Health Alert in Kerala as Five West Nile Cases Reported

The Kerala government’s health department has confirmed five cases of West Nile fever in the state's three districts. As a precaution, State Health Minister Veena George has ordered all district health authorities to be vigilant and to take mosquito control measures by stepping up pre-monsoon cleaning drives and surveillance activities. West Nile fever is caused in humans infected with West Nile Virus.

West Nile Virus Case in Kerala 

According to the Kerala health department, cases of West Nile Fever have been reported from Kozhikode, Malappuram and Thrissur districts.

Of the five reported cases, four persons have recovered, and one patient is under observation.

The first case of West Nile fever was detected in Kerala in 2011. The first death due to West Nile Virus was reported in 2022 when a 47-year-old man from the Thrissur district died of West Nile viral infection,

What is West Nile Virus fever? 

• According to the World Health Organisation (WHO), the first case of West Nile Virus was reported in the West Nile district of Uganda in 1937, hence the name. 
• The virus was later found in birds in the Nile Delta region in 1953. Birds are considered to be the natural host of the West Nile Virus.
• Migratory birds have spread the virus worldwide. According to the WHO, West Nile cases have been found in countries on major bird migration routes.
• West Nile virus cases have been reported throughout Africa, parts of Europe, West Asia, Australia, and the American continents, from Canada to Venezuela.
• West Nile Virus is a member of the flavivirus genus. 

Transmission of the West Nile Virus 

• The human infection is mostly due to the bites of infected mosquitoes. Culex species of mosquitoes are the main carriers of the virus. Mosquitoes by feeding on the infected birds become infected with the virus.
• The Virus can also infect animals; many such cases have been reported in horses.
• The virus can spread from infected animals to humans either through contact with them or exposure to their blood or other tissues. 
• Human infections have also occurred through organ transplants, blood transfusions and breast milk, but such incidences are very low.
• No human-to-human transmission of the West Nile Virus has been reported so far.

Health issues due to West Nile Virus infection 

• Serious cases of West Nile virus infection can cause fatal neurological disease in humans. 
• In around 80 per cent of the cases, there are no symptoms of fever. However, in around 20 per cent of the cases, the patient can develop severe fever, headache, tiredness, body aches, nausea, and vomiting.
• In very serious cases, it could lead to neurological disease, such as West Nile encephalitis meningitis or West Nile poliomyelitis.
• No Vaccine has been developed for humans against the West Nile Virus however, vaccines are available for use in horses.