.27 14–15 days Placebo 719 30 23.97 0.819 (0.535–1.255) 18.1 (0-46.5) 0.359 Mosquito Shield 589 30 19.63 21–22 days Placebo 676 30 22.53 0.779 (0.654–0.927) 22.1 (7.3–54.8) 0.005 Mosquito Shield 535 30 17.83 29–30 days Placebo 822 30 27.40 0.540 (0.452–0.644) 46 (35.6–54.8) < 0.001 Mosquito Shield 450 30 15.00 31–32 days Placebo 728 30 24.27 0.599 (0.463–0.774) 40.1 (22.6–53.7) < 0.001 Mosquito Shield 462 30 15.40 Total (post intervention) Placebo 4831 180 26.84 0.658 (0.556–0.779) 34.2 (22.1–44.4) < 0.001 Mosquito Shield 3263 180 18.13 Susceptibility test results Mortality rates of the susceptible laboratory-maintained An gambiae ss Kisumu strain after exposure to permethrin and alpha-cypermethrin treated papers in WHO cylinder bioassays were both 100%. With the wild An gambiae sl from the study area (Ganhoua), mortality rates were 37% at 1X, 80% at 5x and 75% for permethrin and 25% at 1x, 78% at 5X and 77% at 10X for alpha-cypermethrin (Fig. 5 ) showing that the wild strain had a high intensity of resistance to both pyrethroid insecticides. Discussion The purpose of this study was to evaluate the impact of Mosquito Shield™, a transfluthrin passive emanator on human landing rates of wild free-flying high-intensity pyrethroid-resistant Anopheles gambiae sl in houses in the Ganhoua village in the Zakpota district of central Benin. The data showed a significant protective effect of 34.2% against malaria mosquitoes in Mosquito Shield™ treated houses relative to houses treated with a placebo. The intervention remained efficacious through its 1-month product span. The findings demonstrate the impact of a transfluthrin passive emanator against local malaria vectors in Benin for the first time and corroborate multiple studies that have shown the potential of spatial repellents to protect humans from vector mosquitoes in other countries [ 15 , 17 , 20 ]. The levels of protective efficacy achieved with Mosquito Shield™ in this study (34.2%) were nevertheless lower than what was observed against An arabiensis (70% protective efficacy) in a recent experimental hut trial in Tanzania, East Africa [ 17 ]. The difference in outcome between both studies could be attributed to higher intensities of pyrethroid resistance in the An gambiae sl population in the Benin study and/or to inherent differences in vector species. The An gambiae sl vector population in Benin is highly anthropophagic, feeding almost entirely on humans indoors [ 21 ], while An arabiensis tends to be more zoophilic and is less attracted to humans compared to An gambiae sl [ 22 , 23 ]. Susceptibility bioassays showed that the Benin vector population had a high intensity of resistance to pyrethroids with mosquito mortality remaining below 80% even at doses 10 times the diagnostic dose of permethrin and alpha-cypermethrin. This high intensity of resistance to the pyrethroids coupled with the higher local vector attractiveness to humans may therefore have reduced the capacity of the transfluthrin passive emanator to sufficiently modify the mosquitoes’ host-seeking behaviour in the Benin study and induce greater levels of protection. While it is unclear how reductions in mosquito landing rates will impact malaria incidence and prevalence, traditional malaria transmission models indicate that reducing human landing rates and thus human vector contact even at the levels demonstrated in this study can have major effects on the vectorial capacity of a vector population [ 24 ]. Our findings therefore show the potential of the Mosquito Shield™ spatial repellent device to reduce malaria transmission by pyrethroid-resistant An gambiae sl vector mosquitoes to individuals in treated households with high ITN use in a West African setting where vectors historically exhibit high intensities of pyrethroid resistance [ 18 ]. Results from the ongoing RCT of Mosquito Shield™ in Mali [ 14 ] may further elucidate the epidemiological impact of the intervention on clinical malaria when applied at a community scale in the region. The Mosquito Shield™ product was designed to last approximately 1 month, and, in this study, we demonstrated its efficacy for this period. However, mosquito transmission seasons in endemic countries typically last several months hence it is expected that under operational conditions, the Mosquito Shield™ product will have to be replaced multiple times in houses to cover the entire transmission season. While installation was relatively easy for the study team, requiring less than 15 minutes per house, the process can be very demanding for householders if it must be done too frequently. To overcome this challenge, an advanced longer-lasting version of the transfluthrin passive emanators has been developed by the manufacturer and is undergoing evaluation in semi-field studies across Africa. Mosquito Shield™ induced substantial reductions in human landing rates of Culex and Mansonia (26–35%) mosquitoes, vectors of human filariasis, in treated houses compared to the placebo. Reductions in densities of such nuisance mosquitoes have been reported in multiple small-scale trials of transfluthrin spatial repellents [ 16 , 25 ]. Protection from nuisance mosquitoes is usually associated with an increased uptake of malaria vector control interventions. This finding may therefore have positive implications for the acceptability of Mosquito Shield™ to householders. Further studies investigating user acceptance at both household and community levels are advisable. This study evaluated the entomological impact of transfluthrin passive emanators in households which had pyrethroid-only nets in them. Following WHO’s recent endorsement of dual active ingredient nets, [ 26 ], many endemic countries are replacing pyrethroid-only nets with these new more effective nets. Passive emanators will therefore likely be deployed against a background of high coverage with dual AI nets. Studies investigating their potential to complement dual AI nets may help guide local deployment strategies. Conclusion Our study demonstrated a 34.2% protective efficacy of Mosquito Shield™, a transfluthrin passive emanator, against a high-intensity wild pyrethroid-resistant malaria vector population when applied in houses in Benin. Mosquito Shield™ remained protective throughout its product life of 30 days. The passive emanator shows potential to improve the control of malaria transmitted by pyrethroid-resistant An gambiae sl vector mosquitoes and to help cover gaps in malaria control that may exist with core vector control tools. Abbreviations ITN: Insecticide treated nets IRS: Indoor residual spraying WHO: World Health Organization AI: Active ingredient HLC: Human landing catches HBR: Human biting rate IIR: Incidence Rate Ratio RCT: Randomised controlled trials CREC: Centre de Recherche Entomologique de Cotonou LSHTM: London School of Hygiene & Tropical Medicine PAMVERC: Pan African Malaria Vector Research Consortium AIRID: African Institute for Research in Infectious Diseases Declarations Availability of data and material The datasets used and/or analysed during the current study are available from the corresponding authors on reasonable request. Competing interests The authors declare that they have no competing interests. Consent for publication Not applicable Funding This project is supported by a grant to Corine Ngufor from SC Johnson & Son Inc. The funders have no role in study design, data collection and analysis and the decision to publish this manuscript. Authors’ contributions CN designed the study and supervised its implementation. AF, JA ES and RO performed the entomological surveys and susceptibility bioassays with support from BN. CH was responsible for data management and processing. CN, RG and AF analysed the data and prepared the manuscript tables and figures. CN wrote the manuscript text with support from AF. All authors read and approved the final manuscript. Acknowledgements We thank Dr. Thomas Mascari and Ms Madeleine Chura of SC Johnson & Son Inc for providing the test items and for their support. We appreciate the study participants and community leaders of Ganhoua village of the Za-Kpota District for their participation, support and collaboration. 