title: West Nile Virus Seroprevalence in the Greek Population in 2013: A Nationwide Cross-Sectional Survey.
abstract: 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.
authors.affiliation: Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Hadjichristodoulou
authors.affiliation: Department of Microbiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Spyros
authors.initials: S
authors.lastname: Pournaras
authors.affiliation: Department of Microbiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Mavrouli
authors.affiliation: Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.
authors.forename: Andriani
authors.initials: A
authors.lastname: Marka
authors.affiliation: Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.
authors.forename: Persefoni
authors.initials: P
authors.lastname: Tserkezou
authors.affiliation: Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece.
authors.forename: Agoritsa
authors.initials: A
authors.lastname: Baka
authors.affiliation: Laboratory of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Billinis
authors.affiliation: Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Katsioulis
authors.affiliation: Laboratory of Bacteriology, Parasitology, Zoonoses and Geogrphical Medicine, School of Medicine, University of Crete, Heraklion, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Psaroulaki
authors.affiliation: National Reference Center for Arboviruses, Department of Microbiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Papa
authors.affiliation: Laboratory of Entomology and Agricultural Zoology, School of Agricultural Sciences, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Volos, Greece.
authors.forename: Nikos
authors.initials: N
authors.lastname: Papadopoulos
authors.affiliation: Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece.
authors.forename: Zissis
authors.initials: Z
authors.lastname: Mamuris
authors.affiliation: Department of Microbiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Tsakris
authors.affiliation: Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece.
authors.forename: Jenny
authors.initials: J
authors.lastname: Kremastinou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005843:Geography; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D011159:Population Surveillance; D016036:Seroepidemiologic Studies; D014901:West Nile Fever / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D014902:West Nile virus / Q000276:immunology*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G