Low BVDV Antigen Prevalence in Dairy Cattle in the Emirate of Abu Dhabi, UAE: A Cross-Sectional Study with Regional Comparison

Low BVDV Antigen Prevalence in Dairy Cattle in the Emirate of Abu Dhabi, UAE: A Cross-Sectional Study with Regional Comparison | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (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],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Low BVDV Antigen Prevalence in Dairy Cattle in the Emirate of Abu Dhabi, UAE: A Cross-Sectional Study with Regional Comparison Robert BARIGYE, Nabeeha A. Hassan, Asha A. Antony, Shamma A.R Al-Ghaithi, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9242329/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Bovine viral diarrhoea virus (BVDV) is a globally significant pathogen of cattle, causing substantial economic losses through reproductive failure, immunosuppression, and reduced productivity. This cross-sectional study estimated animal- and herd-level prevalence of BVDV antigen in commercial dairy herds in the Emirate of Abu Dhabi (EAD), UAE, and contextualized the findings within the epidemiological landscape of the Middle East and North Africa (MENA) region. A total of 681 cattle from nine large-scale dairy farms were sampled using a stratified systematic approach and tested for BVDV antigen using a commercial antigen-capture ELISA. Apparent animal-level prevalence was 1.02% (7/681; 95% CI: 0.27–1.79%), while herd-level prevalence was 33.3% (3/9 farms). Within-herd prevalence ranged from 0% to 9.1%, with most farms (6/9) showing no antigen-positive animals. Comparative analysis with published regional data indicates that BVDV antigen prevalence in EAD dairy herds is substantially lower than estimates reported in several MENA countries, where both antigen detection and seroprevalence studies suggest more widespread viral circulation. The observed epidemiological pattern, characterized by low animal-level prevalence but presence across multiple herds, is consistent with limited viral circulation, potentially reflecting an early-endemic or partially controlled state. However, as antigen detection identifies current infection but does not distinguish transient from persistent infection, follow-up testing is required to confirm persistently infected animals. These findings provide the first baseline evidence of BVDV infection in UAE dairy cattle and support the implementation of risk-based control strategies, including targeted detection and removal of persistently infected animals, strengthened biosecurity, and strategic vaccination informed by regional epidemiology. BVDV antigen prevalence dairy cattle Emirate of Abu Dhabi MENA Region United Arab Emirates Introduction Bovine viral diarrhoea virus (BVDV) is one of the most economically important infectious pathogens affecting cattle worldwide. The virus, which is a member of the genus Pestivirus within the family Flaviviridae , is associated with reproductive failure, immunosuppression, reduced milk yield, and increased susceptibility to secondary infections. A defining epidemiological feature of BVDV infection is the generation of persistently infected (PI) animals that result from in utero exposure to non-cytopathic virus strains during early gestation (Tautz et al., 2015 ). The PI animals are immunotolerant, shed large quantities of virus throughout life and constitute the principal reservoir sustaining herd-level transmission (Lindberg and Houe, 2005 ). Consequently, the presence of even a small number of PI animals can maintain endemic infection within intensively managed dairy systems. Over the past two decades, several European countries have implemented structured BVDV control and eradication programmes based on systematic surveillance, identification and removal of PI animals, movement control and enhanced biosecurity (Lindberg and Houe, 2005 ). These programmes have demonstrated that early epidemiological characterization is critical for designing proportionate and cost-effective BVD control strategies. In contrast, epidemiological data from many rapidly developing dairy sectors, including those in the Middle East, and the United Arab Emirates (UAE) in particular, remain limited. The UAE has a relatively young but rapidly expanding commercial dairy industry, developed as part of a national food security strategy. Currently, there are 21 commercial dairy farms across the UAE, housing approximately 67,000 cattle (Personal communication, ADAFSA, 2025). Sixteen of these farms are located within the Emirate of Abu Dhabi (EAD), with the largest concentration in the Al Ain region. Dairy production systems in the country are characterized by intensive management, high stocking densities and reliance on imported feed resources. Importantly, foundation breeding stock was historically sourced from countries where BVDV is endemic, including several European nations, North America, Australia and South Africa. International movement of cattle is a recognised risk factor for introduction and dissemination of BVDV (Lindberg and Houe, 2005 ), suggesting that the UAE dairy sector may be vulnerable to viral establishment. Most commercial dairy farms in EAD routinely vaccinate their cattle against BVDV. However, the true epidemiological status of the virus within the regional cattle population remains uncertain. Anecdotal observations from field veterinarians have suggested possible ongoing viral circulation, yet such impressions have not been substantiated by systematically generated prevalence data. In the absence of structured surveillance and published epidemiological evidence, it is not possible to determine whether BVDV actually exists in the country and if it does whether the infections are increasing, stable or declining within the commercial dairy sector. Furthermore, vaccines currently administered in the region are not selected based on documented circulation of specific BVDV genotypes or biotypes within the UAE cattle population. This is despite the fact that BVDV exhibits considerable genetic and antigenic diversity (Liu et al., 2009 ; Yeşilbağ et al., 2017 ), and mismatches between vaccine and field virus strains may compromise vaccine-induced protective immunity. Without baseline epidemiological and virological characterization, the strategic rationale underpinning vaccination programmes cannot be critically evaluated. Notably, in low-prevalence or early-endemic settings, vaccination alone without concurrent identification and removal of PI animals may be insufficient to interrupt transmission (Lindberg and Houe, 2005 ). Taken together, the above factors highlight a critical knowledge gap in the epidemiology of BVDV within the UAE dairy cattle sector. Structured, evidence-based surveillance is required to establish the current burden and distribution of infection and to inform proportionate preventive strategies. Against the above background, the aim of this study was to determine baseline animal- and herd-level BVDV antigen prevalence in commercial dairy cattle in the EAD and to contextualize the findings within the regional epidemiological literature. The study results are intended to inform development of an integrated, risk-based BVD control strategy aligning vaccination, biosecurity, and targeted PI detection with the local epidemiological context. The baseline data will also guide future molecular epidemiological investigations needed to support vaccine–field BVDV strain matching. Materials and Methods 2.1 Study design and sampling strategy A cross-sectional study design was employed to investigate BVDV prevalence, with the sampling frame comprising all registered commercial dairy farms in the Emirate of Abu Dhabi (EAD), UAE at the time of study implementation. Nine farms consented to participate, representing the majority of large-scale commercial dairy operations in the region. Within each farm, animals were selected using systematic random sampling from available herd lists. Sampling was designed to proportionally represent major production groups, including lactating cows, dry cows, and replacement heifers. The sample size required to estimate prevalence under simple random sampling was calculated using the standard formula: where Z = 1.96Z = 1.96Z = 1.96 (95% confidence level), P = 0.01P = 0.01P = 0.01 (expected prevalence), and d = 0.005d = 0.005d = 0.005 (absolute precision). This yielded a theoretical minimum sample size of approximately 1,521 animals. However, due to logistical and operational constraints, a total of 681 animals were sampled. Although lower than the theoretical requirement, the achieved sample size was sufficient to detect low-prevalence infection and provide baseline estimates of BVDV antigen in the study cattle population. Furthermore, given that cattle were clustered within farms, potential intra-herd correlation was accounted for. The design effect (DEFF) was estimated using: DEFF = 1+(m − 1)×ICC where “m” represents the average cluster size and “ICC” the intra-cluster correlation coefficient. Assuming an average cluster size of approximately 66 animals and an ICC of 0.05, consistent with published estimates for infectious disease clustering, the design effect was approximately 4.25. This corresponded to an effective sample size of approximately 203 animals after adjustment for clustering. 