Ecological Niche Modeling of West Nile Virus Vector in Northwest of Iran

OBJECTIVES: West Nile virus (WNV) is a microorganism and the leading cause of the spread of fatal diseases in horses, birds, and humans. The etiologic agent of West Nile fever belongs to the genus Flavivirus that is transmitted by Culex mosquitoes in Iran and throughout the world. We aimed to evaluate the distribution of WNV vectors in northwest of Iran ecological niche modeling. METHODS: This cross-sectional study was conducted in Ardabil province in one year, from January to December with the samples captured from May to November 2017. Forty-five locations from all 10 counties of the province were selected randomly to determine the seasonal activity of mosquitoes. Larval collection was carried out twice a month. MaxEnt version 3.3, ArcMap 10.3 software, jackknife, and crew methods were used to determine the impact of climatic change and environmental factors on the distribution of mosquito species. RESULTS: A total of 2000 larva were collected, 1789 (89.5%) of which were Culex larvae. Seven species of Culex genus were identified, including Culex pipiens, Cx. modestus, Cx. theileri, Cx. hortensis, Cx. perexiguus, Cx. tritaeniorhynchus, and Cx. mimeticus. Two important ecological niche areas were identified in the north and south of the province. The annual temperature and rainfall in the cold seasons were the most important factors affecting the distribution of Culex species larva. Cx. pipiens was identified as the main vector of WNV vectors with high frequency in Ardabil province. CONCLUSIONS: Two large areas were found as the ecological niches of larvae of these species. It is recommended that additional investigations be carried out on infection in adult female Cx. pipiens and its hosts in these areas.