West Nile virus infections in the U.S. have surged to their highest numbers for this time of year since 2004, according to the CDC. While most people won’t experience symptoms, experts explain why protecting yourself from mosquitoes remains important.
- 80% of infected people show no symptoms
- Severe illness occurs in less than 1% of cases
- Prevention includes repellent and eliminating standing water
What happened
West Nile virus cases have increased sharply in the U.S. this year, with the majority of infections reported during August and September. This marks the highest count for this point in the year since 2004, as confirmed by Centers for Disease Control and Prevention (CDC) data. Environmental factors such as warmer temperatures, prolonged mosquito seasons, and heavy rainfall have created ideal conditions for mosquitoes to thrive and spread the virus.
Communities with poor drainage, standing water in neglected areas, and underfunded mosquito control programs have seen more cases. The virus is transmitted through mosquito bites and cannot spread from person to person. All residents or visitors in areas where West Nile virus is active are at potential risk of infection.
Why it feels good
Despite the rise in cases, there is reassuring news for most people. About 80% of those infected do not develop any symptoms, as a healthy immune system often eliminates the virus before illness can occur. For the 20% who do develop symptoms, these are typically mild and include fever, headache, body aches, and rash.
Severe illness is very rare, affecting less than 1% of infected individuals, and often occurs in older adults or people with certain medical conditions. Even among those with severe disease affecting the nervous system, fatalities are uncommon, occurring in roughly 10% of those cases—amounting to a very small overall risk.
What to enjoy or watch next
Prevention efforts remain the best way to stay safe during mosquito season. Experts recommend using insect repellent, wearing long sleeves and pants during dawn and dusk when mosquitoes are most active, and removing any standing water around homes to reduce mosquito breeding grounds. Installing window and door screens also helps keep mosquitoes out.
Communities can also support mosquito control programs to lower the risk locally. If you notice symptoms like high fever, stiff neck, confusion, or muscle weakness, seek medical attention promptly. Meanwhile, staying informed about local mosquito activity and practicing protective measures means you can enjoy outdoor time with greater peace of mind.