Cross-sectional serosurvey and associated factors of bluetongue virus antibodies presence in small ruminants of Nepal

BMC Research Notes

Richard A Bowen⁶  Bishwas Sharma¹  Nanda Prakash Joshi⁴  Doj Raj Khanal⁵  Ishwari Prasad Dhakal¹  Surendra Karki²  Tara Nath Gaire³ 

[1] Institute of Agriculture and Animal Science, Tribhuvan University, Chitwan, Nepal;Department of Pathobiology, University of Illinois, Urbana-Champaign, IL, USA;Directorate of Animal Health, Tripureshwor, Kathmandu, Nepal;Department of Large Animal Clinical Science, Michigan State University, East Lansing, MI, USA;Animal Health Research Division, Nepal Agricultural Research Council, Lalitpur, Nepal;Department of Biomedical Science, Colorado State University, Fort Collins, CO, USA

关键词: Nepal;    Associated factors;    c-ELISA;    Seroprevalence;    Bluetongue virus;   

Others  :  1127374
DOI  :  10.1186/1756-0500-7-691

 received in 2014-06-19, accepted in 2014-10-02,  发布年份 2014

【 摘 要 】

Background

Bluetongue (BT) is an infectious, insect-borne viral disease primarily affecting sheep and occasionally cattle and goats. In Nepal, BT is an emerging disease of economic importance. The objective of this study was to estimate the seroprevalence of BT virus (BTV) in small ruminants of two eco-zones of Nepal, Hills and Terai, and to identify the factors associated with virus exposure. We conducted a cross-sectional serosurvey from March 2012 through February 2013 by sampling 318 small ruminants (184 sheep and 134 goats) from seven clusters (villages) of selected vulnerable communities of Chitwan (Terai) and Lamjung (Hills) Districts of Nepal.

Results

Of the 318 serum sample tested, 27.9% [95% confidence interval (CI): 23.1- 33.2] were positive for BTV antibodies (25.0% sheep and 31.3% goats). Bivariate analysis indicated a positive association between seroconversion to BTV and flock size, eco-zone, breed, and contact history with cattle. Additionally, in female sheep and goats, a history of abortion was positively associated with seropositivity to BTV. However, the final multivariable model, after controlling for clustering of animals within the villages, identified only history of abortion and breed as the factors significantly associated with BT seropositivity in female sheep and goats. Based on this model, female small ruminants having a history of abortion were more likely to be seropositive compared to those without such history [Odds Ratio (OR) = 46.14 (95% CI: 11.66- 182.5)]. Exotic breeds were more likely to be seropositive compared to indigenous breeds [OR = 9.04 (95% CI: 3.08- 24.46)] while the risk for BTV seropositivity was not significantly different between indigenous and cross breeds.

Conclusions

Our results showed that nearly a quarter of small ruminants in two regions of Nepal were seropositive for BTV, indicating wide exposure of small ruminants to this pathogen. We identified history of abortion and breed as factors significantly associated with the seropositivity of BTV. We recommend that surveillance for BTV infection in Nepal be strengthened and that it would be valuable to enhance the education of farmers about the possible impacts of this disease.

【 授权许可】

   
2014 Gaire et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

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