Understanding Hantavirus Risk and Prevention in the U.S.

Hantavirus remains a concern in the U.S., with recent attention due to a suspected case in Illinois. The virus, which can be fatal, is not linked to the MV Hondius cruise ship incident. The Andes strain responsible for deaths on the cruise ship is not found in North America.

In the U.S., the Sin Nombre virus variant is prevalent, mainly causing a severe lung condition. Rodent droppings, saliva, or urine can spread the virus to humans when particles enter the air. Arizona reports a high number of infections, but research identifies Virginia, Colorado, and Texas as emerging hotspots.

A study by Virginia Tech’s department of fish and wildlife conservation found that 15 types of rodents, including the deer mouse, host the virus. The study, published in Ecosphere, discovered six new rodent species as potential virus carriers, even in eastern regions where human cases are rare.

Luis Escobar, a Virginia Tech associate professor, points out Virginia as a hot spot for infected rodents. He pursued the study to understand animal-to-human virus transmission. Escobar warns of the risk due to some hantavirus strains having a 50% fatality rate, although widespread human-to-human transmission has not yet materialized.

Health authorities, including those from the World Health Organization and CDC, assure there is no indication of the hantavirus outbreak from the cruise ship becoming a pandemic. The Andes strain allows person-to-person transmission.

Reports of native U.S. hantavirus strains may rise with seasonal temperature increases. Dr. David Fitter of the CDC clarifies that routine cases differ from the outbreak on MV Hondius.

Escobar conducted his research by testing over 14,000 rodent blood samples from 2014-2019. The findings were shared in a CDC webinar focusing on new zoonotic threats. But, the presence of infected rodents does not guarantee human risk, emphasized by reported case numbers.

Since 1993, the CDC documented 890 hantavirus cases in the U.S., largely in the West, with Colorado and New Mexico each sharing over 120 cases. Arizona noted 92, and California had 79. Virginia had just two cases.

Approximately 35% of cases result in death. Awareness heightened when Betsy Arakawa’s death in March 2025 in New Mexico was linked to the virus, followed by three more deaths in California.

Los Alamos National Laboratory scientist Morgan Gorris shows that people in arid parts of the West are at increased risk. Dry air conditions allow rodent excrement to become airborne.

Gorris mentioned that human encroachment on rodent habitats increases infection risk. Stressed rodents may emit more viruses. Considering human, animal, and environmental interactions is vital when new diseases emerge.

How to Stay Safe from Hantavirus

The Illinois Department of Public Health is investigating a suspected hantavirus case following exposure to droppings. The patient is recovering from mild symptoms.

To reduce exposure risk, avoiding rodents and their droppings is key. Follow CDC guidelines when cleaning areas potentially exposed to rodents:

• Ventilate spaces by opening windows and doors for 30 minutes.
• Wear rubber or plastic gloves. While not explicitly recommended by the CDC, face masks are advised by Gorris.
• Avoid vacuuming or sweeping as it may aerosolize virus particles.
• Use a disinfectant or bleach solution (1 1/2 cups bleach per gallon of water) on urine and droppings and let soak for 5 minutes.
• Dispose of paper towels in covered garbage after cleaning.
• Disinfect hard surfaces thoroughly.
• Wash gloved hands first, then remove gloves and wash hands again with soap and water.