Community perceptions and acceptance of ivermectin for malaria control on Sumba Island, Indonesia

Community perceptions and acceptance of ivermectin for malaria control on Sumba Island, Indonesia | medRxiv /* */ /* */ <!-- <!-- /*! * yepnope1.5.4 * (c) WTFPL, GPLv2 */ (function(a,b,c){function d(a){return"[object Function]"==o.call(a)}function e(a){return"string"==typeof a}function f(){}function g(a){return!a||"loaded"==a||"complete"==a||"uninitialized"==a}function h(){var a=p.shift();q=1,a?a.t?m(function(){("c"==a.t?B.injectCss:B.injectJs)(a.s,0,a.a,a.x,a.e,1)},0):(a(),h()):q=0}function i(a,c,d,e,f,i,j){function k(b){if(!o&&g(l.readyState)&&(u.r=o=1,!q&&h(),l.onload=l.onreadystatechange=null,b)){"img"!=a&&m(function(){t.removeChild(l)},50);for(var d in y[c])y[c].hasOwnProperty(d)&&y[c][d].onload()}}var j=j||B.errorTimeout,l=b.createElement(a),o=0,r=0,u={t:d,s:c,e:f,a:i,x:j};1===y[c]&&(r=1,y[c]=[]),"object"==a?l.data=c:(l.src=c,l.type=a),l.width=l.height="0",l.onerror=l.onload=l.onreadystatechange=function(){k.call(this,r)},p.splice(e,0,u),"img"!=a&&(r||2===y[c]?(t.insertBefore(l,s?null:n),m(k,j)):y[c].push(l))}function j(a,b,c,d,f){return q=0,b=b||"j",e(a)?i("c"==b?v:u,a,b,this.i++,c,d,f):(p.splice(this.i++,0,a),1==p.length&&h()),this}function k(){var a=B;return a.loader={load:j,i:0},a}var l=b.documentElement,m=a.setTimeout,n=b.getElementsByTagName("script")[0],o={}.toString,p=[],q=0,r="MozAppearance"in l.style,s=r&&!!b.createRange().compareNode,t=s?l:n.parentNode,l=a.opera&&"[object Opera]"==o.call(a.opera),l=!!b.attachEvent&&!l,u=r?"object":l?"script":"img",v=l?"script":u,w=Array.isArray||function(a){return"[object Array]"==o.call(a)},x=[],y={},z={timeout:function(a,b){return b.length&&(a.timeout=b[0]),a}},A,B;B=function(a){function b(a){var a=a.split("!"),b=x.length,c=a.pop(),d=a.length,c={url:c,origUrl:c,prefixes:a},e,f,g;for(f=0;f<d;f++)g=a[f].split("="),(e=z[g.shift()])&&(c=e(c,g));for(f=0;f<b;f++)c=x[f](c);return c}function g(a,e,f,g,h){var i=b(a),j=i.autoCallback;i.url.split(".").pop().split("?").shift(),i.bypass||(e&&(e=d(e)?e:e[a]||e[g]||e[a.split("/").pop().split("?")[0]]),i.instead?i.instead(a,e,f,g,h):(y[i.url]?i.noexec=!0:y[i.url]=1,f.load(i.url,i.forceCSS||!i.forceJS&&"css"==i.url.split(".").pop().split("?").shift()?"c":c,i.noexec,i.attrs,i.timeout),(d(e)||d(j))&&f.load(function(){k(),e&&e(i.origUrl,h,g),j&&j(i.origUrl,h,g),y[i.url]=2})))}function h(a,b){function c(a,c){if(a){if(e(a))c||(j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}),g(a,j,b,0,h);else if(Object(a)===a)for(n in m=function(){var b=0,c;for(c in a)a.hasOwnProperty(c)&&b++;return b}(),a)a.hasOwnProperty(n)&&(!c&&!--m&&(d(j)?j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}:j[n]=function(a){return function(){var b=[].slice.call(arguments);a&&a.apply(this,b),l()}}(k[n])),g(a[n],j,b,n,h))}else!c&&l()}var h=!!a.test,i=a.load||a.both,j=a.callback||f,k=j,l=a.complete||f,m,n;c(h?a.yep:a.nope,!!i),i&&c(i)}var i,j,l=this.yepnope.loader;if(e(a))g(a,0,l,0);else if(w(a))for(i=0;i (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0];var j=d.createElement(s);var dl=l!='dataLayer'?'&l='+l:'';j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;j.type='text/javascript';j.async=true;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-P4HH5NV'); Skip to main content Home About Submit ALERTS / RSS Search for this keyword Advanced Search Community perceptions and acceptance of ivermectin for malaria control on Sumba Island, Indonesia Diana Timoria , Christa Dewi , Claus Bøgh , Tri Baskoro , Wisnu Nurcahyo , View ORCID Profile Vincentius Arca Testamenti , Giao Vu Thi Quynh , Lorenz von Seidlein , Kevin Kobylinski , View ORCID Profile Mary Chambers doi: https://doi.org/10.1101/2025.06.04.25329015 Diana Timoria 1 Oxford University Clinical Research Unit , Jakarta, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site Christa Dewi 2 Center for Tropical Medicine, Faculty of Medicine , Public Health and Nursing, Universitas Gadjah Mada , Yogyakarta, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site Claus Bøgh 3 The Sumba Foundation , Sumba Island, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site Tri Baskoro 2 Center for Tropical Medicine, Faculty of Medicine , Public Health and Nursing, Universitas Gadjah Mada , Yogyakarta, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site Wisnu Nurcahyo 4 Department of Parasitology, Faculty of Veterinary Medicine, Universitas Gadjah Madah , Yogyakarta, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site Vincentius Arca Testamenti 2 Center for Tropical Medicine, Faculty of Medicine , Public Health and Nursing, Universitas Gadjah Mada , Yogyakarta, Indonesia Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Vincentius Arca Testamenti Giao Vu Thi Quynh 7 Oxford University Clinical Research Unit , Ho Chi Minh City, Vietnam Find this author on Google Scholar Find this author on PubMed Search for this author on