West Nile Virus Seroprevalence in Manisa Province: A Population-based Study

Objective: West Nile Virus (WNV), which causes widespread outbreaks in different parts of the world, is a risk to public health in Turkey, too. Community-based study data are needed to identify measures against possible outbreaks. This study aimed to determine the seroprevalence of community-based WNV in Manisa and to investigate the relationship between sociodemographic and socioeconomic variables.

Methods: We included individuals older than two years of age (N=1,317,917) registered in the Manisa Province Family Medicine Information System. Selected participants (n=1233) were determined by a simple random sampling method. Specific IgG antibodies against WNV were investigated in serum samples using a commercial ELISA test (Euroimmun, Germany). The relationship between age, gender, location, education and income level, occupation, population density, altitude, the location of the toilet in the house, and the presence of hypertension, diabetes mellitus and cardiovascular disease variables were analyzed by chi-square, Fisher's exact test and t-test. Adjusted odds ratio (OR) with95% confidence interval (CI) for each variable were calculated by the logistic regression method to explain potential risks.

Results: WNV IgG antibodies were detected in 47 (3.8%) sera samples by ELISA. Seroprevalence was significantly correlated with independent variables of advanced age, presence of hypertension, diabetes mellitus and cardiovascular disease, low level of education and income, living in low altitude areas and the location of the toilet. In multivariate analysis; age (every one-year increase) (OR:1.05; 95% CI:1.02-1.07; p <0.001), equivalent annual income per capita below 3265 TL (OR:3.21; 95% CI: 1.53-6.73; p=0.002), and living areas below 132 meters altitude (OR=3.21; 95% CI 1.26-8.15; p=0.014) were found to be the risk factors for WNV seropositivity.

Conclusion: In Manisa province, WNV IgG seroprevalence was detected as 3.8% with ELISA method. Older age, low income and living in regions with a low altitude were found to be associated with increased seropositivity significantly.