Published on: September 1, 2021



What is in news : Russia issued a warning about the possibility of rise in cases of West Nile Virus  infections this autumn because mild temperatures and heavy precipitation are the favourable circumstances for mosquitos carrying the virus.

What is West Nile virus:

  • Single-stranded RNA virus causing West Nile fever
  • Member of family Flaviviridae(which also comprises the Zika virus, dengue virus, yellow fever virus)
  • Primarily transmitted through mosquitoes and mostly by species of Culex
  • Primary hosts are birds
  • Genetically related to the Japanese encephalitis family
  • Humans and horses both exhibit disease symptoms from this virus.
  • First human case of the disease was reported in 1937 in Uganda and now it is the leading cause of mosquito-borne disease in continental United States.


  • Usually have no symptoms or mild symptoms.
  • Fever, headache, body aches, skin rash, and swollen lymph glands
  • Last a few days to several weeks, and usually go away on their own.
  • If enters the brain, it can be life-threatening. It may cause inflammation of the brain, called encephalitis, or inflammation of the tissue that surrounds the brain and spinal cord, called meningitis.


  • No specific vaccines or treatments
  • The best way to avoid is to prevent mosquito bites.
  • Treatment is supportive for patients with neuro-invasive West Nile virus, often involving hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections.