Hantavirus is a less common, but often deadly illness. Awareness and prevention are the best defenses.

Deer mice are the most common carriers of hantavirus.
(Photo by Melvin Zettl, Unsplash)

Not every cautionary tale about diseases spread by critters is limited to vector-carriers like ticks and mosquitoes. Rodents also spread some less-discussed but equally deadly illnesses, like hantavirus, which is most often transmitted to humans by deer mice.

The recent illnesses and deaths aboard an Atlantic cruise ship serve as a sobering reminder that while deer mice are little and perceived as "cute," they can spread hantavirus. "Six people on board a cruise ship were affected by suspected cases of hantavirus, and three died," reports Evan Bush of NBC News. The disease is "relatively rare but devastating threat without a vaccine, treatment or cure. . . . More than 890 cases of hantavirus were reported nationwide from 1993 to 2023."

Hantavirus can be transmitted to humans through contact with saliva, droppings or urine of infected rodents. Bush explains, "People tend to get hantavirus when they disturb droppings or urine from mice in the dusty corners of barns, cabins or outbuildings near forested land, including during cleaning."

The disease is most common in the southwestern U.S., where deer mice are found. But that doesn't mean it can't be found elsewhere in the country, Bush reports. Human to human transmission is also possible.

Initially, hantavirus presents as a flu-like illness, which can be difficult to differentiate from Covid or other forms of influenza that cause coughing, fatigue and body aches. But it can develop into an aggressive respiratory disease. 

Dr. Jeff Duchin, an expert on hantavirus, told Bush, "The fatal, rapidly progressive pulmonary illness can come on very quickly, in hours. That, itself, can become fatal on a very short timeline." The disease weakens blood vessels, allowing fluid to fill the lungs, which eventually causes death.

Since there is no vaccine or medicine to treat hantavirus, prevention is the best protection. When disinfecting a rodent infestation, Erin Phipps, a public health veterinarian in New Mexico, recommended "wearing gloves, using N95 respirator, opening windows and relying on disinfectants," Bush reports. 

Phipps told Bush, "Never sweep up or vacuum mouse droppings, since this can spread particles up into the air."