West Nile virus

From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

West Nile virus is a mosquito-borne virus from the Flaviviridae, a viral family which also includes hepatitis C virus and dengue virus. West Nile virus virus mainly infects humans when they are bitten by a mosquito carrying the virus; but more rarely, cases of transmission of by blood transfusion and during organ transplants have been described.

West Nile virus is prevalent in many countries, including the USA, Australia, parts of Canada, parts of Europe, but not the UK, Ireland or New Zealand. In a study conducted in Connecticut, USA, the seroprevalence of West Nile virus in the general population was found to be 8.5% (this is the percentage of people who had previously caught this virus at some point in their lives).[1]

West Nile virus infection is asymptomatic in 80% of people who contract it; but in 20% of people, it produces acute symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. About 0.7% of people who are infected develop a severe illness targeting the central nervous system, such as encephalitis or meningitis.[2]

People infected with West Nile virus can afterwards experience long-term fatigue lasting years, and many such cases of fatigue satisfy the 1994 Fukuda criteria for ME/CFS.[3]

  1. Cahill, Megan E.; Yao, Yi; Nock, David; Armstrong, Philip M.; Andreadis, Theodore G.; Diuk-Wasser, Maria A.; Montgomery, Ruth R. "West Nile Virus Seroprevalence, Connecticut, USA, 2000–2014 - Volume 23, Number 4—April 2017 - Emerging Infectious Diseases journal - CDC". doi:10.3201/eid2304.161669. PMC 5367428. PMID 28322715. Cite journal requires |journal= (help)
  2. CDC (May 17, 2024). "West Nile: Symptoms, Diagnosis, & Treatment". West Nile Virus. Retrieved May 31, 2024.
  3. Garcia, Melissa N.; Hause, Anne M.; Walker, Christopher M.; Orange, Jordan S.; Hasbun, Rodrigo; Murray, Kristy O. (September 1, 2014). "Evaluation of Prolonged Fatigue Post–West Nile Virus Infection and Association of Fatigue with Elevated Antiviral and Proinflammatory Cytokines". Viral Immunology. 27 (7): 327–333. doi:10.1089/vim.2014.0035. ISSN 0882-8245. PMC 4150370. PMID 25062274.