title: Serological evidence of West Nile virus infection in wild migratory and resident water birds in Eastern and Northern India.
abstract: To assess West Nile virus (WNV) infection in wild resident and migratory birds, we tested 3887 samples from 1784 birds belonging to 119 identified species within 30 families collected during 2008-10 from 13 states in India. The serum samples were tested for WNV antibodies initially by a competition ELISA and subsequently by a micro-plaque reduction neutralization test (Micro-PRNT), whereas tracheal and cloacal swabs were subjected to real-time RT-PCR for the detection of the WNV RNA. Twenty six birds (2.46%) out of 1058 tested showed evidence of flavivirus antibodies by ELISA. End point neutralization antibody determinations for WNV and Japanese encephalitis virus (JEV) showed that of the 22 ELISA positive sera, WNV-specific neutralizing antibodies were detected in 17 samples representing nine species of wild birds (residents: Purple swamphen, Little cormorant, Little egret, Black ibis and Spot-billed duck; residents with winter influx: Common coot and Mallard; migratory birds: Ruff and Purple heron), and two samples were positive for both WNV and JEV antibodies. The WNV-specific antibodies were most commonly detected in Mallards and Common coots. WNV genomic RNA was not detected by real-time RT-PCR. The results in this study suggest that wild resident birds are infected occasionally and wild migratory birds rarely with WNV. Additionally, our study provides evidence of WNV infection in eastern and northern India for the first time.
authors.affiliation: High Security Animal Disease Laboratory, Indian Veterinary Research Institute, Anand Nagar, Bhopal, Madhya Pradesh 462 021, India. mishranir@rediffmail.com
authors.forename: Niranjan
authors.initials: N
authors.lastname: Mishra
authors.forename: S
authors.initials: S
authors.lastname: Kalaiyarasu
authors.forename: S
authors.initials: S
authors.lastname: Nagarajan
authors.forename: Mandava Venkata Subba
authors.initials: MV
authors.lastname: Rao
authors.forename: Acty
authors.initials: A
authors.lastname: George
authors.forename: R
authors.initials: R
authors.lastname: Sridevi
authors.forename: Sthita Pragnya
authors.initials: SP
authors.lastname: Behera
authors.forename: Shiv Chandra
authors.initials: SC
authors.lastname: Dubey
authors.forename: Tracy
authors.initials: T
authors.lastname: McCracken
authors.forename: Scott H
authors.initials: SH
authors.lastname: Newman
mesh_terms: D000818:Animals; D000835:Animals, Wild; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D001715:Bird Diseases / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D001717:Birds; D004664:Encephalitis Virus, Japanese / Q000235:genetics / Q000302:isolation & purification; D004672:Encephalitis, Japanese / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D015994:Incidence; D007194:India / Q000453:epidemiology; D060106:Lakes; D009500:Neutralization Tests; D045483:Rivers; D014901:West Nile Fever / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000235:genetics / Q000302:isolation & purification; D053833:Wetlands
chemical_list: D000914:Antibodies, Viral