2.2. Ethical Approval and Sample Collection Before blood collections, this research was approved by the United Arab Emirates Animal Research Ethics Committee (Application No: ERA_2025_7604, titled: Molecular Epidemiology and Prevalence of Bovine Viral Diarrhoea Virus in Dairy Cattle Herds in The Al Ain Region) with Certificate # ERA_2025_7604 issued on the 28th August, 2025. Vacutainer tubes with a clotting activator were used to collect jugular blood from study cattle and thereafter the samples transported to the laboratory in a cool box. At the laboratory, the blood samples were allowed to clot overnight at 4°C in the refrigerator and the serum separated by centrifugation the following day. Serum samples were stored at -80°C until testing. 2.3 BVDV Antigen Capture ELISA Individual serum samples were tested for BVDV antigen using a commercial antigen-capture ELISA (IDEXX BVDV Ag/Serum Plus Test, IDEXX Laboratories Inc., Westbrook, ME, USA), in accordance with the manufacturer’s instructions. The assay is intended for use with bovine serum and other individual sample types and was performed on serum collected from each animal. Briefly, serum specimens together with assay controls were dispensed into antibody-coated microplate wells to permit capture of BVDV antigen. Following incubation and washing to remove unbound material, an enzyme-conjugated detection secondary antibody was applied, and color development was achieved using the supplied chromogenic substrate. The reaction was terminated with stop solution, and the plates were read at 450 nm using spectrophotometer (Multiskan Sky Thermo Scientific, Singapore). The OD 450 reading for the samples were interpreted based on the sample-to-positive (S/P) ratio or threshold criteria provided in the kit protocol. Samples exceeding the manufacturer-defined cut-off value were considered positive for BVDV antigen. Quality control was ensured through inclusion of kit-provided positive and negative controls in each assay run, and test validity was confirmed according to manufacturer acceptance criteria (IDEXX Laboratories Inc., Westbrook, ME, USA). 2.4 Regional Epidemiological Literature Review and Contextual Analysis To contextualize the prevalence estimates generated in this study, a structured narrative review of published literature on BVDV epidemiology in the Middle East and neighboring regions was undertaken. Peer-reviewed articles were identified through electronic database searches (e.g., PubMed, Scopus and Web of Science) using combinations of keywords including “BVDV,” “bovine viral diarrhoea,” “prevalence,” “seroprevalence,” “antigen,” “PI,” and country names within West Asia and North Africa. Studies reporting animal-level or herd-level prevalence in dairy cattle populations were prioritized yielding eight papers that met the inclusion criteria. Both antigen detection and serological investigations were considered to allow interpretation of active infection and cumulative exposure patterns. Extracted information included country, study population, diagnostic method, sample size and reported prevalence (Table 2). Findings from these regional studies were used descriptively to frame and interpret the UAE prevalence data within a broader epidemiological context. 2.5 Statistical data analysis Animal-level apparent prevalence was calculated as the proportion of antigen-positive animals among the total number tested. Exact binomial (Clopper–Pearson) 95% confidence intervals were computed to account for the low number of positive outcomes. Herd-level prevalence was defined as the proportion of farms with at least one antigen-positive animal, and farm-level prevalence estimates were calculated with corresponding exact confidence intervals. Given the small number of positive observations, multivariable modelling was not performed. Statistical comparisons between selected farms were conducted using Fisher’s exact test. All statistical analyses were performed using standard epidemiological methods consistent with preventive veterinary research practice. Prevalence estimates were calculated as unweighted proportions. Confidence intervals were not adjusted for clustering and may therefore underestimate uncertainty; results should be interpreted accordingly. Results A total of 681 cattle were tested, of which 7 were positive for BVDV antigen, yielding an overall apparent prevalence of 1.02% (95% CI: 0.27–1.79%) (Table 1 ). In addition, BVDV antigen-positive animals were detected in 3 of 9 farms giving a herd prevalence of 33.3% and farm-level prevalence of BVDV antigen ranged from 0% to 9.1%, with the highest prevalence observed in Farm 13 (3/33). However, most farms (6/9) had no detectable antigen-positive animals. Furthermore, lower within-herd prevalence estimates were observed in larger herds (e.g., Farms 7 and 11), whereas higher apparent prevalence and greater variability were observed in smaller sampled groups, reflecting the influence of sample size on precision. Table 1 summarizes the number of cattle tested per farm using BVDV antigen-capture ELISA, together with the number of antigen-positive and antigen-negative animals and the corresponding apparent prevalence. Table 1 Farm-level results of BVDV antigen detection in commercial dairy herds in the Emirate of Abu Dhabi. Farm Total cattle population at study farm Planned sample size Actual number of samples tested by antigen Capture ELISA Positive for BVDV antigen Negative for BVDV antigen BVDV Antigen Prevalence (%) Farm 1 861 25 25 0 25 0.0 Farm 2 182 5 5 0 5 0.0 Farm 4 1050 31 31 0 31 0.0 Farm 6 292 9 9 0 9 0.0 Farm 7 3372 98 298 2 296 0.7 Farm 9 832 24 24 0 24 0.0 Farm 10 280 8 8 0 8 0.0 Farm 11 1641 48 248 2 246 0.8 Farm 13 1126 33 33 3 30 9.1 TOTALS 9,636 281 681 7 674 1.02 Table 1 above summarizes farm-level detection of bovine viral diarrhoea virus (BVDV) antigen in commercial dairy cattle herds in the Emirate of Abu Dhabi, United Arab Emirates. The table presents the total herd size, number of animals tested by antigen-capture ELISA, number of antigen-positive and antigen-negative animals, and the corresponding apparent prevalence for each farm. Country / region Population & diagnostic method Animal-level prevalence Herd-level prevalence Key reference(s) UAE (Emirate of Abu Dhabi) Commercial dairy cattle, Ag-ELISA (current study) 1.02% antigen prevalence 33.3% antigen prevalence Meta-analytic summary of the present UAE study data Jordan 62 non-vaccinated dairy herds (671 cows), indirect ELISA (antibody detection) 31.6% true seroprevalence 80.7% true herd seroprevalence Talafha et al. ( 2009 ) Iran (national) Multiple studies, various dairy systems, antibody ELISA & virus neutralization test 52% pooled seroprevalence (95% CI 40.1–63.9) – Jokar et al. ( 2021 ) Iran (central desert) 800 cows in 76 dairy herds, indirect ELISA 66.8% seroprevalence 91.6% herd-level seropositivity Karimi et al. ( 2022 ) Turkey (Aegean Region) 552 cows in 48 unvaccinated dairy herds, indirect ELISA 48.4% seropositivity 89.6% herd-level prevalence İnce & Ayaz ( 2023 ). Egypt Dairy herds, Indirect ELISA (compiled) 40.0% seroprevalence – Selim et al. ( 2018 ) Iraq Dairy cattle, Ag-ELISA (compiled), RT-PCR 5.46% antigen prevalence; 13.96% by RT-PCR – Hasan and AlSaad, ( 2018 ) Iraq Ag-ELISA; Indirect ELISA 7.1% antigen; 23.57% antibody – Jarulla et al. (2012) Saudi Arabia Cattle, Ag-ELISA, indirect ELISA, RT-PCR 14.0% seroprevalence (RNA detected in 12.0% of the cattle) Al-Mubarak et al. ( 2023 ) Table 2. Reported BVDV prevalence in dairy cattle in selected Middle Eastern countries and comparison with findings from the Emirate of Abu Dhabi, UAE. Seroprevalence estimates reflect cumulative exposure and are not directly comparable to antigen-based estimates of active infection. Presented in Table 2 is a summary of published animal- and herd-level BVDV prevalence estimates from selected Middle Eastern countries, including serological (antibody-based) and antigen and BVDV nucleic acid detection studies, alongside the present BVDV survey in the EAD. Differences in diagnostic methods (Ag-ELISA vs. antibody ELISA or virus neutralization), study populations, management systems and vaccination status should be considered when interpreting cross-country comparisons. The table contextualizes the relatively low antigen prevalence observed in the EAD within the broader regional epidemiological landscape. In respect to Table 2, it should be noted that seroprevalence estimates derived from the regional literature reflect cumulative exposure and are not directly comparable to antigen-based estimates of active infection. Discussion To our knowledge, this study provides the first systematically derived estimates of BVDV antigen prevalence in commercial dairy cattle in the EAD in the UAE. At the individual-animal level, antigen prevalence was 1.02%, which is relatively low, yet BVDV-positive