Serologic diagnosis of West Nile and St. Louis encephalitis virus infections in domestic chickens.
Adult domestic chickens were infected with West Nile virus (WNV) or St. Louis encephalitis virus (SLEV) and challenged with homologous or heterologous virus at 21 or 56 days postinfection (dpi). Sera were collected at selected time points after infection and assayed by enzyme immunoassay (EIA), plaque reduction neutralization test (PRNT), and a Western blot (WB) alternative to PRNT. EIA results were sensitive and accurate (few false positives) but not specific, requiring a confirmatory test to determine virus infection history. PRNT results generally were specific until challenge, after which test results were frequently equivocal and inadequate to determine first or second infecting virus. WB results confirmed the serologic cross-reactivity between WNV and SLEV envelope protein. Non-structural protein 1 and pre-membrane protein reactivities were highly specific for WNV during SLEV infection, but less specific for SLEV during WNV infection. WB and PRNT specificities were similar for both viruses from 6 to 14 dpi, and sensitivities to WNV were virtually identical.
Patiris
Peter J
PJ
California Department of Public Health, Viral and Rickettsial Disease Laboratory, Richmond, California 94804, USA. ppatiris@dhs.ca.gov
Oceguera
Leopoldo F
LF
Peck
George W
GW
Chiles
Robert E
RE
Reisen
William K
WK
Hanson
Carl V
CV
D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D002645:Chickens; D004665:Encephalitis Virus, St. Louis / Q000302:isolation & purification; D004674:Encephalitis, St. Louis / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D009500:Neutralization Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000097:blood* / Q000175:diagnosis / Q000821:virology; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000662:veterinary; D013997:Time Factors; D014766:Viremia; D014901:West Nile Fever / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D014902:West Nile virus / Q000302:isolation & purification