The molecular biology of West Nile Virus: a new invader of the western hemisphere

Annu Rev Microbiol. 2002;56:371-402. doi: 10.1146/annurev.micro.56.012302.160654. Epub 2002 Jan 30.


West Nile virus (WNV) is a mosquito-borne flavivirus that primarily infects birds but occasionally also infects humans and horses. In recent years, the frequency of WNV outbreaks in humans has increased, and these outbreaks have been associated with a higher incidence of severe disease. In 1999, the geographical distribution of WNV expanded to the Western hemisphere. WNV has a positive strand RNA genome of about 11 kb that encodes a single polyprotein. WNV replicates in the cytoplasm of infected cells. Although there are still many questions to be answered, a large body of data on the molecular biology of WNV and other flaviviruses has already been obtained. Aspects of virion structure, the viral replication cycle, viral protein function, genome structure, conserved viral elements, host factors, virus-host interactions, and vaccines are discussed in this review.

Publication types

  • Review

MeSH terms

  • Animals
  • Base Sequence
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism
  • Humans
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • RNA, Viral / genetics
  • RNA, Viral / metabolism*
  • United States / epidemiology
  • Viral Proteins / metabolism
  • Virus Replication
  • West Nile Fever / epidemiology
  • West Nile virus / genetics*


  • RNA, Viral
  • Viral Proteins
  • DNA-Directed RNA Polymerases