cattle were detected in 3 out of 9 (33.3%) herds, indicating that the virus is present but not widely disseminated. This profile, of low animal-level prevalence combined with scattered herd-level infection, is consistent with an early-endemic or controlled scenario in which PI animals occur sporadically and onward transmission is limited (Houe et al., 2006 ; Moennig and Becher, 2018 ). When interpreted against regional data, the present EAD findings sit at the lower end of the spectrum for West Asia and North Africa. A global meta-analysis reported higher PI prevalence in West Asia of > 1.6% than in Europe and Australia (≤ 0.8%), reflecting weaker or absent control programmes in many countries (Scharnböck et al., 2018 ; Al-Mubarak et al., 2023 ). In the Middle East, reported PI prevalence is approximately 1.5% in Egypt and 0.8% in Iraq, with antigen detection by Ag-ELISA around 6.0% in both countries (Al-Mubarak et al., 2023 ), compared to 1.02% detected in dairy cattle from the EAD, UAE in this study. The low BVDV antigen prevalence observed in this study is, therefore, broadly compatible with the antigen (PI animals) prevalence cited for Egypt and Iraq (Al-Mubarak et al., 2023 ). In contrast, however, serological surveys from geographically nearby countries to the UAE indicate substantial historical exposure to BVDV. A systematic review and meta-analysis from Iran estimated a pooled seroprevalence of 52.0% (95% CI 40.1–63.9) across cattle populations (Jokar et al., 2021 ), with more recent work in the central desert of Iran reporting animal-level seroprevalence of 66.8% and herd-level seropositivity of 91.6% in intensively managed Holstein-Friesian herds (Karimi et al., 2022 ). In Jordan, Talafha et al. ( 2009 ) reported true seroprevalence estimates of 31.6% at animal level and 80.7% at herd level in non-vaccinated dairy herds, again suggesting long-standing endemic circulation under semi-intensive management. In Iraq, BVDV antigen prevalence has been reported at 7.1% (Jarullah et al., 2012 ) and 5.4% (Hasan and AlSaad, 2018 ). In the Aegean Region of Turkey, on the other hand, animal-level seropositivity of 48.4% and herd-level prevalence of 89.6% were recently documented in unvaccinated dairy herds (Ince and Ayaz, 2023). Together, these data emphasize that the EAD dairy sector may currently be experiencing a relatively favourable epidemiological situation compared with other regional dairy industries, despite broadly similar climatic constraints and heavy reliance on imported genetics. The divergence between the low antigen prevalence reported here and the moderate-to-high seroprevalence documented in neighbouring Middle Eastern countries also highlights the importance of distinguishing active infection from cumulative exposure. Serology captures both past and present infection, whereas antigen detection and virus isolation primarily reflect current viraemia and the presence of PI animals (Houe, 1995 ; Jokar et al., 2021 ). In contexts where effective control measures or partial immunity have been established, it is epidemiologically plausible to observe high antibody prevalence with low concurrent antigen detection (Moennig and Becher, 2018 ). Conversely, in completely naïve herds, low seroprevalence and low antigen prevalence might both be expected. Without paired antibody data, the present study cannot fully resolve which of these scenarios best describes the EAD herds; however, continuous vaccination reported by most farms and the historical importation of cattle from BVD-endemic regions suggest that some degree of previous exposure is likely. From a quantitative epidemiology standpoint, the cluster-sampled design and explicit accounting for intra-herd correlation strengthen the inference compared with naïve binomial approaches. Adjustment for clustering reduces the effective sample size and widens confidence intervals, acknowledging that animals within the same herd share exposures and infection status is not independent (McDermott and Schukken, 1994 ; Dohoo et al., 2009 ). In this study, the design effect implied that point estimates of BVDV antigen prevalence, although low, were somewhat imprecise; thus, while widespread infection can be confidently ruled out, small, localized clusters of higher prevalence cannot be excluded. Furthermore, as confidence intervals were not adjusted for clustering, the reported uncertainty may be underestimated and should be interpreted with caution. This uncertainty underlines the importance of repeated cross-sectional surveys or longitudinal monitoring to detect temporal trends, particularly in a rapidly evolving production system. The low number of antigen-positive animals must also be interpreted in light of diagnostic performance. Ag-ELISA is widely used for BVDV antigen detection, with good sensitivity and specificity in serum and tissue samples (Hanon et al., 2017 ; Hanon et al., 2018 ). However, in very low-prevalence settings, even small imperfections in test performance can materially affect predictive values and apparent prevalence (Scharnböck et al., 2018 ). Where vaccination is intensive, transient viraemia in recently vaccinated animals, interference from maternal antibodies in young calves, or sample handling constraints may further complicate interpretation (Hanon et al., 2017 ; Moennig and Becher, 2018 ). These considerations argue for confirmatory testing of BVDV antigen positive cattle using RT-PCR as well as re-sampling those animals for PI classification. Ideally, complementary serology and bulk-tank milk surveillance would be required to characterize true BVDV infection status at herd level (Hanon et al., 2018 ; Guelbenzu-Gonzalo et al., 2021 ). The management context in the EAD, UAE is also highly relevant to understanding observed patterns. Farms in this survey represented large, intensively managed enterprises, with high stocking densities and near-complete dependence on imported feed which in principle are conditions that favour transmission of respiratory and enteric pathogens (Karimi et al., 2022 ). At the same time, these operations tend to have strong veterinary oversight, controlled biosecurity and structured vaccination programmes, in contrast to many smallholder or mixed systems in the region (Talafha et al., 2009 ; Jokar et al., 2021 ). Intensification under tight biosecurity may therefore simultaneously elevate the risk of explosive outbreaks if PI animals are introduced and reduce the probability of sustained endemic circulation if surveillance and removal are effectively implemented (Van Roon et al., 2020 ). Economically, even low prevalences of PI animals can be highly consequential. BVDV is associated with substantial losses through decreased fertility, early embryonic death, abortions, immunosuppression and increased calf morbidity and mortality (Chase, 2013 ). Elsewhere, controlled challenge studies and observational data have shown that PI animals act as strong infection amplifiers within herds, and their presence is consistently identified as a key driver of reproductive and production losses (Grooms, 2004 ; Loneragan and Thomson, 2005; Van Roon et al., 2020 ). In low-prevalence contexts such as the EAD, targeted identification and removal of PI animals, supported by high-quality biosecurity and risk-based surveillance, is generally more cost-effective than blanket vaccination alone (Lindberg and Houe, 2006; Moennig and Becher, 2018 ). Several limitations should be considered when interpreting the present study findings. The cross-sectional design provides a temporal snapshot but cannot distinguish transiently infected from PI animals without follow-up testing (Houe, 1995 ; Al-Mubarak et al., 2023 ). Although the sampling strategy accounted for clustering, logistical constraints limited the number of animals sampled per herd, particularly in some smaller farms, which may have reduced the ability to detect within-herd heterogeneity. Besides, sampling was also restricted to commercial dairy units in the EAD and therefore these data cannot be generalized to the BVDV dynamics in other emirates, beef enterprises or smallholder cattle production systems. The exclusive reliance on BVDV antigen detection precludes inference on past exposure and herd immunity, as no antibody testing was undertaken. Finally, molecular characterization of detected viruses was beyond the scope of this survey; consequently, the circulating genotypes and their relationship to vaccine strains remain unknown, despite evidence from Iran, Turkey and other regions that indicate substantial genetic diversity and genotype-specific patterns of spread exist in the Middle East (Liu et al., 2009 ; Yesilbag et al., 2008; Khezri, 2015 ). These limitations underscore the need for longitudinal monitoring, combined antigen–antibody testing, and molecular epidemiological studies to fully characterize BVDV dynamics in the UAE. Conclusion In summary, this study demonstrates a very low animal-level prevalence of BVDV antigen in commercial dairy cattle in the Emirate of Abu Dhabi, with infection confined to a minority of herds. In the context