this site Lorenz von Seidlein 5 Mahidol Oxford Tropical Medicine Research Unit, Mahidol University , Bangkok, Thailand 6 Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford , Oxford, United Kingdom Find this author on Google Scholar Find this author on PubMed Search for this author on this site Kevin Kobylinski 5 Mahidol Oxford Tropical Medicine Research Unit, Mahidol University , Bangkok, Thailand Find this author on Google Scholar Find this author on PubMed Search for this author on this site Mary Chambers 6 Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford , Oxford, United Kingdom 7 Oxford University Clinical Research Unit , Ho Chi Minh City, Vietnam Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Mary Chambers For correspondence: mchambers{at}oucru.org Abstract Full Text Info/History Metrics Data/Code Preview PDF Abstract Background Indonesia has made significant progress in malaria control, however hotspots such as Sumba Island continue to experience high rates of malaria transmission, driven by multiple Anopheles mosquito species. The Sumba Livestock Ivermectin for Malaria (SLIM) trial was conducted to assess the efficacy of ivermectin treatment in livestock as a vector control strategy. This study aimed to explore community perceptions of ivermectin-based malaria interventions, including ivermectin livestock treatment (ITL) and potential mass drug administration (MDA) in humans. Methods A social science study was conducted alongside the SLIM trial between November 2022 and September 2023 across four villages in Southwest Sumba. A mixed-methods approach was used, including focus group discussions, in-depth interviews, and feedback meetings. Community engagement activities such as puppet shows and interactive sessions on malaria transmission were also implemented. Data were transcribed, coded, and thematically analysed using NVivo. Results A total of 75 individuals participated in qualitative data collection, and approximately 650 individuals engaged in community events. Malaria was ranked as the most pressing health concern by study participants. Initial skepticism about ITL was mitigated through trust-building efforts and respectful communication. Community members actively contributed to the trial, demonstrating acceptance of ITL and expressing interest in future research participation. While there was openness to mass drug administration for humans, concerns about safety, particularly for children, were raised. Local authority approval was deemed essential for intervention acceptance. In one village, low social cohesion posed barriers to research participation, highlighting the importance of pre-trial engagement. Conclusions Community perceptions of ivermectin-based malaria control strategies were shaped by trust, engagement, and cultural considerations. The study underscores the need for sustained, respectful communication and inclusive stakeholder engagement in malaria research. Future malaria control interventions should account for local social dynamics, ensuring informed community participation to enhance trial feasibility and acceptance. Introduction Since Indonesia established its National Malaria Eradication Unit in 1952, the country has made great strides in reducing the burden of this parasitic, mosquito-borne disease [ 1 ]. Most recently, the Annual Parasite Incidence (API)—measured as the number of cases per 1,000 population—was almost halved, i.e. from 2.0 in 2010 to 1.1 in 2021 [ 2 ]. Up to 89% of the national population now live in malaria-free areas [ 2 ]. Leveraging such progress, the government aims to eliminate malaria nationwide by 2030. This appears an ambitious goal, especially for resource limited eastern Indonesia, which has a disproportionately high burden of malaria. Malaria elimination has proved particularly challenging on Sumba, an island belonging to the eastern province of Nusa Tenggara Timur. In 2022, the island recorded an API of 16.6, which was more than 10 times the national average [ 2 ]. At least 12 species of Anopheles mosquitoes are present on Sumba [ 3 , 4 ], making vector control particularly difficult. However, given the significance of large animals to Sumbanese residents [ 5 – 7 ], with more than 65% of households owning livestock [ 8 ], the island presents an opportunity for testing novel vector control measures by using livestock endectocides. Research from Burkina Faso, South Africa, Kenya, Pakistan and Vietnam has shown that after cattle are injected with ivermectin, their blood is lethal to blood-feeding Anopheles [ 9 – 13 ]. Ivermectin treatment of livestock (ITL), if applied en masse , may substantially disrupt malaria transmission on Sumba. With ITL as a tool for reducing malaria transmission, a veterinary trial entitled Sumba Livestock Ivermectin for Malaria control (SLIM) was implemented on the island from 2022–2023. The trial’s primary objective was to treat cattle and