In news- Russia has warned of a possible increase in West Nile virus infections this autumn as mild temperatures attributed to climate change could cause such diseases to become more widespread.
About West Nile virus-
- West Nile Virus (WNV) is a member of the flavivirus genus and belongs to the Japanese encephalitis antigenic complex of the family Flaviviridae.
- It was first isolated in a woman in the West Nile district of Uganda in 1937.
- It was identified in birds (crows and columbiformes) in the Nile delta region in 1953.
- Members of the crow family (Corvidae) are particularly susceptible, but the virus has been detected in dead and dying birds of more than 250 species.
- Outbreak sites are on major bird migratory routes.
- In its original range, WNV was prevalent throughout Africa, parts of Europe, Middle East, West Asia, and Australia.
- It is mainly transmitted through mosquito bites.
- It can lead to a fatal neurological disease in humans, although most people infected never develop any symptoms.
- Horses, just like humans, are “dead-end” hosts, meaning that while they become infected, they do not spread the infection.
- There are no vaccines to prevent or medications to treat West Nile virus in people and about 1 in 5 people who are infected develop a fever and other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash.
- About 1 in 150 people who are infected develop a severe illness affecting the central nervous system such as encephalitis or meningitis.
- People over 60 years of age are at greater risk for severe illness if they are infected.
- The virus may also be transmitted through contact with other infected animals, their blood, or other tissues.
- There is one reported case of transplacental (mother-to-child) WNV transmission.
- To date, no human-to-human transmission of WNV through casual contact has been documented.
- The incubation period is usually 3 to 14 days.
- Treatment is supportive for patients involving hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections and no vaccine is available for humans.