of the high seroprevalence reported from other Middle Eastern dairy systems and the elevated PI prevalences described in regional meta-analyses, these findings suggest that the UAE dairy sector remains at a relatively favourable stage in the BVDV epidemiological trajectory, where elimination via targeted measures remains feasible. The combination of structured, cluster-aware sampling and farm-level detection of infection provides an important baseline for future surveillance and control efforts. The data obtained in this study support a risk-based control strategy that prioritizes systematic PI detection and removal, rigorous biosecurity, particularly relating to animal movements and replacement stock, and enhanced import screening, with vaccination used strategically and ideally informed by molecular data pertaining to circulating BVDV genotypes. Expanding surveillance to include serology, repeated cross-sectional surveys and broader geographic coverage will be critical to detect temporal changes in BVDV prevalence, refine economic evaluations of alternative control scenarios and guide evidence-based policy decisions for BVD control and potential eradication in the UAE. Declarations Data availability statement The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Funding The research project was financially supported under UPAR Grant No G00004519 by the United Arab Emirates University under a research funding mechanism that promotes mentoring undergraduate students in research. Conflict of interests No potential conflicts of interest are reported by the author(s). Ethics approval statement The research project was approved by the Animal Research Ethics Committee of the United Arab Emirates University (Application No: ERA_2025_7604, titled: Molecular Epidemiology and Prevalence of Bovine Viral Diarrhoea Virus in Dairy Cattle Herds in The Al Ain Region; Certificate # ERA_2025_7604 issued on the 28th August, 2025). Consent for publication Not applicable Authors' contributions Robert Barigye was project Principal Investigator who, along with co-authors Asha Antony, and Gobena Ameni conceptualized and wrote the research proposal, contributed to data analysis and drafting of the manuscript. Nabeeha A. Hassan and Aboma Zewude are research assistants who did the laboratory testing of the blood samples. Last but not least, co-author Shamma A.R. Al-Ghaithi is an undergraduate veterinary student who was mentored and participated in the laboratory testing of samples as a requirement of the UPAR Grant. Acknowledgements All veterinarians and staff at the study dairy farms in the Emirate of Abu Dhabi are acknowledged for helping with the collection of blood samples. The management of those farms is also recognized for permitting the condition of these studies. References Al-Mubarak, A.I.A., Al-Kubati, A.A.G., Skeikh, A., Hussen, J., Kandeel, M., Flemban, B. and Hemida, M.G., 2023. A longitudinal study of bovine viral diarrhea virus in a semi-closed management dairy cattle herd, 2020–2022. Frontiers in Veterinary Science , 10, 1221883. https://doi.org/10.3389/fvets.2023.1221883 Chase, C.C., 2013. The impact of BVDV infection on adaptive immunity. 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Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 29 Apr, 2026 Reviewers invited by journal 29 Apr, 2026 Editor assigned by journal 02 Apr, 2026 First submitted to journal 30 Mar, 2026 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-9242329","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":631762456,"identity":"411412f8-858b-40f9-b411-f3e98040c46a","order_by":0,"name":"Robert BARIGYE","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4UlEQVRIiWNgGAWjYDACCSBOAGJ+0rVINpCkBQQMDhCrw3x287MPD34dljO+kfzwMQ+DnTwD+2H8umXuHDOekdh32NjsRpqxMQ9DsmEDT1oCfndJJBgzJPYcTtx2I8FMmoeBGag8x4CAlvTPIC31m2ekf//Nw1CfwMD//gMBLTnGDAk/DicYSOSYMfMwHE5gkMjBq4NBQuZMMUNiQ7rhjDNviiXnGBw3bJN4RsBh0u2bGX/8sZbnb0/f+OFNRbU8P3/yA/zWgABjWzOUBTSfjbB6EPhTR5y6UTAKRsEoGJkAACWdQdcgs9CsAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-8420-075X","institution":"United Arab Emirates University","correspondingAuthor":true,"prefix":"","firstName":"Robert","middleName":"","lastName":"BARIGYE","suffix":""},{"id":631762457,"identity":"b57a2ece-a705-4218-a9b8-768d4bd2955f","order_by":1,"name":"Nabeeha A. Hassan","email":"","orcid":"","institution":"United Arab Emirates University","correspondingAuthor":false,"prefix":"","firstName":"Nabeeha","middleName":"A.","lastName":"Hassan","suffix":""},{"id":631762458,"identity":"22d20e96-c3eb-4443-90ec-ccc32b8b29f2","order_by":2,"name":"Asha A. Antony","email":"","orcid":"","institution":"United Arab Emirates University","correspondingAuthor":false,"prefix":"","firstName":"Asha","middleName":"A.","lastName":"Antony","suffix":""},{"id":631762459,"identity":"213ca056-fd39-40ce-be62-19884c32898c","order_by":3,"name":"Shamma A.R Al-Ghaithi","email":"","orcid":"","institution":"United Arab Emirates University","correspondingAuthor":false,"prefix":"","firstName":"Shamma","middleName":"A.R","lastName":"Al-Ghaithi","suffix":""},{"id":631762460,"identity":"a6d204ed-9986-4e55-af82-ba9d16068a02","order_by":4,"name":"Aboma Zewude","email":"","orcid":"","institution":"United Arab Emirates University","correspondingAuthor":false,"prefix":"","firstName":"Aboma","middleName":"","lastName":"Zewude","suffix":""},{"id":631762461,"identity":"aac4240c-1e68-4b66-8ee3-fa7a978711e5","order_by":5,"name":"Gobena Ameni","email":"","orcid":"","institution":"United Arab Emirates University","correspondingAuthor":false,"prefix":"","firstName":"Gobena","middleName":"","lastName":"Ameni","suffix":""}],"badges":[],"createdAt":"2026-03-27 08:41:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9242329/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9242329/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108806955,"identity":"52f059f8-962b-47b8-889e-ace89def2ce1","added_by":"auto","created_at":"2026-05-08 15:29:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":298145,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9242329/v1/4bf97b11-d681-4cf2-883c-54cadfa0646f.pdf"}],"financialInterests":"","formattedTitle":"Low BVDV Antigen Prevalence in Dairy Cattle in the Emirate of Abu Dhabi, UAE: A Cross-Sectional Study with Regional Comparison","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBovine viral diarrhoea virus (BVDV) is one of the most economically important infectious pathogens affecting cattle worldwide. The virus, which is a member of the genus Pestivirus within the \u003cem\u003efamily Flaviviridae\u003c/em\u003e, is associated with reproductive failure, immunosuppression, reduced milk yield, and increased susceptibility to secondary infections. A defining epidemiological feature of BVDV infection is the generation of persistently infected (PI) animals that result from \u003cem\u003ein utero\u003c/em\u003e exposure to non-cytopathic virus strains during early gestation (Tautz et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). The PI animals are immunotolerant, shed large quantities of virus throughout life and constitute the principal reservoir sustaining herd-level transmission (Lindberg and Houe, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Consequently, the presence of even a small number of PI animals can maintain endemic infection within intensively managed dairy systems. Over the past two decades, several European countries have implemented structured BVDV control and eradication programmes based on systematic surveillance, identification and removal of PI animals, movement control and enhanced biosecurity (Lindberg and Houe, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). These programmes have demonstrated that early epidemiological characterization is critical for designing proportionate and cost-effective BVD control strategies. In contrast, epidemiological data from many rapidly developing dairy sectors, including those in the Middle East, and the United Arab Emirates (UAE) in particular, remain limited.\u003c/p\u003e \u003cp\u003eThe UAE has a relatively young but rapidly expanding commercial dairy industry, developed as part of a national food security strategy. Currently, there are 21 commercial dairy farms across the UAE, housing approximately 67,000 cattle (Personal communication, ADAFSA, 2025). Sixteen of these farms are located within the Emirate of Abu Dhabi (EAD), with the largest concentration in the Al Ain region. Dairy production systems in the country are characterized by intensive management, high stocking densities and reliance on imported feed resources. Importantly, foundation breeding stock was historically sourced from countries where BVDV is endemic, including several European nations, North America, Australia and South Africa. International movement of cattle is a recognised risk factor for introduction and dissemination of BVDV (Lindberg and Houe, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2005\u003c/span\u003e), suggesting that the UAE dairy sector may be vulnerable to viral establishment.