Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States

Science. 1999 Dec 17;286(5448):2333-7. doi: 10.1126/science.286.5448.2333.


In late summer 1999, an outbreak of human encephalitis occurred in the northeastern United States that was concurrent with extensive mortality in crows (Corvus species) as well as the deaths of several exotic birds at a zoological park in the same area. Complete genome sequencing of a flavivirus isolated from the brain of a dead Chilean flamingo (Phoenicopterus chilensis), together with partial sequence analysis of envelope glycoprotein (E-glycoprotein) genes amplified from several other species including mosquitoes and two fatal human cases, revealed that West Nile (WN) virus circulated in natural transmission cycles and was responsible for the human disease. Antigenic mapping with E-glycoprotein-specific monoclonal antibodies and E-glycoprotein phylogenetic analysis confirmed these viruses as WN. This North American WN virus was most closely related to a WN virus isolated from a dead goose in Israel in 1998.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Viral / immunology
  • Base Sequence
  • Bird Diseases / epidemiology
  • Bird Diseases / virology
  • Birds / virology
  • Disease Outbreaks*
  • Encephalitis Viruses, Japanese / classification
  • Encephalitis Viruses, Japanese / genetics
  • Fluorescent Antibody Technique, Indirect
  • Genome, Viral
  • Humans
  • Molecular Sequence Data
  • New England / epidemiology
  • New York City / epidemiology
  • Phylogeny
  • Songbirds / virology
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / immunology
  • West Nile Fever / epidemiology*
  • West Nile Fever / veterinary
  • West Nile Fever / virology*
  • West Nile virus / classification*
  • West Nile virus / genetics*
  • West Nile virus / immunology
  • West Nile virus / isolation & purification


  • Antibodies, Monoclonal
  • Antibodies, Viral
  • Viral Envelope Proteins

Associated data

  • GENBANK/AF194117