buffalo with short and long-lasting ivermectin formulations, and evaluate the impact on the survival of wild Anopheles [ 14 ]. Alongside the SLIM trial, we conducted a social-science study to understand community acceptance of ivermectin for malaria control. More specifically, we aimed to explore perceptions surrounding the use of mass ITL and ivermectin mass drug administration (MDA) to humans. Methods Study setting and site selection Our study took place on Sumba, part of East Nusa Tenggara province, eastern Indonesia (see Figure 1 ). It is an island of around 11,000km 2 [ 15 ], which was inhabited by close to 800,000 people in 2022 [ 16 ]. In the same year, it remained one of poorest islands in Indonesia, with an overall poverty rate of 29% [ 17 ]. Most Sumbanese adults have only attained a primary-school education and engage in agriculture for a living [ 18 ]. Download figure Open in new tab Figure 1. Map of Sumba Island in eastern Indonesia As a subset of agriculture, livestock farming is a means for many island residents to access food, cash, and even social prestige [ 5 – 7 ]. Of the 150,000 households here, over 90,000 families raise large animals, including cows and buffaloes. Most keep livestock under their houses [ 19 ], which poses as a risk factor for malaria in humans [ 20 ]. In 2022, a total of 13,262 clinical malaria cases were documented on Sumba [ 2 ]. Much of the malaria transmission on the island occurs in the West and Southwest districts of Sumba [ 21 ]. These two districts are largely dominated by the Kodi ethnic group which is the largest group in the western part of the island, least educated and resourced, and has the highest malaria burden. Within this socio-economic context of Sumba, the SLIM trial and the current social-science study approached six villages in the Southwest (Sumba Barat Daya) and West (Sumba Barat) districts of Sumba. These villages were selected due to their Anopheles species diversity and abundance. Two villages turned out to be unfit for investigation. The first village had a damaged mosquito larval habitat following heavy rains from a passing cyclone and a flash flood one month later and thus did not have enough mosquitoes in circulation to be a valid site. The second village presented what we considered an unwillingness to participate in research (more details in the Results section). We were thus left with four villages to conduct fieldwork. Our final site selection included Pandawawi (subvillage Kahale), Matakapore, Waimakaha, and Wainyapu which included two subvillages (Galukoloko and Waikavaroko), which were known to have a high diversity of Anopheles species present. Administratively these villages fall under Southwest Sumba District, each having an average population of 1,500 and an area of approximately 7km 2 [ 22 – 26 ]. Study design and data collection From 16 th November 2022 to 31 st December 2023, we conducted fieldwork in four villages, spending approximately 3 months/site. The current social-science study was designed to accompany the SLIM trial with community engagement and systematic data collection in every village. The community engagement component included puppet shows, board games, drawing/coloring, and viewing mosquitoes under the microscope. In addition, mosquitoes that had fed on ivermectin-treated and untreated livestock were presented to the community so they could personally observe the poisoning effect ivermectin had on the dying mosquitoes. These activities aimed to create opportunities for open discussion with the study communities, to sensitize community members about the SLIM trial and to promote better understanding of malaria (its symptoms as well as transmission). We organized community engagement twice in each village, running a total of eight community-engagement events. Recruitment for the qualitative research component was purposive to include adults (>18yo) from the study villages who were animal owners, and ensure representation of gender. Written consent was given by all participants. The data-collection component included three primary activities. First, we conducted focus group discussions (FGDs) with various village stakeholders to explore their experiences and views of malaria, as well as their possible acceptance of malaria control by ITL (as seen in the SLIM trial), and hypothetically for human MDA to control malaria. During the FGDs we also asked participants to undertake card-sorting, i.e. ranking health issues according to their levels of importance, where each card represented a common disease or ailment on Sumba. Second, we carried out in-depth interviews (IDIs) with women, who were generally not comfortable speaking in the FGD setting. Finally, we organized feedback meetings (FMs) after the completion of the SLIM entomological collections, the purpose of which was to seek their additional insights following the conclusion of the trial activities. In