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Ngufor C, Govoetchan R, Fongnikin A, Hueha C, Ahoga J, Syme T, Agbevo A, Daleb A, Small G, Nimmo D, et al: Community evaluation of VECTRON™ T500, a broflanilide insecticide, for indoor residual spraying for malaria vector control in central Benin; a two arm non-inferiority cluster randomised trial. Sci Rep 2023, 13: 17852. Devine GJ, Vazquez-Prokopec GM, Bibiano-Marín W, Pavia-Ruz N, Che-Mendoza A, Medina-Barreiro A, Villegas J, Gonzalez-Olvera G, Dunbar MW, Ong O, et al: The entomological impact of passive metofluthrin emanators against indoor Aedes aegypti: A randomized field trial. PLoS Negl Trop Dis 2021, 15: e0009036. Akogbéto MC, Salako AS, Dagnon F, Aïkpon R, Kouletio M, Sovi A, Sezonlin M: Blood feeding behaviour comparison and contribution of Anopheles coluzzii and Anopheles gambiae, two sibling species living in sympatry, to malaria transmission in Alibori and Donga region, northern Benin, West Africa. Malaria Journal 2018, 17: 307. Mlacha YP, Chaki PP, Muhili A, Massue DJ, Tanner M, Majambere S, Killen GF, Govella NJ: Reduced human-biting preferences of the African malaria vectors Anopheles arabiensis and Anopheles gambiae in an urban context: controlled, competitive host-preference experiments in Tanzania. Malaria Journal 2020, 19: 418. Takken W, Verhulst NO: Host Preferences of Blood-Feeding Mosquitoes. Annual Review of Entomology 2013, 58: 433-453. Macdonald G: Epidemiological basis of malaria control. Bull World Health Organ 1956, 15: 613-626. McMillan BE, Britch SC, Golden FV, Aldridge RL, Moreno BJ, Bayer BE, Linthicum KJ: Assessing transfluthrin mortality against Aedes aegypti and Culex quinquefasciatus inside and outside US military tents in a northern Florida environment. Current Research in Parasitology & Vector-Borne Diseases 2022, 2: 100067. WHO: Guidelines for malaria vector control. Geneva, Switzerland: World Health Organization 2023. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 31 Jul, 2024 Read the published version in Malaria Journal → Version 1 posted Editorial decision: Revision requested 06 May, 2024 Reviews received at journal 01 May, 2024 Reviews received at journal 15 Apr, 2024 Reviewers agreed at journal 04 Apr, 2024 Reviewers agreed at journal 04 Apr, 2024 Reviewers agreed at journal 24 Feb, 2024 Reviewers invited by journal 19 Feb, 2024 Editor assigned by journal 14 Feb, 2024 Submission checks completed at journal 14 Feb, 2024 First submitted to journal 13 Feb, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3954730","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":272799522,"identity":"356e251b-c36f-4720-9668-d48b0414cdb9","order_by":0,"name":"Augustin Fongnikin","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Augustin","middleName":"","lastName":"Fongnikin","suffix":""},{"id":272799523,"identity":"ae0b9b9c-e4ce-4d9a-8921-ec4bff9fdec1","order_by":1,"name":"Juniace Ahoga","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Juniace","middleName":"","lastName":"Ahoga","suffix":""},{"id":272799524,"identity":"4fe2b775-1aaa-4783-a56d-fbab76b1d547","order_by":2,"name":"Boris Ndombidje","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Boris","middleName":"","lastName":"Ndombidje","suffix":""},{"id":272799525,"identity":"6b75ada2-b954-4039-a84d-4edbbec2eb64","order_by":3,"name":"Corneille Hueha","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Corneille","middleName":"","lastName":"Hueha","suffix":""},{"id":272799526,"identity":"777019ab-69a3-4e01-93f3-582e7d06fc4b","order_by":4,"name":"Esperantos Souza","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Esperantos","middleName":"","lastName":"Souza","suffix":""},{"id":272799527,"identity":"78ee3636-9cd2-4905-bc57-54eced962863","order_by":5,"name":"Ruth Oti-Tossou","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Ruth","middleName":"","lastName":"Oti-Tossou","suffix":""},{"id":272799528,"identity":"93358d71-df53-4395-93ef-80adff91869f","order_by":6,"name":"Renaud Govoetchan","email":"","orcid":"","institution":"Centre de Recherches Entomologiques de Cotonou (CREC)","correspondingAuthor":false,"prefix":"","firstName":"Renaud","middleName":"","lastName":"Govoetchan","suffix":""},{"id":272799529,"identity":"2454544e-18ed-4b25-bfa0-7cdbb1a9acfc","order_by":7,"name":"Corine Ngufor","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBklEQVRIiWNgGAWjYJCCAxCK8QEDQ4UFgwFMWIKwFmag4jMSDAZsRGhhgGthbCNCC39778PDBRUMefIRyYyPK+dJ2JvLdycw/KhhSJzZgF2LxJnjBodnnGEoNryRzGx4dptE4s423g2MPccYEmfjsMVAIo3hMG8bQ+LGGfnHJBu3SSQYHOPdwMDbwJA4D6+WfyAtyWySjXMk7EFaGP8S1AJUMF8CpKVBgnEDUAszSASXwyTOHGM4zHNMInEDz2NmwwYQ41juhsMyxySMcXmfv72N+TNPjU3i/PZkxocNNTb2BofPbnz4psZGdsYBHNZALWMwQFZwgKiIlMfhjFEwCkbBKBgFDAB3cFdDGKjDYgAAAABJRU5ErkJggg==","orcid":"","institution":"Panafrican Malaria Vector Research Consortium (PAMVERC)","correspondingAuthor":true,"prefix":"","firstName":"Corine","middleName":"","lastName":"Ngufor","suffix":""}],"badges":[],"createdAt":"2024-02-14 00:14:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3954730/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3954730/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12936-024-05043-5","type":"published","date":"2024-07-31T15:57:26+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":51195856,"identity":"113f6c5e-a42e-4463-b3d3-f3980b663e99","added_by":"auto","created_at":"2024-02-15 18:45:45","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":58118,"visible":true,"origin":"","legend":"\u003cp\u003eStudy flow chart\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/cd17cbe5353e9117fee3512f.jpg"},{"id":51195858,"identity":"fdd95896-da3f-4fee-8729-161f4ac494ca","added_by":"auto","created_at":"2024-02-15 18:45:45","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":76986,"visible":true,"origin":"","legend":"\u003cp\u003eInstallation of Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e products on home walls\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/becb2c3bd66071fa3bc002b6.jpg"},{"id":51196207,"identity":"f751c35e-0d95-4a30-80fc-c94231b43458","added_by":"auto","created_at":"2024-02-15 18:53:45","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":62771,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eAn gambiae\u003c/em\u003e sl. mosquitoes human landing rate per house per night per study arm\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/c3ac6690d784ea7be275ac90.jpg"},{"id":51195857,"identity":"fc4ba9a0-4f0c-4814-a89f-95a8bb75fb43","added_by":"auto","created_at":"2024-02-15 18:45:45","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":64063,"visible":true,"origin":"","legend":"\u003cp\u003eOverall\u003cstrong\u003e \u003c/strong\u003ehuman biting rate of \u003cem\u003eAnopheles gambiae \u003c/em\u003esl per hour in houses treated with Mosquito Shield\u003csup\u003eTM \u003c/sup\u003ecompared to a placebo\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/cfa184de7c576dba6c5d66e4.jpg"},{"id":51195859,"identity":"b6a35f66-a754-4af5-a42e-7114f61ccaf6","added_by":"auto","created_at":"2024-02-15 18:45:45","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":61204,"visible":true,"origin":"","legend":"\u003cp\u003eMortality rates of \u003cem\u003eAn. gambiae sl\u003c/em\u003e to 0.05%, 0.25% and 0.5% alpha-cypermethrin, 0.75%, 3.75% and 7.5% permethrin. The error bars indicate the 95% confidence intervals.