Rising Tick-Borne Diseases: New Threats and Prevention

As temperatures rise, ticks are spreading unfamiliar diseases across the U.S., posing a health risk on par with Lyme disease. Dr. Natasha Wyndham Hanners, an infectious disease specialist, notes that reports of vector-borne illnesses are increasing. Climate changes, expanding habitats, and global travel contribute to this rise. Advanced diagnostics also help identify new pathogens.

Emerging Tick-Borne Illnesses

Scientists are uncovering how ticks are carrying new threats, such as orthonairoviruses, that elude the immune system. This shift is broadening the landscape of tick-borne diseases in the U.S.

Anaplasmosis

Anaplasmosis, a bacterial infection spread by blacklegged deer ticks, causes symptoms like fever and muscle aches but lacks Lyme disease’s bull’s-eye rash. Detection often requires a blood test.

Orthonairoviruses

This virus family includes Crimean-Congo hemorrhagic fever virus, a severe human pathogen. Research indicates these viruses can evade immune systems by altering immune signaling.

Nairoviruses

Nairoviruses, which include orthonairoviruses, are emerging as significant tick-borne threats. The Pacific Coast tick carries a newly identified nairovirus, PCTNV. While human infection from PCTNV isn’t confirmed, its immune evasion capabilities raise concerns.

Immune System Evasion

A study from the University of California, Riverside reveals how orthonairoviruses’ proteins disrupt immune signaling. This allows the virus to avoid detection. The study tested four nairovirus species, including PCTNV, highlighting the virus’s efficiency at bypassing human defenses.

Scott Pegan, the study’s lead author, emphasizes the importance of understanding tick types. Some carry diseases beyond known threats. More research is needed to confirm human exposure to PCTNV.

Spreading Threats

Anaplasmosis is spreading, similar to Lyme disease, but without the rash, making detection harder. Craig Bober, a primary care physician, warns that deer ticks also transmit babesiosis. Symptoms overlap with Lyme disease, necessitating blood tests for treatment guidance.

The Asian longhorned tick, identified in the U.S. in 2017, is another concern. It can reproduce without mating and is a carrier of SFTS. Although human infections are rare, the tick’s spread requires public awareness.

Prevention Tips

Experts recommend wearing long-sleeved clothing and using EPA-registered repellents with DEET, picaridin, or IR3535. Treat clothing with permethrin and shower within two hours after outdoor activities. Check your body for ticks, especially the scalp, underarms, and knees.

If a tick is attached, use fine-tipped tweezers to remove it, clean the bite, and consult a doctor if symptoms appear.

Gonzalez, D. S., et al. (2026). Insights into the Structure and Function of the OTU Protease Virulence Factors from Emerging Human Nairoviruses. ACS Infectious Diseases. https://doi.org/10.1021/acsinfecdis.6c00320.