Open AccessWest Nile Virus Seroprevalence in the Greek Population in 2013: A Nationwide Cross-Sectional Survey
Author(s) -
Christos Hadjichristodoulou,
Spyros Pournaras,
Maria Mavrouli,
Andriani Marka,
Persefoni Tserkezou,
A Baka,
Charalambos Billinis,
Antonios Katsioulis,
Anna Psaroulaki,
Anna Papa,
Nikos T. Papadopoulos,
Zissis Mamuris,
Athanasios Tsakris,
Jenny Kremastinou,
Malwest
Publication year - 2015
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0143803
Subject(s) - seroprevalence , cross sectional study , west nile virus , population , medicine , virology , environmental health , geography , virus , serology , immunology , pathology , antibody
Cases of West Nile Virus (WNV) disease were recorded for three consecutive years in Greece following the year 2010 outbreak. A cross-sectional serologic survey was conducted to estimate the WNV seroprevalence and assess the ratio of infection to neuroinvasive disease. A stratified left-over sampling methodology was used including age and residence strata. A total of 3,962 serum samples was collected and tested for WNV Immunoglobulin G (IgG) antibodies by Enzyme–Linked Immunosorbent Assay (ELISA). All positive samples were further tested by Plaque Reduction Neutralization Test (PRNT) and WNV Immunoglobulin M (IgM) antibodies. WNV IgG antibodies were detected in 82 samples and 61 were also positive in PRNT representing a weighted seroprevalence of 2.1% (95% C.I.: 1.7–2.6) and 1.5% (95% C.I.: 1.2–2.0), respectively. Multivariable analysis showed that seroprevalence was associated with age and residence. The overall ratio of neuroinvasive disease to infected persons was estimated at 1:376 (95% C.I.: 1:421–1:338), while the elderly people had the highest ratio. This nationwide study provided valuable data regarding the epidemiology of WNV in Greece based on the fact that elderly people have higher risk of being both infected and having severe disease.