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/2345e183dbf4f8974c7c7f4f.jpg"},{"id":61794242,"identity":"306a1194-a316-4b87-9522-24ec0cd5982f","added_by":"auto","created_at":"2024-08-05 16:17:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1825356,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3954730/v1/ff4bf91c-f058-4735-80bc-b9be72645f45.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eMosquito Shield\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003eTM\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e, a transfluthrin passive emanator, protects against pyrethroid-resistant \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eAnopheles gambiae\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e s.l in central Benin\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eVector control through the large-scale deployment of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) contributed substantially to the remarkable reductions in malaria burden between 2000 and 2015 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Global progress against malaria has unfortunately stalled in recent years and is expected to go further off course if no additional measures are implemented [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. This stalled progress has been attributed to several factors including the development of vector resistance to the insecticides used on ITNs and IRS, poor access and durability of ITNs and reduced funding for malaria control. This highlights the need to both strengthen the impact of existing tools and bring to market new cost-effective vector control interventions to fill gaps in protection and facilitate advancements towards global malaria elimination targets.\u003c/p\u003e \u003cp\u003eSpatial repellents are airborne repellent compounds that alter mosquito behaviours inducing movement away from a chemical stimulus and interfering with host detection and feeding. By disrupting the mosquito\u0026rsquo;s host-seeking behaviour when volatilised into the air within a given area, they reduce human vector contact and thus provide personal and household protection potentially reducing disease transmission [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Commercial spatial repellent products such as mosquito coils, and electrical plug-ins are widely available for protection from mosquito bites however, they require a heat source to volatize the active ingredient and disperse adequate concentrations into the target area resulting in poor user compliance and health risks associated with the smoke generated by burning [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Passive emanator spatial repellents were developed to provide a volatile concentration of the repellent active ingredient at room temperature from a point source using only natural airflow thus requiring little to no compliance from the user [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Their efficacy against \u003cem\u003eAedes\u003c/em\u003e mosquito vectors of diseases such as dengue, chikungunya and Zika has been demonstrated in multiple studies [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMosquito Shield\u0026trade;, a transfluthrin passive emanator developed by SC Johnson \u0026amp; Son Inc, is a spatial repellent product designed to be easy to use with minimal handling, which may help to increase user compliance and acceptability. It can be hung in semi-enclosed and enclosed spaces to continuously protect against bites from mosquitoes. The emanator consists of a multilayer plastic film pre-treated with 110 mg of transfluthrin which passively emanates using natural airflow to protect people from mosquitoes in a specific area. Previous studies in Peru demonstrated the potential of an earlier prototype of Mosquito Shield\u0026trade; to provide substantial reductions in human-vector contact and Aedes-borne viral disease transmission [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. A cluster randomised controlled trial (RCT) in Indonesia showed a 60% protective efficacy against malaria infection in moderate to high-risk clusters that received the product [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Further RCTs to determine the public health value of Mosquito Shield\u0026trade; as part of the required evidence for the endorsement of the intervention by the World Health Organisation (WHO) for malaria control, are ongoing in Kenya [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] and Mali [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In addition to RCTs, small-scale entomological studies investigating the impact of spatial repellent passive emanators against local malaria vectors may help guide their deployment. Several semi-field entomological trials conducted in East Africa have demonstrated the capacity of transfluthrin-based spatial repellent products including Mosquito Shield\u0026trade; to protect humans from malaria mosquito bites [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. There is however little to no evidence of their entomological performance in West Africa where local vectors have historically exhibited higher levels of pyrethroid resistance [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWe performed a small-scale household randomised trial to assess the entomological efficacy of Mosquito Shield\u0026trade; in households in the Zakpota District of central Benin where the local vector population shows a high intensity of resistance to pyrethroids. Thirty households recruited from the study area were randomised to receive Mosquito Shield\u0026trade; or a placebo product and performance was assessed in terms of the reduction in landing rates of wild vector mosquitoes on humans in Mosquito Shield\u0026trade; treated households compared to the placebo-treated households.