\u003c/p\u003e \u003cp\u003eMost commercial dairy farms in EAD routinely vaccinate their cattle against BVDV. However, the true epidemiological status of the virus within the regional cattle population remains uncertain. Anecdotal observations from field veterinarians have suggested possible ongoing viral circulation, yet such impressions have not been substantiated by systematically generated prevalence data. In the absence of structured surveillance and published epidemiological evidence, it is not possible to determine whether BVDV actually exists in the country and if it does whether the infections are increasing, stable or declining within the commercial dairy sector. Furthermore, vaccines currently administered in the region are not selected based on documented circulation of specific BVDV genotypes or biotypes within the UAE cattle population. This is despite the fact that BVDV exhibits considerable genetic and antigenic diversity (Liu et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Yeşilbağ et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), and mismatches between vaccine and field virus strains may compromise vaccine-induced protective immunity. Without baseline epidemiological and virological characterization, the strategic rationale underpinning vaccination programmes cannot be critically evaluated. Notably, in low-prevalence or early-endemic settings, vaccination alone without concurrent identification and removal of PI animals may be insufficient to interrupt transmission (Lindberg and Houe, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Taken together, the above factors highlight a critical knowledge gap in the epidemiology of BVDV within the UAE dairy cattle sector. Structured, evidence-based surveillance is required to establish the current burden and distribution of infection and to inform proportionate preventive strategies.\u003c/p\u003e \u003cp\u003eAgainst the above background, the aim of this study was to determine baseline animal- and herd-level BVDV antigen prevalence in commercial dairy cattle in the EAD and to contextualize the findings within the regional epidemiological literature. The study results are intended to inform development of an integrated, risk-based BVD control strategy aligning vaccination, biosecurity, and targeted PI detection with the local epidemiological context. The baseline data will also guide future molecular epidemiological investigations needed to support vaccine\u0026ndash;field BVDV strain matching.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Study design and sampling strategy\u003c/h2\u003e \u003cp\u003eA cross-sectional study design was employed to investigate BVDV prevalence, with the sampling frame comprising all registered commercial dairy farms in the Emirate of Abu Dhabi (EAD), UAE at the time of study implementation. Nine farms consented to participate, representing the majority of large-scale commercial dairy operations in the region. Within each farm, animals were selected using systematic random sampling from available herd lists. Sampling was designed to proportionally represent major production groups, including lactating cows, dry cows, and replacement heifers. The sample size required to estimate prevalence under simple random sampling was calculated using the standard formula:\u003c/p\u003e\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e \u003c/p\u003e \u003cp\u003ewhere Z\u0026thinsp;=\u0026thinsp;1.96Z\u0026thinsp;=\u0026thinsp;1.96Z\u0026thinsp;=\u0026thinsp;1.96 (95% confidence level), P\u0026thinsp;=\u0026thinsp;0.01P\u0026thinsp;=\u0026thinsp;0.01P\u0026thinsp;=\u0026thinsp;0.01 (expected prevalence), and d\u0026thinsp;=\u0026thinsp;0.005d\u0026thinsp;=\u0026thinsp;0.005d\u0026thinsp;=\u0026thinsp;0.005 (absolute precision). This yielded a theoretical minimum sample size of approximately 1,521 animals. However, due to logistical and operational constraints, a total of 681 animals were sampled. Although lower than the theoretical requirement, the achieved sample size was sufficient to detect low-prevalence infection and provide baseline estimates of BVDV antigen in the study cattle population. Furthermore, given that cattle were clustered within farms, potential intra-herd correlation was accounted for. The design effect (DEFF) was estimated using:\u003c/p\u003e \u003cp\u003eDEFF\u0026thinsp;=\u0026thinsp;1+(m\u0026thinsp;\u0026minus;\u0026thinsp;1)\u0026times;ICC\u003c/p\u003e \u003cp\u003ewhere \u0026ldquo;m\u0026rdquo; represents the average cluster size and \u0026ldquo;ICC\u0026rdquo; the intra-cluster correlation coefficient. Assuming an average cluster size of approximately 66 animals and an ICC of 0.05, consistent with published estimates for infectious disease clustering, the design effect was approximately 4.25. This corresponded to an effective sample size of approximately 203 animals after adjustment for clustering.\u003c/p\u003e \u003cp\u003e \u003cb\u003e2.2. Ethical Approval and Sample Collection\u003c/b\u003e \u003c/p\u003e \u003cp\u003eBefore blood collections, this research was approved by the United Arab Emirates Animal Research Ethics Committee (Application No: ERA_2025_7604, titled: Molecular Epidemiology and Prevalence of Bovine Viral Diarrhoea Virus in Dairy Cattle Herds in The Al Ain Region) with Certificate # ERA_2025_7604 issued on the 28th August, 2025. Vacutainer tubes with a clotting activator were used to collect jugular blood from study cattle and thereafter the samples transported to the laboratory in a cool box. At the laboratory, the blood samples were allowed to clot overnight at 4\u0026deg;C in the refrigerator and the serum separated by centrifugation the following day. Serum samples were stored at -80\u0026deg;C until testing.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.3 BVDV Antigen Capture ELISA\u003c/h2\u003e \u003cp\u003eIndividual serum samples were tested for BVDV antigen using a commercial antigen-capture ELISA (IDEXX BVDV Ag/Serum Plus Test, IDEXX Laboratories Inc., Westbrook, ME, USA), in accordance with the manufacturer\u0026rsquo;s instructions. The assay is intended for use with bovine serum and other individual sample types and was performed on serum collected from each animal. Briefly, serum specimens together with assay controls were dispensed into antibody-coated microplate wells to permit capture of BVDV antigen. Following incubation and washing to remove unbound material, an enzyme-conjugated detection secondary antibody was applied, and color development was achieved using the supplied chromogenic substrate. The reaction was terminated with stop solution, and the plates were read at 450 nm using spectrophotometer (Multiskan Sky Thermo Scientific, Singapore). The OD\u003csub\u003e450\u003c/sub\u003e reading for the samples were interpreted based on the sample-to-positive (S/P) ratio or threshold criteria provided in the kit protocol. Samples exceeding the manufacturer-defined cut-off value were considered positive for BVDV antigen. Quality control was ensured through inclusion of kit-provided positive and negative controls in each assay run, and test validity was confirmed according to manufacturer acceptance criteria (IDEXX Laboratories Inc., Westbrook, ME, USA).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Regional Epidemiological Literature Review and Contextual Analysis\u003c/h2\u003e \u003cp\u003eTo contextualize the prevalence estimates generated in this study, a structured narrative review of published literature on BVDV epidemiology in the Middle East and neighboring regions was undertaken. Peer-reviewed articles were identified through electronic database searches (e.g., PubMed, Scopus and Web of Science) using combinations of keywords including \u0026ldquo;BVDV,\u0026rdquo; \u0026ldquo;bovine viral diarrhoea,\u0026rdquo; \u0026ldquo;prevalence,\u0026rdquo; \u0026ldquo;seroprevalence,\u0026rdquo; \u0026ldquo;antigen,\u0026rdquo; \u0026ldquo;PI,\u0026rdquo; and country names within West Asia and North Africa. Studies reporting animal-level or herd-level prevalence in dairy cattle populations were prioritized yielding eight papers that met the inclusion criteria. Both antigen detection and serological investigations were considered to allow interpretation of active infection and cumulative exposure patterns. Extracted information included country, study population, diagnostic method, sample size and reported prevalence (Table\u0026nbsp;2). Findings from these regional studies were used descriptively to frame and interpret the UAE prevalence data within a broader epidemiological context.