West Nile Virus

The West Nile Virus is a mosquito-borne, single-stranded RNA virus.
According to the WHO, it is “a member of the flavivirus genus and belongs to the Japanese Encephalitis antigenic complex of the family Flaviviridae”.

Transmission

Culex species of mosquitoes act as the principal vectors for transmission.
It is transmitted by infected mosquitoes between and among humans and animals, including birds, which are the reservoir host of the virus.
WNV can also spread through blood transfusion, from an infected mother to her child, or through exposure to the virus in laboratories.
It is not known to spread by contact with infected humans or animals.
Mosquitoes become infected when they feed on infected birds, which circulate the virus in their blood for a few days.
The virus eventually gets into the mosquito’s salivary glands.
During later blood meals (when mosquitoes bite), the virus may be injected into humans and animals, where it can multiply and possibly cause illness.
WNV outbreak sites are found along major bird migratory routes.

Symptoms

The disease is asymptomatic in 80% of the infected people. The rest develop what is called the West Nile fever or severe West Nile disease.
In these 20% cases, the symptoms include fever, headache, fatigue, body aches, nausea, rash, and swollen glands.
Severe infection can lead to encephalitis, meningitis, paralysis, and even death.
It usually turns fatal in persons with comorbidities and immuno-compromised persons (such as transplant patients).

Prevention

This vector-borne disease can be prevented by protecting one-self from mosquito bites.
Other steps are wearing clothing that acts as a barrier to exposure to bites, reducing breeding sites, covering water storage containers, eliminating puddles and drainage of places where water accumulates, eliminating unusable containers where water pools, and controlling garbage in yards and gardens.