each village, we conducted one FGD, four IDIs, and one FM. This amounted to a total of four FGDs, 16 IDIs, and four FMs in all study sites. The three primary activities of data collection were supplemented with participant observations, which author DT documented as field notes when she joined various activities under the SLIM trial and its associated social-science study. Data collection was conducted in Bahasa Indonesian by author DT, with support of a local Kodi language speaker. The community engagement activities with children were conducted by two local volunteers (teachers) in Kodi language. The engagement activities with adults were conducted in both Indonesian and Kodi. Data analysis We transcribed all FGDs, IDIs and FMs, making them available as 24 transcripts. We then uploaded the transcripts onto NVivo for thematic analysis, following the specific guidelines of Braun and Clarke (2006) [ 27 ]. Initial coding was conducted by DT and CD, and triangulated with a third person (MC). After the three researchers agreed on a coding frame, DT coded all transcripts in Bahasa, and translated a set of illustrative quotes into English. Codes were organized into themes based on the guides prepared for FGDs, IDIs and FMs, with sub-themes added as they emerged. Card-sorting data from the FGDs was captured by photographing the sorted lists, transferred to a spreadsheet, and analysed using Microsoft Excel. Participant observations, in the form of field notes, were discussed among DT, CD and MC, as well as with the wider social-science and trial teams. They were used to verify and extend the analysis already conducted from FGD, IDI and FM data. Ethics declaration SLIM’s human-study protocol covered the current social-science study and received approval from the ethics committees of the Medical and Health Research Ethics Committee, Faculty of Medicine, Public Health and Nursing, University of Gadjah Mada (KE/FK/0773/EC), Indonesian National Research and Innovation Agency (BRIN) (023/KE.02/SK/8/2022), and the Oxford University Tropical Research Ethics Committee (556−21). Local permission was granted by the government of Southwest Sumba District; the governments of Kodi Balaghar and Kodi Bangedo Sub-Districts; and community leaders of Pandawawi, Matakapore, Waimakaha, and Wainyapu Villages. All FGD, IDI and FM participants provided written consent. Results This section summarizes our analyses of FGD, IDI, FM and participation-observation data. Results are organized into six domains: (1) Participants characteristics, (2) Common health problems, (3) Villagers experiences and views of malaria, (4) Community perceptions of ITL, (5) Community perceptions of ivermectin MDA, and (6) Possible barriers to malaria research. Participants characteristics Our community engagement events attracted an estimated 650 participants. Over 40% of them were school children, while the rest were adults. Our data-collection activities enrolled 75 participants, including 59 who joined FGDs and FMs (the same individuals were invited first for FGDs and again for FMs), and 16 who answered IDIs. People contributing to the current social-science study were a mix of those who directly participated in the SLIM trial (having their livestock receive ivermectin or serve as a control), and those who only knew about the trial. Participation in the social-science study was spread rather evenly among Pandawawi, Matakapore, Waimakaha and Wainyapu Villages, each contributing 14–22 participants. In terms of village roles, the stakeholders included government officials, community leaders, livestock owners, and health cadres, the latter of whom constituted the largest group (23 participants). With regard to gender, 32 participants (less than half) were female. Table 1 provides details of the participants’ characteristics. View this table: View inline View popup Download powerpoint Table 1. Participants characteristics Common health problems All 59 FGD participants undertook card sorting. However, 54 of them worked in pairs and 5 participated as individuals, thus producing a total of 32 responses. Each response was a set of 12 cards representing 12 common health problems on Sumba (as suggested by local healthcare professionals). When a health problem was identified by a pair/individual as the most important, it received a score of 12. Less important problems received scores lower than 12. The least important health problem was coded as 1. We organized all 32 responses in a spreadsheet (see Supplementary Material ) and aggregated the score for every health problem investigated at the FGDs. Table 2 is the full list of 12 common health problems on Sumba and their associated ranking by the study participants. View this table: View inline View popup Download powerpoint Table 2. Common health problems on Sumba ranked by study participants Collectively FGD participants identified malaria as the number one