Concerns Over West Nile Virus Remain Low Despite Surge in Cases

As of September 23, 2025, the United States has reported over 1,100 human cases of West Nile virus across 42 states, marking a 40% increase compared to typical figures for this time of year, according to the U.S. Centers for Disease Control and Prevention (CDC). This includes nearly 750 instances of the more severe neuroinvasive form of the virus, which can affect the brain. Colorado leads the states with the highest number of cases, reporting 220 infections.

The CDC attributes the uptick in cases to climatic changes that are extending the traditional mosquito season, which generally lasts through October. Although many individuals infected with West Nile virus show no symptoms, others may experience a range of issues from mild, flu-like symptoms to severe conditions that require hospitalization and can potentially be fatal.

Interestingly, despite the rising number of reported cases, public concern regarding West Nile virus remains significantly low. A recent survey conducted by the Annenberg Public Policy Center (APPC) at the University of Pennsylvania found that only 15% of approximately 1,700 U.S. adults surveyed expressed worry about contracting West Nile virus or dengue fever within the next three months. This statistic reflects no change from a similar survey conducted in September 2024.

Ken Winneg, managing director of survey research at APPC, emphasized the importance of public awareness regarding the virus. He suggested that as the number of cases climbs and the mosquito season extends, there should be a heightened awareness and proactive approach to mosquito control and bite prevention.

According to the APPC survey, the following key insights were revealed:

• While 75% of respondents understand that West Nile and dengue fever can be contracted through mosquito bites, nearly half (48%) are unsure about the specific symptoms associated with West Nile virus.
• A significant gap in knowledge exists regarding the proper application of mosquito repellent. Only 14% of adults correctly know not to apply repellent under clothing, and only 33% are aware that sunscreen should be applied first and allowed to dry before applying repellent.
• Despite the awareness of the risks, 81% of participants recognize that preventing mosquito bites is the most effective defense against these illnesses.

When questioned about the symptoms of West Nile virus, many respondents struggled to identify them accurately. Fever was recognized by 45% as a potential symptom, while other symptoms such as muscle pain (41%), headache (38%), nausea (33%), and rash (23%) were also mentioned. Alarmingly, 31% of participants incorrectly identified dizziness as a symptom.

There is currently no antiviral treatment available for either West Nile virus or dengue fever, and only 22% of survey respondents were aware of this fact. Most either did not know (61%) or mistakenly believed that a treatment exists (17%).

The CDC recommends several preventative measures to minimize the risk of mosquito bites, including:

• Removing standing water around homes.
• Avoiding activities that may attract mosquitoes.
• Using insect repellent properly on exposed skin.
• Wearing protective clothing when outdoors.

As the mosquito season continues, it is crucial for individuals to stay informed about preventive measures, especially given the potential severity of West Nile virus. Public health officials urge the population to take proactive steps in controlling mosquito populations and protecting themselves from bites.