West Nile Virus (WNV) is one of the most widespread mosquito-borne viral diseases in the world. It can cause serious illness in humans, birds, horses, and other animals. As summer approaches, it’s crucial to be aware of this virus, understand its symptoms, learn about the available treatments, and recognize its global impact. This knowledge is especially important as cases of West Nile typically occur during mosquito season.

Symptoms of West Nile Virus

While most individuals infected with WNV remain asymptomatic, about 20% develop mild symptoms. These symptoms include fever, headache, body aches, fatigue, skin rash, and swollen lymph nodes. However, in approximately 1% of cases, severe illness occurs, affecting the central nervous system. This can result in encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes surrounding the brain and spinal cord). Severe cases can be fatal, with the case-fatality rate significantly higher in immunosuppressed individuals and those over 60 years old, reaching up to 30%.

Available Treatments

Currently, there are no vaccines to prevent or specific medicines to treat WNV. Supportive care focuses on symptom relief, including pain management, hydration, and hospitalization for severe cases. At LWNVIVAT, efforts are underway to develop a safe WNV vaccine that covers viral diversity and protects elderly individuals by promoting potent and long-lasting neutralizing humoral and T cell responses.

Global Spread and Impact

First identified in Uganda in 1937, WNV has since spread globally, affecting regions in North America, Europe, Asia, and Africa. The incidence of WNV varies annually and by region. In the United States, thousands of cases are reported each year, with peak transmission occurring in late summer and early fall. Europe has also seen an increase in outbreaks. In 2023 alone, 728 human cases of WNV infection were reported in Europe, with 709 locally acquired and 19 travel-associated.

Role of Climate Change in WNV Spread

Climate change is accelerating the spread of WNV. Warmer spring and summer temperatures create favorable conditions for the virus and its mosquito vectors. These conditions accelerate mosquito development, extend their breeding season, and increase their populations, thereby enhancing WNV transmission rates.

The Family of WNV

West Nile Virus (WNV) is a single-stranded RNA virus belonging to the Flaviviridae family and the Flavivirus genus. This genus also includes other notable viruses such as Zika, dengue, and yellow fever. Like most flaviviruses, WNV is an enveloped virus with icosahedral symmetry.

Understanding WNV, its symptoms, treatment options, and global impact is essential in minimizing its spread and mitigating health risks. As climate change continues to influence its transmission, awareness and preventive measures become even more critical.