disease troubling Kodi residents. Malaria’s score was 332, which was 42% higher than the score given to influenza, the second-most important health problem on the list. Malaria was considered three times as important as Covid-19, which FGD participants deemed to be the least concerning in 2022–2023. These rankings show that malaria remained a top concern on Sumba, and its importance surpassed other health problems by a wide margin. Villagers experiences and views of malaria All 75 individuals who formally contributed data at FGDs, IDIs and FMs were familiar with malaria. Either they had contracted malaria before, or knew someone afflicted by this disease. Having multiple malaria cases in the same family was not rare. A woman mentioned that almost all of her children had had malaria, including her twins and youngest child. The vast majority of participants were able to name malaria symptoms, including most commonly fever, dizziness, and body ache. Many villagers were aware of mosquitoes as transmitting malaria. Some were quite specific when they named Anopheles as a vector, pointing out that their population tended to surge around the end of each year, or the beginning of Sumba’s rainy season. As for treatment, we did not observe any dominant pattern among the participants. Villagers’ stories seemed equally split between early treatment and delay in healthcare seeking. Those who were quick to seek medical attention reported going to community health centers (government-run) or local clinics (privately-operated). Those who delayed seeking formal medical care reported trying to control disease symptoms themselves, by taking medications (e.g. paracetamol) or home remedies (e.g. mahogany seeds and papaya leaves). One participant brought up the case of a mother who took her son to the community center when he was already having convulsions. The boy tested positive for malaria and showed complications for several diseases. His case was so severe that the center’s staff referred him to a hospital in Southwest Sumba District. Overall, the participating villagers appeared confident with their own knowledge of malaria, as well as good community awareness of the disease. They attributed such awareness to the health-promotion efforts of a wide range of entities, such as community health centers, Perdhaki (the Association of Voluntary Health Services of Indonesia) and local health NGOs. Community perceptions of ivermectin and ivermectin treated livestock (ITL) Perceptions of ivermectin and ITL were sought from 75 participants of FGDs, IDIs and FMs. These conversations were had when the SLIM trial was taking place in their communities, so the comments they made applied specifically to SLIM, rather than a hypothetical intervention treating animals with ivermectin to control human malaria. Some animal owners recalled feeling skeptical at first, for they feared that injecting cows and buffaloes when they were not sick would cause harm to the livestock themselves. However, they decided to have their livestock enrolled in SLIM partly because the research staff explained all trial procedures to be safe, and mostly because there was a government veterinarian from Southwest Sumba present on the team. Further into the trial, many community members, even those who did not have animals enrolled, came to appreciate SLIM’s working approach. Without making a distinction between the SLIM trial and its associated social-science study, they described communication from the researchers as simple, regular, and respectful. A woman compared SLIM with a previous malaria study she had experienced, and observed the SLIM trial to be more positive for her community: “I think that when this team did the research, you have taken a friendlier approach all this time. Very respectful of culture in terms of your work and attitude, conveying information to us for the whole study time. The community understands this research and I am sure that the community supports this. You know how to provide information to them so that they can easily understand, especially the information before the study” (Participant from IDI01V02). Showing their acceptance of the trial, community members provided both material support and specific advice to help the research team operate trial activities. For example, some villagers contributed bamboo to install net traps for collecting mosquitoes that landed on SLIM livestock. In Pandawawi village, many locals were involved in the set-up of a net trap, advising researchers to place it further away from the sacred tree of their community. A significant part of Kodi’s population practice Marapu, a belief system indigenous to Sumba, designating certain trees and megalithic structures as sacred. Placing research instruments such as SLIM’s net traps close to these sacred entities would have been considered culturally inappropriate. Community members also expressed satisfaction from