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy area\u003c/h2\u003e \u003cp\u003eThe study was performed in the Ganhoua village situated in the Za-Kpota District (7.2384\u0026deg; N, 2.2040\u0026deg; E) of the Zou Department of Benin. Results from a recent entomological survey conducted in the Za-Kpota District showed that the main vector, \u003cem\u003eAn. gambiae sl\u003c/em\u003e, consisting of ~\u0026thinsp;45% \u003cem\u003eAn. colluzi\u003c/em\u003e and ~\u0026thinsp;55% \u003cem\u003eAn\u003c/em\u003e. \u003cem\u003egambiae\u003c/em\u003e ss and is highly resistant to pyrethroids with high levels of kdr (\u0026gt;\u0026thinsp;80%) and overexpressed P450 enzymes [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and sample size considerations\u003c/h2\u003e \u003cp\u003eThis was a two-armed single-blinded small-scale household randomised entomological trial with houses as units of observation. The evaluation was performed in a total of 30 houses; 15 were randomly allocated to receive the Mosquito Shield\u0026trade; product and the remainder received a placebo that was similar to the product but did not contain the active ingredient. Based on human landing rates of the main malaria vector per house per night observed in a previous study in the study area, with a total of 12 collection nights in each house through the life of the product, the study design had\u0026thinsp;\u0026gt;\u0026thinsp;80% power to detect a 25% reduction in human landing rates with Mosquito Shield\u0026trade;. After the recruitment of households, a baseline survey was conducted to assess household characteristics, mosquito species composition and human landing rates in each house. Treatments were then applied, and houses were assessed for the impact of the product on human landing rates of the major malaria vector at specific time points throughout the life of the product. Householders and mosquito collectors were blinded to the intervention applied in each house.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eRecruitment and allocation of participating households\u003c/h2\u003e \u003cp\u003eApproximately forty-five (45) households were initially recruited at baseline. Houses were recruited within a 2.5 km transect of the village and were within 10\u0026ndash;15 minutes walking distance from each other. Households with pregnant and/or nursing mothers were excluded. The study details and frequency of sampling were explained to householders by the study team in their local language with support from community health workers. Following recruitment, a baseline survey was conducted to collect data on the construction characteristics, presence of ITNs and frequency of use of vector control products in each household. To help guide the deployment of the product, measurements were taken of each room in the recruited household. Baseline entomological indices for malaria vectors including species composition and human landing rates, were collected via human landing catches (HLC). Out of the 45 households recruited at baseline, thirty (30) were included in the evaluation (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Houses showing very low vector mosquito landing rates and high use of consumer vector control products (coils, sprays, repellents etc) at baseline were excluded. Households included in the evaluation also agreed to not use consumer vector control products during the study. Selected households were then randomly allocated to each study arm based on baseline \u003cem\u003eAn gambiae\u003c/em\u003e sl human landing rates. Randomisation was performed multiple times to ensure that both study arms were similar in terms of \u003cem\u003eAn gambiae\u003c/em\u003e sl human landing rates at baseline.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eInstallation of Mosquito Shield\u003csup\u003e\u0026trade;\u003c/sup\u003e products\u003c/h2\u003e \u003cp\u003eAll rooms in study houses were between 9m\u003csup\u003e2\u003c/sup\u003e and 18m\u003csup\u003e2\u003c/sup\u003e in size thus requiring 4 Mosquito Shield\u0026trade; products per room per house (1 per wall) as indicated by the manufacturer\u0026rsquo;s instructions. Installation was done by the study team in each study house. Products were fixed on walls using nails and small pieces of wood and were placed at approximately two-thirds of the wall height from the ground (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Placebo products were installed using the same method. A total of 140 Mosquito Shield\u0026trade; and 132 placebo products were installed in the houses included in the study.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eMosquito sampling and processing\u003c/h2\u003e \u003cp\u003eThe trial was performed from April to May 2022 and lasted for the duration of the efficacy of the Mosquito Shield\u0026trade; product (32 days). Mosquitoes were sampled in recruited houses once at baseline and 6 times within the life of the product (0\u0026ndash;1, 7\u0026ndash;8, 14\u0026ndash;15, 21\u0026ndash;22, 28\u0026ndash;29, 31\u0026ndash;32 days) post-treatment application, using HLC. Sampling was done for 2 consecutive nights at each round of sampling in one dedicated room in each house. Consenting human volunteer mosquito collectors working in pairs collected mosquitoes landing on their legs overnight from 7 pm to 7 am in each house on each sampling day. Collections were done in two shifts each night (7 pm to 1 am and 1 am to 7 am). The collectors sat on chairs with their lower limbs exposed and collected all mosquitoes which landed on them using sucking tubes. To characterize \u003cem\u003eAnopheles\u003c/em\u003e biting time behaviour, collections were recorded per hour. To control human attractiveness to mosquitoes, for each collection round, human collector pairs were rotated between houses in the intervention arm and the placebo arm on successive nights.\u003c/p\u003e \u003cp\u003eIn the morning, all collected mosquitoes were transported to the laboratory for morphological identification to species level using appropriate taxonomic keys. The date of collection, house identification number and species were recorded for each mosquito. The key outcome measure used to determine the efficacy of Mosquito Shield\u0026trade; in the study houses was the protective efficacy defined as the percentage reduction in human landing rates of malaria vector mosquitoes collected by HLC in households in the treated arm compared to the placebo arm.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eDifferences in the numbers of female \u003cem\u003eAn gambiae\u003c/em\u003e sl landing per person per household were analysed using mixed effects negative binomial regression in STATA version 17 with treatments and collection timepoint added as fixed effects and households as random effects. Vector incidence rate ratios (IRR) between the Mosquito Shield\u0026trade; and placebo arms and 95% confidence intervals were calculated for the entire duration of the study and for each sampling timepoint.\u003c/p\u003e \u003cp\u003eOverall efficacy was expressed in terms of the protective efficacy (PE) against mosquito landing rates in the Mosquito Shield\u0026trade; arm relative to the control placebo arm which was calculated as follows:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$PE=(1-IRR)\\times 100$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere IRR is the incidence rate ratio in the Mosquito Shield\u0026trade; group compared to the placebo group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eEthical considerations\u003c/h2\u003e \u003cp\u003e The study received ethical approval from the ethics review committee of the Ministry of Health in Benin (CNERS, No. 54). Informed consent was obtained from the head of each participating household and mosquito collectors before they participated in the study (Appendix 3). The consent forms and participant information sheets were explained to them in their local language. An impartial witness was used when participants could not read or write. Mosquito collectors were offered chemoprophylaxis during the study. A study nurse was available to examine any cases of fever and any collectors found positive for malaria, were treated free of charge during the study and up to 4 weeks after the end of the study. Participants were free to withdraw from the study at any time.