title: Persistence of West Nile virus immunoglobulin M antibodies, Greece.
abstract: A major outbreak of West Nile virus (WNV) lineage 2 infections was observed in 2010 in Greece. In order to check the persistence of WNV IgM antibodies, a second serum sample taken 75-180 days after onset of the illness from 29 patients with WNV infection was tested. A third sample was obtained 181-270 days after onset of the illness from 8 of the 12 patients with IgM-positive second sample. Mixed effects linear regression analysis indicated that the approximate time at which IgM index became negative was 164 (95% confidence interval, 95% CI 99-236) days after the symptoms' onset. Persistence of IgM antibodies was observed in 12% of patients at 181-270 days of follow-up. A sharp decrease in the IgM levels was observed, mainly in patients who had high IgM index value in the acute phase. All patients were WNV IgG positive at the follow-up.
authors.affiliation: Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. annap@med.auth.gr
authors.forename: Anna
authors.initials: A
authors.lastname: Papa
authors.forename: Kostas
authors.initials: K
authors.lastname: Danis
authors.forename: Afroditi
authors.initials: A
authors.lastname: Athanasiadou
authors.forename: Maria
authors.initials: M
authors.lastname: Delianidou
authors.forename: Takis
authors.initials: T
authors.lastname: Panagiotopoulos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006115:Greece; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014901:West Nile Fever / Q000097:blood / Q000276:immunology* / Q000821:virology; D014902:West Nile virus / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M