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.5 Statistical data analysis\u003c/h2\u003e \u003cp\u003eAnimal-level apparent prevalence was calculated as the proportion of antigen-positive animals among the total number tested. Exact binomial (Clopper\u0026ndash;Pearson) 95% confidence intervals were computed to account for the low number of positive outcomes. Herd-level prevalence was defined as the proportion of farms with at least one antigen-positive animal, and farm-level prevalence estimates were calculated with corresponding exact confidence intervals. Given the small number of positive observations, multivariable modelling was not performed. Statistical comparisons between selected farms were conducted using Fisher\u0026rsquo;s exact test. All statistical analyses were performed using standard epidemiological methods consistent with preventive veterinary research practice. Prevalence estimates were calculated as unweighted proportions. Confidence intervals were not adjusted for clustering and may therefore underestimate uncertainty; results should be interpreted accordingly.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 681 cattle were tested, of which 7 were positive for BVDV antigen, yielding an overall apparent prevalence of 1.02% (95% CI: 0.27\u0026ndash;1.79%) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In addition, BVDV antigen-positive animals were detected in 3 of 9 farms giving a herd prevalence of 33.3% and farm-level prevalence of BVDV antigen ranged from 0% to 9.1%, with the highest prevalence observed in Farm 13 (3/33). However, most farms (6/9) had no detectable antigen-positive animals. Furthermore, lower within-herd prevalence estimates were observed in larger herds (e.g., Farms 7 and 11), whereas higher apparent prevalence and greater variability were observed in smaller sampled groups, reflecting the influence of sample size on precision. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes the number of cattle tested per farm using BVDV antigen-capture ELISA, together with the number of antigen-positive and antigen-negative animals and the corresponding apparent prevalence.\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\u003eFarm-level results of BVDV antigen detection in commercial dairy herds in the Emirate of Abu Dhabi.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal cattle population at study farm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePlanned sample size\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eActual number of samples tested by antigen Capture ELISA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePositive for BVDV antigen\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNegative for BVDV antigen\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBVDV Antigen Prevalence (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e861\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e182\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\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1050\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e292\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3372\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e298\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e832\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e280\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\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1641\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e248\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFarm 13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTOTALS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9,636\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e281\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e674\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.02\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 \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eabove summarizes farm-level detection of bovine viral diarrhoea virus (BVDV) antigen in commercial dairy cattle herds in the Emirate of Abu Dhabi, United Arab Emirates. The table presents the total herd size, number of animals tested by antigen-capture ELISA, number of antigen-positive and antigen-negative animals, and the corresponding apparent prevalence for each farm.\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=\"left\" 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=\"left\" 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 \u003cp\u003eCountry / region\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePopulation \u0026amp; diagnostic method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAnimal-level prevalence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHerd-level prevalence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKey reference(s)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUAE (Emirate of Abu Dhabi)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCommercial dairy cattle, Ag-ELISA (current study)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.02% antigen prevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33.3% antigen prevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMeta-analytic summary of the present UAE study data\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJordan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62 non-vaccinated dairy herds (671 cows), indirect ELISA (antibody detection)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.6% true seroprevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e80.7% true herd seroprevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTalafha et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2009\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIran\u003c/p\u003e \u003cp\u003e(national)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMultiple studies, various dairy systems, antibody ELISA \u0026amp; virus neutralization test\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52% pooled seroprevalence (95% CI 40.1\u0026ndash;63.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eJokar et al. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIran\u003c/p\u003e \u003cp\u003e(central desert)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e800 cows in 76 dairy herds, indirect ELISA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.8% seroprevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e91.6% herd-level seropositivity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKarimi et al. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTurkey (Aegean Region)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e552 cows in 48 unvaccinated dairy herds, indirect ELISA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48.4% seropositivity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e89.6% herd-level prevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eİnce \u0026amp; Ayaz (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEgypt\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDairy herds, Indirect ELISA (compiled)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.0% seroprevalence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSelim et al. (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2018\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIraq\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDairy cattle, Ag-ELISA (compiled), RT-PCR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.46% antigen prevalence; 13.96% by RT-PCR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHasan and AlSaad, (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2018\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIraq\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAg-ELISA; Indirect ELISA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.1% antigen; 23.57% antibody\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eJarulla et al. (2012)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSaudi Arabia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCattle, Ag-ELISA, indirect ELISA, RT-PCR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.0% seroprevalence (RNA detected in 12.0% of the cattle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAl-Mubarak et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e)\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\u003eTable\u0026nbsp;2.\u003c/b\u003e Reported BVDV prevalence in dairy cattle in selected Middle Eastern countries and comparison with findings from the Emirate of Abu Dhabi, UAE. Seroprevalence estimates reflect cumulative exposure and are not directly comparable to antigen-based estimates of active infection.\u003c/p\u003e \u003cp\u003ePresented in Table\u0026nbsp;2 is a summary of published animal- and herd-level BVDV prevalence estimates from selected Middle Eastern countries, including serological (antibody-based) and antigen and BVDV nucleic acid detection studies, alongside the present BVDV survey in the EAD. Differences in diagnostic methods (Ag-ELISA vs. antibody ELISA or virus neutralization), study populations, management systems and vaccination status should be considered when interpreting cross-country comparisons. The table contextualizes the relatively low antigen prevalence observed in the EAD within the broader regional epidemiological landscape. In respect to Table\u0026nbsp;2, it should be noted that seroprevalence estimates derived from the regional literature reflect cumulative exposure and are not directly comparable to antigen-based estimates of active infection.