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eSusceptibility tests\u003c/h2\u003e \u003cp\u003eTo determine the frequency of insecticide resistance in the wild vector population of the study area during the trial, WHO cylinder bioassays were performed on 2 to 5 days old adult F1 female mosquitoes emerging from larvae collected from breeding sites around the study houses. Approximately 100 female mosquitoes per insecticide were exposed for 1 h in batches of 25 to alpha-cypermethrin 0.05% and permethrin 0.75% and to filter papers treated at the 1x, 5x and 10x the diagnostic doses of these insecticides. Knockdown was recorded after 1 h and mortality after a 24 h holding period.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eBaseline characteristics of participating households\u003c/h2\u003e \u003cp\u003eThe average number of inhabitants per household among the 30 households included in the study was 2 and this was similar between households in both study arms (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All households owned at least one LLIN. The proportion of people who reported sleeping under nets every night was 80%. Most nets were PermaNet\u0026reg; 2.0 (13/30) and Yorkool\u0026reg; (14/30). Overall, most houses were made of either cement or a mixture of mud and cement (27/30) and had closed eaves. Two households reported using consumer vector control products on some nights. \u003cem\u003eAn. gambiae sl\u003c/em\u003e was the most abundant mosquito species in the study houses at baseline and represented 73% of the collection. Other species collected in lower densities were \u003cem\u003eMansonia africana\u003c/em\u003e (18%) and \u003cem\u003eCulex quinquefasciatus\u003c/em\u003e (8%).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHousehold characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMosquito Shield\u0026trade;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndicators\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal N of households\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal N of people\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of rooms for sleeping\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean number of persons per house\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eType of housing\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMud\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMud\u0026thinsp;+\u0026thinsp;Cement\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e33.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLLINs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePermaNet 2.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYorkool\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e46.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther LLINs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eUse of LLINs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEvery night (7 nights)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eUse of consumer vector control products\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEvery night (7 nights)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMost nights (5\u0026ndash;6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSome night (1\u0026ndash;4 nights)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNot used last week\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eSpecies composition and overall mosquito landing rates post-intervention\u003c/h2\u003e \u003cp\u003eA total of 5,736 female mosquitoes were collected in the placebo arm and 3,862 female mosquitoes in the Mosquito Shield\u0026trade; arm post-intervention giving an overall reduction in mosquito landing rates of 32.67% (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The largest proportion of mosquito species collected were \u003cem\u003eAnopheles gambiae sl\u003c/em\u003e followed by \u003cem\u003eCulex spp\u003c/em\u003e and \u003cem\u003eMansonia spp\u003c/em\u003e. Small numbers of secondary malaria vectors (\u003cem\u003eAn pharoensis\u003c/em\u003e and \u003cem\u003eAn ziemani\u003c/em\u003e) were also collected. Species composition in terms of the proportion of each species, was generally similar across both study arms. Overall, for each mosquito genera, lower numbers were collected in houses in the Mosquito Shield\u0026trade; arm compared to the placebo arm (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) and these differences were significant for \u003cem\u003eAnopheles\u003c/em\u003e, \u003cem\u003eCulex\u003c/em\u003e and \u003cem\u003eMansonia\u003c/em\u003e mosquitoes (26.57% \u0026minus;\u0026thinsp;35.20%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Reductions in \u003cem\u003eAedes aegypti\u003c/em\u003e were observed though the numbers collected were too few (13).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTotal numbers and species composition of mosquitoes collected by HLC per study arm\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSpecies\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eReduction in numbers collected (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAnopheles gambiae s.l.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4831\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3263\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e84.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e32.46\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAnopheles pharoensis\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e47.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAnopheles ziemani\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e91.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAedes aegypti\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e84.62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCulex species\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e358\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e232\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e35.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eMansonia species\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e429\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e315\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e26.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTotal\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5736\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3862\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e32.