the intended trial outcome, i.e. mosquitoes dying after they blood fed on ivermectin-treated animals. Several IDI participants communicated a sense of pride, seeing that they could contribute to science and help with malaria control in their communities. One woman went as far as to register her willingness to participate in future ITL projects. “I support this research. I also have a younger sibling whose animals are used in this research, including a buffalo and a cow. I am proud of him because he wants to help. If I have an animal that can be used, I will give it for the research. Hopefully, there will be more research in the future, and if I can get involved, I will help too. Which is important for our health in the village” (Participant from IDI03V04). Community perceptions of ivermectin mass drug administration (MDA) To understand perceptions surrounding the use of ivermectin MDA in humans, we spoke with the same 75 individuals who had shared their thoughts on ITL. The difference was that they could only comment on MDA in a hypothetical sense, whereas what they had communicated about ITL was tied to SLIM, a trial happening in their own villages. Although we asked generally about possible MDA to control malaria, several FGD participants assumed that the same SLIM trial team would expand into MDA and treat Sumba residents with ivermectin. Given their positive experience with SLIM, the participants were willing to support MDA interventions. “If there are more, we already know you and the team, we have already participated, so I think that is fine, we can still support you” (Participant from FGD02V01). But the trust implied above was far from being unconditional. Instead, most participants of the FGDs, IDIs and FMs exercised caution when they said MDA (and any new research projects) would need to seek permission from local health authorities. Ivermectin currently has limited approval as human drug in Indonesia, and thus people on Sumba are unlikely to have had past experience with this medication. Finally, some FGD participants held a special reservation over who should serve as a target for MDA. Three people in Wainyapu Village emphasized that they would accept ivermectin for themselves, but not children. “Let me try it. Do not go to the children. I am afraid they may get drunk on drugs” (Participant from FGD01V04). Possible barriers to malaria research Our social-science study, alongside the SLIM trial, approached six villages but ended up conducting fieldwork in four. We withdrew from two villages: The first one had its mosquito habitat damaged following heavy rains. The second featured an environment suitable for SLIM trial procedures, but researchers from both the trial and social-science sides felt that collectively speaking, the community was unwilling to participate. The community in the second village posed some barriers to not only SLIM, but also malaria research more generally. The first issue raised was regarding the level of compensation offered. At first, several livestock owners in this village agreed to the standard rate with which SLIM would compensate its trial participants. Later, they said the compensation would need to be higher and refused their animals. People who had promised to look after the livestock enrolled in the study also suddenly refused to do so. In screening livestock for potential inclusion in the SLIM trial it was discovered that several buffalo had Surra (Trypanosomiasis) which is a particularly devastating disease for horses, which have great cultural significance on Sumba. As this village was outside of the Kodi subdistrict, the study team collaborated with government health veterinarians that spoke the local Gaura language, and offered free diagnosis and treatment for this devastating disease, which was still refused by some livestock owners. Furthermore, there were informal reports about a buffalo that had died although the SLIM trial had not injected any livestock in the village. We aimed to investigate the root cause of this increasingly unwelcome atmosphere, but could not find any villagers in Gaura subdistrict open enough to explain the real situation. However, we later gathered that there had been a conflict between different neighborhoods within the village, specifically the residents closest to the mosquito habitat that SLIM trial wanted to work in. Such lack of social cohesion seemed to be a contributing factor as to why the research permission given by community leaders did not represent strong collective consent from the village. Discussion In congruence with official statistics [ 2 ], Sumba residents confirmed that malaria was a very common disease, and it remained a top concern on the island. To address this important health problem, participants of the current social-science study expressed a nuanced acceptance of ivermectin for malaria control. Community members maintained that interventions