Environmental factors influencing the prevalence of Culex mosquitoes: An ERA-Interim approach.

Mosquitoes of the genus Culex act as vectors for the transmission of West Nile Virus (WNV) infection in humans. The factors which determine the spatial and temporal distribution of WNV in Culex mosquitoes are not well understood. Studies have reported associations between environmental factors, such as temperature, precipitation and the prevalence of West Nile virus in Culex mosquitoes. We investigated the association between environmental factors and the quantitative presence of Culex mosquitoes in a WNV prevalent area to identify environmental factors which may create conditions that favour the proliferation of Culex mosquitoes and thus increase the risk of WNV infection in humans. We also explored climate variability effects. We analysed data on numbers of Culex mosquitoes from 11 traps distributed in a region of Northern Greece over the years 2011 – 2013, a period where WNV infections in humans were notified in Greece including that region. Time series of environmental data of temperature, relative humidity, soil temperature, volumetric soil water layer, wind speed, and precipitation were determined utilising the ECMWF’s (European Centre for Medium-Range Weather Forecasts) -Re-Analysis (ERA-Interim) approach as it is used in atmospheric sciences where observational data are sparse allowing for a homogeneous set of data in time and space. Employing a regression model we identified associations between the above variables and the population of Culex mosquitoes. A clear relationship between the mean value anomalies over the last 30 years, defining climate, of almost all variables and the abundance of Culex could be shown. Similar associations were identified when the mean values of the variables were regressed with the population of Culex mosquitoes of the period 2011-2013. However, these associations found to differ in the case of climate anomalies and absolute values. Utilising the ERA-Interim approach for the assessment of the effects of environmental factors on the abundance of Culex mosquitoes at a regional scale it could be shown that factors other than temperature and precipitation may also affect mosquito abundance. The methodology used to capture climate conditions in a more complete temporal and spatial manner represents a valuable alternative when detailed observations are sparse or lack quality.

STILIANAKIS Nikolaos;  PETROLIAGKIS Thomas;  SYRRIS Vasileios;  PART Peter;  GEWEHR Sandra;  KALAITZOPOULOU Stella;  MOURELATOS Spiros; 

2014-10-20

European Society for Vector Ecology

JRC91282

https://publications.jrc.ec.europa.eu/repository/handle/JRC91282,