[Specific antibodies in convalescents after West Nile fever]

Blood serum samples were obtained from patients with West Nile fever (WNF) from the city of Volgograd and its region within the disease weeks 1-3 (July-October 1999), month 6-7 (May_June 2000) and month 12-18 (May-June 2001) after the disease onset. In the sera of 40 patients examined 6-7 months after the disease onset IgM-antibodies to WNF virus were absent (dilution 1:50), IgG ones were detected in 35 patients (87.5%). 18 months after the disease IgG-antibodies were identified in 23 of 26 convalescents (88.5%). The serum samples obtained in autumn 1999 and May-June 2000 contained antihemagglutinins to WNF virus for 6-7 months in all 18 patients. In May-June 2000 the sera were positive in 38 convalescents who had WNF in 1999.