West Nile virus seropositivity in Alanya, a coastal city in the Mediterranean region of Turkey

Abstract

BACKGROUND: West Nile virus (WNV)-related illness is a global health problem. Understanding the seropositivity rates and identifying the risk factors related to WNV in various animal species including humans is crucial for the implementation of effective prevention strategies. OBJECTIVES: Assess the rate of seropositivity and the risk factors associated with WNV seropositivity. DESIGN: Descriptive, cross-sectional SETTING: Microbiology and virology departments in a veterinary college PATIENTS AND METHODS: In a sample of healthy human participants in Alanya, located close to regions where WNV activity has been detected, anti-WNV IgG antibody detection was performed using enzyme-linked immunosorbent assays. The positive results were confirmed by virus neutralization tests (VNTs). The sample was compared with a second group of age- and gender-matched healthy subjects selected from a previous cross-sectional study. MAIN OUTCOME MEASURES: Determination of the seropositivity and risk factors that were associated with WNV in healthy humans. SAMPLE SIZE: 87 in current study; 356 in previous study. RESULTS: The first group of 87, which had a high risk of encountering vector mosquitoes, had a positivity rate of 8% (7/87), whereas positivity in the second group was 4.5% (16/356; P=.181). In the entire sample, the anti-WNV IgG antibody was positive in 23 out of 443 (5.2%) samples by the ELISA test. Among these 23 samples, ten were confirmed as positive using VNTs. Therefore, the WNV IgG seropositivity was 2.3% (10/442). Confirmed IgG seropositivity rates were higher among male (3.8%) than female participants (0.9%; P=.054) and among adults aged ≥45 years (4%) than those aged 18-44 years (0.8%; P=.048). CONCLUSION: This study highlights the presence of WNV infection in the research region. More comprehensive and multidisciplinary studies are required to increase our knowledge about this zoonotic infection including risk factors in line with the One Health approach. LIMITATIONS: Small sample size.