title: Prevalence of IgM and IgG antibodies to West Nile virus among blood donors in an affected area of north-eastern Italy, summer 2009.
abstract: Following reports of West Nile neuroinvasive disease in the north-eastern area of Italy in 2009, all blood donations dating from the period between 1 August and 31 October 2009 in the Rovigo province of the Veneto region were routinely checked to exclude those with a positive nucleic acid test for West Nile virus (WNV). Only one of 5,726 blood donations was positive (17.5 per 100,000 donations; 95% confidence interval (CI): 0.4–97.3). In addition, a selection of 2,507 blood donations collected during the period from 20 July to 15 November 2009 were screened by ELISA for IgG and IgM antibodies against WNV. A positive result was received for 94 of them. The positive sera were further evaluated using immunofluorescence and plaque reduction neutralisation test (PRNT), in which only 17 sera were confirmed positive. This corresponds to a prevalence of 6.8 per 1,000 sera (95% CI: 4.0–10.9). In a case-control study that matched each of the 17 PRNT-positive sera with four negative sera with the same date of donation and same donation centre, we did not find a significant association with age and sex of the donor; donors who worked mainly outdoors were significantly more at risk to have a positive PRNT for WNV.
authors: Lazio Sanita - Agenzia di Sanita Pubblica (Public Health Agency), Rome, Italy. pezzotti@asplazio.it
authors: P
authors: P
authors: Pezzotti
authors: C
authors: C
authors: Piovesan
authors: L
authors: L
authors: Barzon
authors: R
authors: R
authors: Cusinato
authors: M
authors: M
authors: Cattai
authors: M
authors: M
authors: Pacenti
authors: A
authors: A
authors: Piazza
authors: E
authors: E
authors: Franchin
authors: S
authors: S
authors: Pagni
authors: S
authors: S
authors: Bressan
authors: T
authors: T
authors: Martello
authors: R
authors: R
authors: Potenza
authors: C
authors: C
authors: Scipioni
authors: R
authors: R
authors: Ammendola
authors: A
authors: A
authors: Breda
authors: G
authors: G
authors: Palu
authors: F
authors: F
authors: Russo
authors: G
authors: G
authors: Rezza
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006462:Hemolytic Plaque Technique; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D014901:West Nile Fever / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D014902:West Nile virus / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M