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTo our knowledge, this study provides the first systematically derived estimates of BVDV antigen prevalence in commercial dairy cattle in the EAD in the UAE. At the individual-animal level, antigen prevalence was 1.02%, which is relatively low, yet BVDV-positive cattle were detected in 3 out of 9 (33.3%) herds, indicating that the virus is present but not widely disseminated. This profile, of low animal-level prevalence combined with scattered herd-level infection, is consistent with an early-endemic or controlled scenario in which PI animals occur sporadically and onward transmission is limited (Houe et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Moennig and Becher, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). When interpreted against regional data, the present EAD findings sit at the lower end of the spectrum for West Asia and North Africa. A global meta-analysis reported higher PI prevalence in West Asia of \u0026gt;\u0026thinsp;1.6% than in Europe and Australia (\u0026le;\u0026thinsp;0.8%), reflecting weaker or absent control programmes in many countries (Scharnb\u0026ouml;ck et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Al-Mubarak et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In the Middle East, reported PI prevalence is approximately 1.5% in Egypt and 0.8% in Iraq, with antigen detection by Ag-ELISA around 6.0% in both countries (Al-Mubarak et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), compared to 1.02% detected in dairy cattle from the EAD, UAE in this study. The low BVDV antigen prevalence observed in this study is, therefore, broadly compatible with the antigen (PI animals) prevalence cited for Egypt and Iraq (Al-Mubarak et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In contrast, however, serological surveys from geographically nearby countries to the UAE indicate substantial historical exposure to BVDV. A systematic review and meta-analysis from Iran estimated a pooled seroprevalence of 52.0% (95% CI 40.1\u0026ndash;63.9) across cattle populations (Jokar et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), with more recent work in the central desert of Iran reporting animal-level seroprevalence of 66.8% and herd-level seropositivity of 91.6% in intensively managed Holstein-Friesian herds (Karimi et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). In Jordan, Talafha et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) reported true seroprevalence estimates of 31.6% at animal level and 80.7% at herd level in non-vaccinated dairy herds, again suggesting long-standing endemic circulation under semi-intensive management. In Iraq, BVDV antigen prevalence has been reported at 7.1% (Jarullah et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) and 5.4% (Hasan and AlSaad, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). In the Aegean Region of Turkey, on the other hand, animal-level seropositivity of 48.4% and herd-level prevalence of 89.6% were recently documented in unvaccinated dairy herds (Ince and Ayaz, 2023). Together, these data emphasize that the EAD dairy sector may currently be experiencing a relatively favourable epidemiological situation compared with other regional dairy industries, despite broadly similar climatic constraints and heavy reliance on imported genetics. The divergence between the low antigen prevalence reported here and the moderate-to-high seroprevalence documented in neighbouring Middle Eastern countries also highlights the importance of distinguishing active infection from cumulative exposure. Serology captures both past and present infection, whereas antigen detection and virus isolation primarily reflect current viraemia and the presence of PI animals (Houe, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1995\u003c/span\u003e; Jokar et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In contexts where effective control measures or partial immunity have been established, it is epidemiologically plausible to observe high antibody prevalence with low concurrent antigen detection (Moennig and Becher, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Conversely, in completely na\u0026iuml;ve herds, low seroprevalence and low antigen prevalence might both be expected. Without paired antibody data, the present study cannot fully resolve which of these scenarios best describes the EAD herds; however, continuous vaccination reported by most farms and the historical importation of cattle from BVD-endemic regions suggest that some degree of previous exposure is likely. From a quantitative epidemiology standpoint, the cluster-sampled design and explicit accounting for intra-herd correlation strengthen the inference compared with na\u0026iuml;ve binomial approaches. Adjustment for clustering reduces the effective sample size and widens confidence intervals, acknowledging that animals within the same herd share exposures and infection status is not independent (McDermott and Schukken, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; Dohoo et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). In this study, the design effect implied that point estimates of BVDV antigen prevalence, although low, were somewhat imprecise; thus, while widespread infection can be confidently ruled out, small, localized clusters of higher prevalence cannot be excluded. Furthermore, as confidence intervals were not adjusted for clustering, the reported uncertainty may be underestimated and should be interpreted with caution. This uncertainty underlines the importance of repeated cross-sectional surveys or longitudinal monitoring to detect temporal trends, particularly in a rapidly evolving production system. The low number of antigen-positive animals must also be interpreted in light of diagnostic performance. Ag-ELISA is widely used for BVDV antigen detection, with good sensitivity and specificity in serum and tissue samples (Hanon et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Hanon et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). However, in very low-prevalence settings, even small imperfections in test performance can materially affect predictive values and apparent prevalence (Scharnb\u0026ouml;ck et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Where vaccination is intensive, transient viraemia in recently vaccinated animals, interference from maternal antibodies in young calves, or sample handling constraints may further complicate interpretation (Hanon et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Moennig and Becher, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). These considerations argue for confirmatory testing of BVDV antigen positive cattle using RT-PCR as well as re-sampling those animals for PI classification. Ideally, complementary serology and bulk-tank milk surveillance would be required to characterize true BVDV infection status at herd level (Hanon et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Guelbenzu-Gonzalo et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The management context in the EAD, UAE is also highly relevant to understanding observed patterns. Farms in this survey represented large, intensively managed enterprises, with high stocking densities and near-complete dependence on imported feed which in principle are conditions that favour transmission of respiratory and enteric pathogens (Karimi et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). At the same time, these operations tend to have strong veterinary oversight, controlled biosecurity and structured vaccination programmes, in contrast to many smallholder or mixed systems in the region (Talafha et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Jokar et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Intensification under tight biosecurity may therefore simultaneously elevate the risk of explosive outbreaks if PI animals are introduced and reduce the probability of sustained endemic circulation if surveillance and removal are effectively implemented (Van Roon et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEconomically, even low prevalences of PI animals can be highly consequential. BVDV is associated with substantial losses through decreased fertility, early embryonic death, abortions, immunosuppression and increased calf morbidity and mortality (Chase, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Elsewhere, controlled challenge studies and observational data have shown that PI animals act as strong infection amplifiers within herds, and their presence is consistently identified as a key driver of reproductive and production losses (Grooms, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Loneragan and Thomson, 2005; Van Roon et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In low-prevalence contexts such as the EAD, targeted identification and removal of PI animals, supported by high-quality biosecurity and risk-based surveillance, is generally more cost-effective than blanket vaccination alone (Lindberg and Houe, 2006; Moennig and Becher, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSeveral