Lethality of West Nile virus strains in a mouse model

West Nile fever (WNF) is a viral infection caused by West Nile virus (WNV), a flavivirus of the Flaviviridae family. Virus circulates between mosquitoes and wild birds, but can infect other species, including humans. The first cases of West Nile fever were reported in Africa in the 1930s. Currently, WNV has a wide geographic range, which includes countries in Europe, Asia, Africa, Australia, and North and South America, where it periodically causes WNF outbreaks. The disease in human occurs with the development of fever, and in some cases ending up severe neurological complications. Studies of the virus in animal models demonstrate that virulence varies depending on the host species, the genotype of the virus, and the presence of substitutions in key viral proteins, even within the same genotype. These studies highlight the need for comparative studies of different WNV strains to evaluate the impact of amino acid substitutions on WNV pathogenesis. Analysis of key mutations and substitutions will allow the development of a safe and effective vaccine for the prevention of WNF.