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eReduction in human landing rates of\u003c/b\u003e \u003cb\u003eAn. gambiae sl\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe \u003cem\u003eAn gambiae\u003c/em\u003e sl landing rates in both study arms at each time point and reductions observed with Mosquito Shield\u0026trade; relative to the placebo control arm are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Landing rates were lower at baseline compared to post-intervention time points and this can be attributed to local changes in vector density over time. Landing rates were generally lower in houses in the Mosquito Shield\u0026trade; arm compared to the placebo control arm at all 6 post-intervention sampling timepoints and these differences were significant at most time points (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Overall, mosquito landing was significantly lower in houses with Mosquito Shield\u0026trade; (18.13 bites per person per night) compared to the placebo control (26.84 bites per person per night, IRR\u0026thinsp;=\u0026thinsp;0.658, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The protective efficacy of Mosquito Shield\u0026trade; was lowest in the first round of collection (9.1% at 0\u0026ndash;1-day, p\u0026thinsp;=\u0026thinsp;0.335) but increased in the subsequent time points and ranged from 18.1\u0026ndash;59%. This was probably due to the product taking some time to build up the volatile AI in the treated houses.\u003c/p\u003e \u003cp\u003eMosquito Shield\u0026trade; provided a significant overall protective efficacy of 34.2% (22.1%-44.4%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) post-intervention. Hourly biting rates of \u003cem\u003eAn. gambiae sl\u003c/em\u003e were also consistently higher in the placebo control arm compared to the Mosquito Shield\u0026trade; arm at all times of the night (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A larger reduction in mosquito biting was observed in the early morning hours (4:00 am to 7:00 am) with Mosquito Shield\u0026trade; compared to the placebo.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHuman landing rates and protective efficacy of Mosquito Shield\u0026trade; against wild \u003cem\u003eAn gambiae sl\u003c/em\u003e in households in Ganhoua village, Zakpota sub-district, Benin\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime point\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eArm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal collected\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePerson nights\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHBR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eIRR \u003c/p\u003e \u003cp\u003e(95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e% Protective efficacy (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eBaseline\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e346\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e11.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.012\u003c/p\u003e \u003cp\u003e(0.834\u0026ndash;1.226)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003en/a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.907\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e350\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e11.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0\u0026ndash;1 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e879\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e29.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.909\u003c/p\u003e \u003cp\u003e(0.749\u0026ndash;1.104)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003cp\u003e(0-25.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.335\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e799\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e7\u0026ndash;8 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e33.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.410\u003c/p\u003e \u003cp\u003e(0.309\u0026ndash;0.544)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e59\u003c/p\u003e \u003cp\u003e(45.6\u0026ndash;69.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e428\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e14\u0026ndash;15 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e719\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e23.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.819\u003c/p\u003e \u003cp\u003e(0.535\u0026ndash;1.255)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e18.1\u003c/p\u003e \u003cp\u003e(0-46.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.359\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e589\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e21\u0026ndash;22 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e676\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.779\u003c/p\u003e \u003cp\u003e(0.654\u0026ndash;0.927)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e22.1\u003c/p\u003e \u003cp\u003e(7.3\u0026ndash;54.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e535\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17.83\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e29\u0026ndash;30 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e822\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e27.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.540 \u003c/p\u003e \u003cp\u003e(0.452\u0026ndash;0.644)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e46\u003c/p\u003e \u003cp\u003e(35.6\u0026ndash;54.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e31\u0026ndash;32 days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e728\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.599 \u003c/p\u003e \u003cp\u003e(0.463\u0026ndash;0.774)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e40.1\u003c/p\u003e \u003cp\u003e(22.6\u0026ndash;53.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e462\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTotal (post intervention)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlacebo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4831\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e180\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.658\u003c/p\u003e \u003cp\u003e(0.556\u0026ndash;0.779)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e34.2\u003c/p\u003e \u003cp\u003e(22.1\u0026ndash;44.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMosquito Shield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3263\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e180\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e18.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eSusceptibility test results\u003c/h2\u003e \u003cp\u003eMortality rates of the susceptible laboratory-maintained \u003cem\u003eAn gambiae\u003c/em\u003e ss Kisumu strain after exposure to permethrin and alpha-cypermethrin treated papers in WHO cylinder bioassays were both 100%. With the wild \u003cem\u003eAn gambiae\u003c/em\u003e sl from the study area (Ganhoua), mortality rates were 37% at 1X, 80% at 5x and 75% for permethrin and 25% at 1x, 78% at 5X and 77% at 10X for alpha-cypermethrin (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e) showing that the wild strain had a high intensity of resistance to both pyrethroid insecticides.