in the forms of ITL for animals and MDA for humans should have the right hosts (livestock and adults, instead of children), the right approval from a respected health authority, and the right expertise for functioning in the field (e.g. veterinarians and doctors). These insights were valuable and yet unsurprising, given that they constitute the basic elements of research protocols anywhere in the world. What seemed novel from the research on Sumba was that many participants articulated the need for simple, regular, and respectful communication, and in the case of one particular village, we observed a lack of social cohesion as possibly hindering trial activities. On communication, we believe that community members appreciated the working approach taken by SLIM’s trial and social-science researchers, which in turn triggered active contribution on the part of Kodi residents. This reality contrasts the current literature, which tends to portray the islanders in a negative light. In government accounts, ordinary Sumbanese are oftentimes seen as passive recipients of assistance (e.g. mosquito nets) [ 28 ]. Guntur et al (2021 and 2022) report poor malaria knowledge on Sumba and attribute it to low levels of education [ 29 , 30 ]. Mariana and Martha (2024) also follow the knowledge deficit model, highlighting Sumbanese women’s superstitious beliefs about malaria [ 31 ]. A 2024 report commissioned by UNICEF depicts an attitude of complacency among island residents, who find it hard to grasp scientific ideas such as asymptomatic malaria [ 32 ]. These findings may be factually correct, and we acknowledge poverty as well as limited educational opportunities on Sumba [ 17 , 18 ], however, it does not necessarily follow that interventions have to focus on the ‘knowledge gap’ by giving out material support or fixing the knowledge of local people. What we came to realize in 2022–2023 was that Kodi residents knew sufficiently about malaria so that when SLIM researchers communicated with simplicity, regularity and respect, community members reciprocated by making an active contribution to research. While this reciprocity may seem instant, it is likely that trust had been built over a long time because two of the SLIM partners had researched malaria on Sumba since as early as 2001 (Sumba Foundation) [ 33 ] and 2010 (Oxford University Clinical Research Unit) [ 34 – 39 ]. The Sumba Foundation partners were well known and trusted for their healthcare clinics and social projects. An interviewee implied that her community did not want to contribute previously when there had been a different malaria trial that was unfriendly and treated research as a one-off event. The good communication and trust that the SLIM team had demonstrated, i.e. simple, regular and respectful, should therefore be taken up in malaria research as a tool for motivating active contribution from community members, regardless of the economic and educational settings they find themselves in. On lack of social cohesion, there is a history of animosity on Sumba, which is not along religious or ethnic lines, but which tends to be clan-based [ 40 ]. Legal scholar Jacqueline Vel argues that in certain parts of the island, there is hardly a single leader that unifies all community members. Different factions in the government may rely on their respective clans to fight each other, and vice versa [ 40 ]. The implication of this tradition is that when a trial has obtained approvals from all levels of government, and yet there is an internal conflict between different government leaders or different clans, one side may block research cooperation if they perceive the research to be beneficial for the other side only. Such a situation is not rare for studies in low- and middle-income countries [ 41 ]. Vincent et al’s (2022) review of community engagement with malaria research recommends that where social cohesion is lacking, scientists should seek out a diversity of stakeholders and engage them using a different method appropriate for each group [ 41 ]. We agree with the solution proposed by Vincent et al (2022), and would add that in a fragmented community, research staff may do well by preceding trial activities with inclusive engagement over a long period of time. For SLIM, our plan was to do social science alongside the primary trial. If we had scheduled the collection of qualitative data and organization of community events as an extended lead time before trial activities, we might have uncovered ways to work with different community segments and conduct the SLIM trial in the village with low social cohesion. The current paper has its strength and limitations. Our study was best at combining traditional methods (FGDs, IDIs, FMs, and participant observations) and active listening at the population level through a series of community-engagement events. We were thus able to capture the nuances surrounding community