Serological Evidence of West Nile Virus in Wild Birds in Bangladesh.

Ariful Islam,Mohammad Mahmudul Hassan,Jinnat Ferdous,Mohammad Ziaur Rahman,Josefina Abedin,Md Ahasanul Hoque,Mohammad Enayet Hossain,Shariful Islam,Md Kaisar Rahman

doi:10.3390/vetsci7040164

Abstract

West Nile Virus (WNV) is a vector-borne zoonotic disease maintained in a sylvatic cycle involving mosquito vectors and birds. To detect WNV and other flavivirus infections in wild resident and migratory birds, we tested 184 samples from 19 identified species within nine families collected during 2012–2016 from four districts in Bangladesh. We tested serum samples for the immunoglobulin G (IgG) antibody against WNV using competitive Enzyme-Linked Immunosorbent Assay (c-ELISA), whereas tracheal and cloacal swabs were subjected to consensus Polymerase Chain Reaction (c-PCR) for the detection of the flavivirus RNA. Overall, we detected 11.9% (n = 22; 95% CI: 0.07–0.16) samples were seropositive, including 15.9% in the migratory wild birds and 10.7% in the resident wild birds. The migratory wild Tufted duck showed 28.5% seropositivity, whereas the resident wild house crows showed 12.5% seropositivity. None of the swab samples was positive for flavivirus RNA infection (0%, n = 184; 95% CI: 0–0.019). These study findings recommend continued surveillance for early detection and to better understand the epidemiology of WNV and other flavivirus circulation in both birds and mosquitoes in Bangladesh.

Highlights

West Nile Virus (WNV) is an emerging zoonotic arbovirus, having enveloped positive-sense single-stranded RNA belonging to the family Flaviviridae in the genus Flavivirus [1]
The overall sero- and viral prevalence of WNV in wild birds of Bangladesh was 11.9% (n = 184; 95% confidence interval (CI): 0.07–0.16) and 0% (n = 184, 95%CI: 0–0.019), respectively
Wetlands are a suitable place where domestic birds and resident wild birds meet with migratory birds in winter

Summary

Introduction

West Nile Virus (WNV) is an emerging zoonotic arbovirus, having enveloped positive-sense single-stranded RNA belonging to the family Flaviviridae in the genus Flavivirus [1]. The detection of WNV in New York in the US in 1999 showed the first introduction of an Old World flavivirus into the New World [3], and within three years the virus had spread throughout the US, moving through Canada, Mexico, Central America, and the Caribbean, and down to Argentina by 2006 [4]. WNV is considered an endemic disease in the US. In the 77 years since its detection, the virus has spread worldwide on all continents except for Antarctica and caused epidemic outbreaks, and is considered the most critical causative agent.

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Conclusion