limitations should be considered when interpreting the present study findings. The cross-sectional design provides a temporal snapshot but cannot distinguish transiently infected from PI animals without follow-up testing (Houe, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1995\u003c/span\u003e; Al-Mubarak et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Although the sampling strategy accounted for clustering, logistical constraints limited the number of animals sampled per herd, particularly in some smaller farms, which may have reduced the ability to detect within-herd heterogeneity. Besides, sampling was also restricted to commercial dairy units in the EAD and therefore these data cannot be generalized to the BVDV dynamics in other emirates, beef enterprises or smallholder cattle production systems. The exclusive reliance on BVDV antigen detection precludes inference on past exposure and herd immunity, as no antibody testing was undertaken. Finally, molecular characterization of detected viruses was beyond the scope of this survey; consequently, the circulating genotypes and their relationship to vaccine strains remain unknown, despite evidence from Iran, Turkey and other regions that indicate substantial genetic diversity and genotype-specific patterns of spread exist in the Middle East (Liu et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Yesilbag et al., 2008; Khezri, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). These limitations underscore the need for longitudinal monitoring, combined antigen\u0026ndash;antibody testing, and molecular epidemiological studies to fully characterize BVDV dynamics in the UAE.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, this study demonstrates a very low animal-level prevalence of BVDV antigen in commercial dairy cattle in the Emirate of Abu Dhabi, with infection confined to a minority of herds. In the context of the high seroprevalence reported from other Middle Eastern dairy systems and the elevated PI prevalences described in regional meta-analyses, these findings suggest that the UAE dairy sector remains at a relatively favourable stage in the BVDV epidemiological trajectory, where elimination via targeted measures remains feasible. The combination of structured, cluster-aware sampling and farm-level detection of infection provides an important baseline for future surveillance and control efforts. The data obtained in this study support a risk-based control strategy that prioritizes systematic PI detection and removal, rigorous biosecurity, particularly relating to animal movements and replacement stock, and enhanced import screening, with vaccination used strategically and ideally informed by molecular data pertaining to circulating BVDV genotypes. Expanding surveillance to include serology, repeated cross-sectional surveys and broader geographic coverage will be critical to detect temporal changes in BVDV prevalence, refine economic evaluations of alternative control scenarios and guide evidence-based policy decisions for BVD control and potential eradication in the UAE.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research project was financially supported under UPAR Grant No G00004519 by the United Arab Emirates University under a research funding mechanism that promotes mentoring undergraduate students in research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo potential conflicts of interest are reported by the author(s).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research project was approved by the Animal Research Ethics Committee of the United Arab Emirates University (Application No: ERA_2025_7604, titled: Molecular Epidemiology and Prevalence of Bovine Viral Diarrhoea Virus in Dairy Cattle Herds in The Al Ain Region; Certificate # ERA_2025_7604 issued on the 28th August, 2025).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRobert Barigye was project Principal Investigator who, along with co-authors Asha Antony, and Gobena Ameni conceptualized and wrote the research proposal, contributed to data analysis and drafting of the manuscript. Nabeeha A. Hassan and Aboma Zewude are research assistants who did the laboratory testing of the blood samples. Last but not least, co-author Shamma A.R. Al-Ghaithi is an undergraduate veterinary student who was mentored and participated in the laboratory testing of samples as a requirement of the UPAR Grant. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll veterinarians and staff at the study dairy farms in the Emirate of Abu Dhabi are acknowledged for helping with the collection of blood samples. The management of those farms is also recognized for permitting the condition of these studies.\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAl-Mubarak, A.I.A., Al-Kubati, A.A.G., Skeikh, A., Hussen, J., Kandeel, M., Flemban, B. and Hemida, M.G., 2023. 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Variability and global distribution of subgenotypes of bovine viral diarrhea virus. \u003cem\u003eViruses\u003c/em\u003e, 9(6), p.128.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"tropical-animal-health-and-production","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trop","sideBox":"Learn more about [Tropical Animal Health and Production](https://www.springer.com/journal/11250)","snPcode":"11250","submissionUrl":"https://submission.nature.com/new-submission/11250/3","title":"Tropical Animal Health and Production","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"BVDV, antigen prevalence, dairy cattle, Emirate of Abu Dhabi, MENA Region, United Arab Emirates","lastPublishedDoi":"10.21203/rs.3.rs-9242329/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9242329/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBovine viral diarrhoea virus (BVDV) is a globally significant pathogen of cattle, causing substantial economic losses through reproductive failure, immunosuppression, and reduced productivity. This cross-sectional study estimated animal- and herd-level prevalence of BVDV antigen in commercial dairy herds in the Emirate of Abu Dhabi (EAD), UAE, and contextualized the findings within the epidemiological landscape of the Middle East and North Africa (MENA) region. A total of 681 cattle from nine large-scale dairy farms were sampled using a stratified systematic approach and tested for BVDV antigen using a commercial antigen-capture ELISA. Apparent animal-level prevalence was 1.02% (7/681; 95% CI: 0.27\u0026ndash;1.79%), while herd-level prevalence was 33.3% (3/9 farms). Within-herd prevalence ranged from 0% to 9.1%, with most farms (6/9) showing no antigen-positive animals. Comparative analysis with published regional data indicates that BVDV antigen prevalence in EAD dairy herds is substantially lower than estimates reported in several MENA countries, where both antigen detection and seroprevalence studies suggest more widespread viral circulation. The observed epidemiological pattern, characterized by low animal-level prevalence but presence across multiple herds, is consistent with limited viral circulation, potentially reflecting an early-endemic or partially controlled state. However, as antigen detection identifies current infection but does not distinguish transient from persistent infection, follow-up testing is required to confirm persistently infected animals. These findings provide the first baseline evidence of BVDV infection in UAE dairy cattle and support the implementation of risk-based control strategies, including targeted detection and removal of persistently infected animals, strengthened biosecurity, and strategic vaccination informed by regional epidemiology.\u003c/p\u003e","manuscriptTitle":"Low BVDV Antigen Prevalence in Dairy Cattle in the Emirate of Abu Dhabi, UAE: A Cross-Sectional Study with Regional Comparison","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-08 11:44:42","doi":"10.21203/rs.3.rs-9242329/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-04-29T16:43:54+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-29T12:23:15+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-02T06:29:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"Tropical Animal Health and Production","date":"2026-03-30T06:24:37+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"tropical-animal-health-and-production","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trop","sideBox":"Learn more about [Tropical Animal Health and Production](https://www.springer.com/journal/11250)","snPcode":"11250","submissionUrl":"https://submission.nature.com/new-submission/11250/3","title":"Tropical Animal Health and Production","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"3e66a125-a93f-4a50-b1f4-a9aba02e9b39","owner":[],"postedDate":"May 8th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T11:44:42+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-08 11:44:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9242329","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9242329","identity":"rs-9242329","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}