acceptance of ivermectin for malaria control. On the other hand, our study had two limitations. First, some FGDs were too large. While standard research guidelines recommend a maximum of 12 participants/discussion [ 42 ], we conducted three FGDs that included 14–18 participants. Our plan was to have 10 participants/FGD, but some villagers came uninvited and we thought it would be against the spirit of community engagement to send them away. We still managed to learn meaningful insights from the large FGDs by having two facilitators for every discussion, where they took turns to ensure that all participants could express themselves freely without feeling left-out. Second, we had a total of 75 people contributing data, a sample probably too small to represent the entire village populations. However, complementary to this modest sample, our community-engagement events reached about 650 people, which was approximately 11% the combined population of Kahale, Matakapore, Waimakaha, and Wainyapu where the SLIM trial was implemented. If there had been views about ITL and ivermectin MDA that were contrary to the formal qualitative data, we might have recognized them at these community-engagement events. As Indonesia is determined to eliminate malaria by 2030 and there remain several parts of the country that experience a high prevalence, there must be new tools to control this disease. Two of the novel strategies currently available include mass ITL and the SLIM trial has been published [ 14 ], and MDA for humans (which is being tested in two districts of Papua Province [ 43 ]). We recommend more research into ITL and MDA as important approaches to control malaria in Indonesia, and that research trials take a systematic approach to communicating simply, regularly, and respectfully with community members for maximum acceptance. We further add to the malaria literature that in areas of low social cohesion, researchers should engage a diversity of community segments and sustain engagement over an extended period of time before implementing trial activities. Data Availability Data is available through request to the Oxford University Clinical Research Unit data sharing committee Supplementary Material Acknowledgements We acknowledge the partnership of SLIM participants, the wider communities and community leaders in Kahale, Matakapore, Waimakaha and Wainyapu Villages in Southwest Sumba. We acknowledge the support of local government in Kodi District and Southwest Sumba. 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Share Community perceptions and acceptance of ivermectin for malaria control on Sumba Island, Indonesia Diana Timoria , Christa Dewi , Claus Bøgh , Tri Baskoro , Wisnu Nurcahyo , Vincentius Arca Testamenti , Giao Vu Thi Quynh , Lorenz von Seidlein , Kevin Kobylinski , Mary Chambers medRxiv 2025.06.04.25329015; doi: https://doi.org/10.1101/2025.06.04.25329015 Share This Article: Copy Citation Tools Community perceptions and acceptance of ivermectin for malaria control on Sumba Island, Indonesia Diana Timoria , Christa Dewi , Claus Bøgh , Tri Baskoro , Wisnu Nurcahyo , Vincentius Arca Testamenti , Giao Vu Thi Quynh , Lorenz von Seidlein , Kevin Kobylinski , Mary Chambers medRxiv 2025.06.04.25329015; doi: https://doi.org/10.1101/2025.06.04.25329015 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Area Infectious Diseases (except HIV/AIDS) Subject Areas All Articles Addiction Medicine (568) Allergy and Immunology (863) Anesthesia (299) Cardiovascular Medicine (4425) Dentistry and Oral Medicine (443) Dermatology (382) Emergency Medicine (607) Endocrinology (including Diabetes Mellitus and Metabolic Disease) (1507) Epidemiology (15221) Forensic Medicine (30) Gastroenterology (1123) Genetic and Genomic Medicine (6588) Geriatric Medicine (667) Health Economics (997) Health Informatics (4524) Health Policy (1368) Health Systems and Quality Improvement (1612) Hematology (540) HIV/AIDS (1264) Infectious Diseases (except HIV/AIDS) (15910) Intensive Care and Critical Care Medicine (1103) Medical Education (623) Medical Ethics (145) Nephrology (667) Neurology (6588) Nursing (346) Nutrition (998) Obstetrics and Gynecology (1143) Occupational and Environmental Health (956) Oncology (3331) Ophthalmology (971) Orthopedics (369) Otolaryngology (420) Pain Medicine (435) Palliative Medicine (129) Pathology (663) Pediatrics (1690) Pharmacology and Therapeutics (691) Primary Care Research (710) Psychiatry and Clinical Psychology (5440) Public and Global Health (9220) Radiology and Imaging (2195) Rehabilitation Medicine and Physical Therapy (1369) Respiratory Medicine (1196) Rheumatology (593) Sexual and Reproductive Health (710) Sports Medicine (529) Surgery (710) Toxicology (99) Transplantation (289) Urology (265) (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'9ffe0aab9ba158d3',t:'MTc3OTQ3NjE5NQ=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();