West Nile Virus: A Silent Threat?

West Nile Virus (WNV), identified in Uganda in 1937, has spread globally, including North America and Europe. This virus primarily circulates between birds and mosquitoes, which then transmit it to humans and other mammals.

Most individuals infected with WNV do not develop symptoms. However, about 20% may experience illness, with severe cases leading to encephalitis or meningitis. Long-term effects can include muscle weakness and memory loss.

Human transmission occurs mainly through mosquito bites, though blood transfusions and organ transplants are also potential routes. There is no evidence of person-to-person spread through casual contact.

Treatment for WNV focuses on symptom relief, as no specific antiviral exists. Prevention strategies involve controlling mosquito populations and employing personal protective measures like insect repellent and protective clothing.

Outbreaks tend to occur during warmer months when mosquitoes are most active. In 2024, the United States reported nearly 1,800 cases and 164 deaths. Europe has also experienced outbreaks, with cases noted in Romania, Spain, and Italy. While the mosquito species is present in the UK, the risk remains very low.