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe purpose of this study was to evaluate the impact of Mosquito Shield\u0026trade;, a transfluthrin passive emanator on human landing rates of wild free-flying high-intensity pyrethroid-resistant \u003cem\u003eAnopheles gambiae\u003c/em\u003e sl in houses in the Ganhoua village in the Zakpota district of central Benin. The data showed a significant protective effect of 34.2% against malaria mosquitoes in Mosquito Shield\u0026trade; treated houses relative to houses treated with a placebo. The intervention remained efficacious through its 1-month product span. The findings demonstrate the impact of a transfluthrin passive emanator against local malaria vectors in Benin for the first time and corroborate multiple studies that have shown the potential of spatial repellents to protect humans from vector mosquitoes in other countries [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe levels of protective efficacy achieved with Mosquito Shield\u0026trade; in this study (34.2%) were nevertheless lower than what was observed against \u003cem\u003eAn arabiensis\u003c/em\u003e (70% protective efficacy) in a recent experimental hut trial in Tanzania, East Africa [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. The difference in outcome between both studies could be attributed to higher intensities of pyrethroid resistance in the \u003cem\u003eAn gambiae\u003c/em\u003e sl population in the Benin study and/or to inherent differences in vector species. The \u003cem\u003eAn gambiae\u003c/em\u003e sl vector population in Benin is highly anthropophagic, feeding almost entirely on humans indoors [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], while \u003cem\u003eAn arabiensis\u003c/em\u003e tends to be more zoophilic and is less attracted to humans compared to \u003cem\u003eAn gambiae\u003c/em\u003e sl [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Susceptibility bioassays showed that the Benin vector population had a high intensity of resistance to pyrethroids with mosquito mortality remaining below 80% even at doses 10 times the diagnostic dose of permethrin and alpha-cypermethrin. This high intensity of resistance to the pyrethroids coupled with the higher local vector attractiveness to humans may therefore have reduced the capacity of the transfluthrin passive emanator to sufficiently modify the mosquitoes\u0026rsquo; host-seeking behaviour in the Benin study and induce greater levels of protection.\u003c/p\u003e \u003cp\u003eWhile it is unclear how reductions in mosquito landing rates will impact malaria incidence and prevalence, traditional malaria transmission models indicate that reducing human landing rates and thus human vector contact even at the levels demonstrated in this study can have major effects on the vectorial capacity of a vector population [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Our findings therefore show the potential of the Mosquito Shield\u0026trade; spatial repellent device to reduce malaria transmission by pyrethroid-resistant \u003cem\u003eAn gambiae\u003c/em\u003e sl vector mosquitoes to individuals in treated households with high ITN use in a West African setting where vectors historically exhibit high intensities of pyrethroid resistance [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Results from the ongoing RCT of Mosquito Shield\u0026trade; in Mali [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] may further elucidate the epidemiological impact of the intervention on clinical malaria when applied at a community scale in the region.\u003c/p\u003e \u003cp\u003eThe Mosquito Shield\u0026trade; product was designed to last approximately 1 month, and, in this study, we demonstrated its efficacy for this period. However, mosquito transmission seasons in endemic countries typically last several months hence it is expected that under operational conditions, the Mosquito Shield\u0026trade; product will have to be replaced multiple times in houses to cover the entire transmission season. While installation was relatively easy for the study team, requiring less than 15 minutes per house, the process can be very demanding for householders if it must be done too frequently. To overcome this challenge, an advanced longer-lasting version of the transfluthrin passive emanators has been developed by the manufacturer and is undergoing evaluation in semi-field studies across Africa.\u003c/p\u003e \u003cp\u003eMosquito Shield\u0026trade; induced substantial reductions in human landing rates of \u003cem\u003eCulex\u003c/em\u003e and \u003cem\u003eMansonia\u003c/em\u003e (26\u0026ndash;35%) mosquitoes, vectors of human filariasis, in treated houses compared to the placebo. Reductions in densities of such nuisance mosquitoes have been reported in multiple small-scale trials of transfluthrin spatial repellents [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Protection from nuisance mosquitoes is usually associated with an increased uptake of malaria vector control interventions. This finding may therefore have positive implications for the acceptability of Mosquito Shield\u0026trade; to householders. Further studies investigating user acceptance at both household and community levels are advisable.\u003c/p\u003e \u003cp\u003eThis study evaluated the entomological impact of transfluthrin passive emanators in households which had pyrethroid-only nets in them. Following WHO\u0026rsquo;s recent endorsement of dual active ingredient nets, [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], many endemic countries are replacing pyrethroid-only nets with these new more effective nets. Passive emanators will therefore likely be deployed against a background of high coverage with dual AI nets. Studies investigating their potential to complement dual AI nets may help guide local deployment strategies.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur study demonstrated a 34.2% protective efficacy of Mosquito Shield\u0026trade;, a transfluthrin passive emanator, against a high-intensity wild pyrethroid-resistant malaria vector population when applied in houses in Benin. Mosquito Shield\u0026trade; remained protective throughout its product life of 30 days. The passive emanator shows potential to improve the control of malaria transmitted by pyrethroid-resistant \u003cem\u003eAn gambiae\u003c/em\u003e sl vector mosquitoes and to help cover gaps in malaria control that may exist with core vector control tools.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eITN: Insecticide treated nets\u003c/p\u003e\n\u003cp\u003eIRS: Indoor residual spraying\u003c/p\u003e\n\u003cp\u003eWHO: World Health Organization\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAI: Active ingredient\u003c/p\u003e\n\u003cp\u003eHLC: Human landing catches\u003c/p\u003e\n\u003cp\u003eHBR: Human biting rate\u003c/p\u003e\n\u003cp\u003eIIR: Incidence Rate Ratio\u003c/p\u003e\n\u003cp\u003eRCT: Randomised controlled trials\u003c/p\u003e\n\u003cp\u003eCREC: Centre de Recherche Entomologique de Cotonou\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLSHTM: London School of Hygiene \u0026amp; Tropical Medicine\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePAMVERC: Pan African Malaria Vector Research Consortium\u003c/p\u003e\n\u003cp\u003eAIRID: African Institute for Research in Infectious Diseases\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAvailability of data and material\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding authors on reasonable request.\u003c/p\u003e\n\u003ch2\u003eCompeting interests\u003c/h2\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch2\u003eFunding\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eThis project is supported by a grant to Corine Ngufor from SC Johnson \u0026amp; Son Inc. The funders have no role in study design, data collection and analysis and the decision to publish this manuscript.