Have a look at the essential concepts, terms and events from the static and current parts of UPSC-CSE.
Word: West Nile virus
Subject: Science (Health)
Why is West Nile virus in the news?
Kerala Health Department is on alert after a 47-year-old man from Thrissur died due to West Nile virus.
Earlier in 2019 too, a six-year-old child died in Malappuram district due to the same infection.
The virus was first reported in Alappuzha district of the state in 2006 and then in Ernakulam in 2011.
What is West Nile Virus?
West Nile virus is a mosquito-borne, single-stranded RNA virus.
According to WHO, it is “a member of the Flavivirus genus and belongs to the Japanese encephalitis antigenic complex of the Flaviviridae family”.
It is a flavivirus related to the virus that causes St. Louis encephalitis, Japanese encephalitis and yellow fever.
How is West Nile Virus (WNV) spread?
– Culex species of mosquitoes act as major carriers for transmission. It is spread between humans and animals by infected mosquitoes, and between birds, which are reservoir hosts of the virus.
According to WHO, mosquitoes get infected by eating infected birds, which spread the virus in their blood for a few days. The virus eventually moves into the mosquito’s salivary glands. During a subsequent blood meal (when mosquitoes bite), the virus can be injected into humans and animals, where it can multiply and possibly cause disease.
WNV can also be spread through blood transfusions, from an infected mother to her child, or through exposure to the virus in laboratories.
How can WNV not spread?
It is not known to spread through contact with infected humans or animals.
– According to the US Centers for Disease Control and Prevention (CDC), it “does not spread by eating infected animals, including birds. Always follow directions for thoroughly cooking meat”.
What is the incubation period of WNV?
The incubation period for WNV disease is usually 2 to 6 days, but it can range from 2 to 14 days, and several weeks in immunocompromised people.
What are the symptoms of WNV?
The disease is asymptomatic in 80% of infected people. The rest develop what is called West Nile fever or severe West Nile disease.
– In 20% of these cases, symptoms include fever, headache, fatigue, body aches, nausea, rash, and swollen glands.
How dangerous can WNV be?
Severe infection can lead to neuro-invasive diseases such as West Nile encephalitis or meningitis or West Nile poliomyelitis or acute flaccid paralysis.
-WNV-associated Guillain-Barré syndrome and radiculopathy have also been reported.
It usually becomes fatal in individuals with co-morbidities and in immune-compromised individuals (eg transplant patients).
points to ponder: What is the treatment for West Nile Virus? Where are the cases found in India?