2025 Vector-Borne Disease Season: What’s Emerging Across the U.S.

November 3, 2025Insect Repellent & Vector-Borne Disease4 min read

By: Richard Rich

Mosquito season stretched late into the fall of 2025. As a result, public-health agencies reported an unusually active year for several vector-borne diseases. These are illnesses spread by mosquitoes and ticks. So R&R Lotion took a closer look at what is happening across the country and how you can protect yourself, your team and your community.

West Nile Virus: Still the Leading Vector-Borne Disease Threat

West Nile Virus (WNV) still leads mosquito surveillance in the U.S. In fact, this year’s numbers are tracking higher than normal. The CDC has confirmed more than 700 human cases across 39 states. Nearly two-thirds of them are severe, neuroinvasive infections.

Meanwhile, local health departments from Texas to Pennsylvania are finding record numbers of positive mosquito traps:

Hays County, TX recently confirmed WNV in mosquito pools for the first time this season.
Luzerne County, PA found more than double the number of positive traps compared with 2023.

The virus thrives in warm, stagnant water left after summer rains. Also, many regions are seeing warm early-fall weather. Because of that, mosquitoes and the risk they bring linger well past Labor Day.

Chikungunya Makes a Rare U.S. Appearance

In October 2025, New York State confirmed its first locally acquired chikungunya case in six years. The patient had not traveled abroad. This suggests that the Aedes mosquitoes that carry the virus are now settled enough to allow limited local spread.

The CDC stresses that the risk remains low. Even so, the case points to a broader reality. Climate shifts and global travel are expanding the reach of mosquito species once limited to the tropics.

Other Vector-Borne Diseases to Watch

Beyond West Nile and chikungunya, surveillance networks have also picked up several other mosquito-borne and tick-borne infections:

Dengue: Dozens of U.S. travel-associated cases, plus isolated local cases in Florida and Texas.
Eastern Equine Encephalitis (EEE): Detected in horses in Michigan, which signals the virus is circulating in the region.
Jamestown Canyon and St. Louis Encephalitis: Positive mosquito pools in several Midwestern states.
Tick-borne illnesses: Lyme disease and Rocky Mountain Spotted Fever remain widespread through autumn. This year’s wet spring created lush tick habitat, too.

Taken together, these reports point to a longer, more complex vector season. For that reason, both individuals and employers should rethink protection as a year-round habit.

Bite Protection: The Human Factor Matters

There are no vaccines or antiviral treatments for most of these viruses. So avoiding bites still comes down to daily habits at home and at work:

First, remove standing water around homes, jobsites and storage areas.
Next, wear long sleeves and light-colored clothing outdoors at dawn and dusk.
Finally, use a repellent with an EPA-registered active ingredient and apply it as the label directs.

The R&R Lotion Response: IC Insect Repellent Lotion and Spray

R&R Lotion developed its IC Insect Repellent line for exactly this kind of season. Each product is made with IR3535®, an EPA-registered repellent active that is gentle on skin. In addition, our lotion and spray help repel mosquitoes, ticks and biting flies. They also go on without a strong chemical odor.

Why IR3535 Matters

Broad bite protection: Repels mosquitoes, ticks and biting flies.
Skin-friendly formula: Built on R&R Lotion’s long history of industrial-grade skin-care products.
Workplace-ready packaging: Made for safety programs that value both protection and comfort.

Whether you look after outdoor crews, travelers or families, IC Insect Repellent Lotion and Spray add a reliable layer of bite protection in an unpredictable vector season.

Stay Protected, Stay Productive

Vector-borne disease risks will keep changing as climates and ecosystems shift. Still, this year’s rise in mosquito and tick activity sends one simple message: avoiding bites matters.

Going forward, R&R Lotion will keep sharing science-based updates. We will also keep making products that help keep your people comfortable and protected, because healthy skin and a healthy workforce go hand in hand.