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAuthors’ contributions\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eCN designed the study and supervised its implementation. AF, JA ES and RO performed the entomological surveys and susceptibility bioassays with support from BN. CH was responsible for data management and processing. CN, RG and AF analysed the data and prepared the manuscript tables and figures. CN wrote the manuscript text with support from AF. All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAcknowledgements\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eWe thank Dr. Thomas Mascari and Ms Madeleine Chura of SC Johnson \u0026amp; Son Inc for providing the test items and for their support. We appreciate the study participants and community leaders of Ganhoua village of the Za-Kpota District for their participation, support and collaboration. 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Vector-Borne Diseases \u003c/em\u003e2022, \u003cstrong\u003e2:\u003c/strong\u003e100067.\u003c/li\u003e\n\u003cli\u003eWHO: \u003cstrong\u003eGuidelines for malaria vector control.\u003c/strong\u003e \u003cem\u003eGeneva, Switzerland: World Health Organization \u003c/em\u003e2023.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"malaria-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"malj","sideBox":"Learn more about [Malaria Journal](http://malariajournal.biomedcentral.com/)","snPcode":"12936","submissionUrl":"https://submission.nature.com/new-submission/12936/3","title":"Malaria Journal","twitterHandle":"@malariajournal","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3954730/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3954730/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Spatial repellents can provide personal and household protection against biting vector mosquitoes by volatising repellents into the air within a given area. Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e is a transfluthrin passive emanator undergoing evaluation for malaria control. Studies evaluating its entomological impact against different local malaria vector populations would help guide its deployment in endemic countries.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e We performed a two-arm single-blinded small-scale household randomised entomological trial to assess the impact of Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e on the human landing rate of wild pyrethroid-resistant \u003cem\u003eAnopheles gambiae\u003c/em\u003e sl vector mosquitoes in houses in the Ganhoua village of the Zakpota District of central Benin. From a total of 30 houses, 15 were randomly allocated to receive Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e while the remainder received a placebo product. The trial lasted through the life of the Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e product (32 days). Mosquito sampling was performed by human landing catches at baseline and at 6 timepoints post-intervention (days 0-1, 7-8, 14-15, 21-22, 28-29 and 31-32). Collections were performed for 2 days at each sampling time point. WHO cylinder bioassays were conducted during the trial with F1, \u003cem\u003eAn\u003c/em\u003e \u003cem\u003egambiae\u003c/em\u003e sl mosquitoes that emerged from larvae from the study area to assess the intensity of resistance to pyrethroids in the wild vector population.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFindings:\u003c/strong\u003e The vector population in the study area showed a high intensity of resistance to pyrethroids. Baseline \u003cem\u003eAn gambiae \u003c/em\u003esl human landing rates were similar in houses in both study arms before product application (11.53/person/night vs 11.67/person/night, p\u0026gt;0.05). A total of 5736 mosquitoes were collected in the placebo control arm and 3862 in the Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e arm post-intervention. Overall \u003cem\u003eAn\u003c/em\u003e \u003cem\u003egambiae\u003c/em\u003e sl human landing rates post-intervention were significantly lower in houses in the Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e arm 18.13/person/night) compared to the houses in the placebo control arm (26.84/person/night, IRR=0.658, p\u0026lt;0.001). Over the lifespan of the product, Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e provided a significant protective efficacy of 34.2% (22.1%-44.4%, p\u0026lt;0.001) against wild pyrethroid-resistant \u003cem\u003eAn gambiae\u003c/em\u003e s.l. vectors compared to the placebo. Human landing rates of other nuisance vector mosquito species (\u003cem\u003eCulex\u003c/em\u003e and \u003cem\u003eMansonia\u003c/em\u003e) were also reduced in houses treated with Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e compared to the placebo.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: Mosquito Shield\u003csup\u003eTM\u003c/sup\u003e, a transfluthrin passive emanator, provided significant protection against pyrethroid-resistant malaria vectors to households in Benin. The spatial repellent shows potential to reduce malaria transmission by pyrethroid-resistant \u003cem\u003eAn\u003c/em\u003e \u003cem\u003egambiae\u003c/em\u003e sl vector mosquitoes and cover gaps in malaria control when deployed to complement existing vector control interventions.\u003c/p\u003e","manuscriptTitle":"Mosquito ShieldTM, a transfluthrin passive emanator, protects against pyrethroid-resistant Anopheles gambiae s.l in central Benin","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-15 18:45:40","doi":"10.21203/rs.3.rs-3954730/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-05-07T01:16:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-01T08:29:09+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-15T14:25:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"09a11f47-0aff-4a73-8555-46b2813ef61e","date":"2024-04-04T06:40:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"90454289-9487-405b-8192-4a8b38bb78ea","date":"2024-04-04T04:37:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"0611c31b-d26e-40b9-b0bb-f2769b1b15ed","date":"2024-02-24T20:13:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-02-19T20:01:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-02-14T09:42:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-02-14T09:42:44+00:00","index":"","fulltext":""},{"type":"submitted","content":"Malaria Journal","date":"2024-02-14T00:09:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"malaria-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"malj","sideBox":"Learn more about [Malaria Journal](http://malariajournal.biomedcentral.com/)","snPcode":"12936","submissionUrl":"https://submission.nature.com/new-submission/12936/3","title":"Malaria Journal","twitterHandle":"@malariajournal","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5a2d6eda-d622-48b3-8b3e-a69ec4116274","owner":[],"postedDate":"February 15th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-08-05T16:13:12+00:00","versionOfRecord":{"articleIdentity":"rs-3954730","link":"https://doi.org/10.1186/s12936-024-05043-5","journal":{"identity":"malaria-journal","isVorOnly":false,"title":"Malaria Journal"},"publishedOn":"2024-07-31 15:57:26","publishedOnDateReadable":"July 31st, 2024"},"versionCreatedAt":"2024-02-15 18:45:40","video":"","vorDoi":"10.1186/s12936-024-05043-5","vorDoiUrl":"https://doi.org/10.1186/s12936-024-05043-5","workflowStages":[]},"version":"v1","identity":"rs-3954730","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3954730","identity":"rs-3954730","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}