Abstract

Temperature Effects on the Basic Reproductive Number (R0) Of West Nile Virus, Based On Ecological Parameters: Endemic Vs. New Emergence Regions

Ariel Kushmaro, Tamara Awerbuch-Friedlander and Richard Levins

This study is to compare the Basic Reproduction Number of West Nile Virus in new-emergence regions to that of endemic ones, given that there is global warming and that R0 is a function of temperature sensitive parameters. It has been suggested that elevated temperatures via global warming affect the spread of vector-borne diseases. West Nile virus (WNV), an arbovirus, is transmitted to hosts mainly by mosquitoes of the genera Culex, and amplified through an enzootic cycle where mostly birds are the reservoir. Parameters involved in the amplification are temperature sensitive, thus we compare endemic to new-emergence regions for their susceptibility to West Nile Virus (WNV) based on their basic reproductive number (R0) which is a complex function of temperature dependent parameters. R0 for West Nile Virus indicates that new emergence regions are more vulnerable to outbreaks than endemic regions; that once introduced WNV will spread there more rapidly even in lower temperatures. The analysis suggests that the high susceptibility of birds in new emergence areas along with temperature sensitive parameters related to the vector, may explain in a complex manner, the higher WNV propagation in these regions, as it is happening in North and Central America.