Hantaviruses are single-stranded, enveloped, negative sense RNA viruses related in the Bunyaviridae family. They typically infect rodents but do not cause disease within their hosts. Humans are susceptible to infection of hantaviruses if they come into contact with rodent urine, saliva or feces.

Deer mouse/CDC
Deer mouse/CDC

Human infections of hantaviruses have almost exclusively been associated with the combination of human contact with rodent excrement. Of course transmission of the disease is not limited to contact with just feces or other excrement. While rare, if a rodent with the virus bites a human it can be transmitted that way. Some researchers also believe that humans can be infected if they touch something that has been contaminated with rodent urine, droppings or saliva then touch their own nose or mouth. It’s also believed that human can become ill if they have ingested food that has become contaminated.

Typically problems arise when Hantavirus develops into Hantavirus Pulmonary Syndrome (HPS).

Hantavirus became a predominant feature in the news during 2012 when 8 people became infected with the bacteria after visiting Yosemite National park. Three of those people passed away. California has seen 60 of the nation’s 639 hantavirus cases since 1993, the fourth highest number after New Mexico, Colorado and Arizona.


  1. Learn to Identify Rodents. The deer mouse is a concern due to the fact that over 10% are carriers of hantavirus. They are mostly found in rural areas and are native to the Pacific Northwest. An adult body is typically 3-4 inches in length with an additional 2-5 inches being added on for the tail. Coloring can vary from a pale gray to a deep reddish brown with a white underbelly. Deer mice like to feed on a variety of nuts, berries, seeds and other small animals such as insects, snails, slugs other dead mice or young birds.They typically feed at early dawn and again at dusk. They are commonly found to be nocturnal creatures. Their population numbers are large, so total elimination is incredibly difficult. However carriers are not limited to the deer mouse. The cotton rat, rice rat and white-footed mouse can be carriers as well.
  2. Consider Avoiding Bamboo in the Garden. The use of bamboo in landscaping has become incredibly popular with it being utilized for decor, live fencing and a privacy screen. The bamboo plant has a prolific seed production which can create a population boom among seed-eating deer mice. Richard Mack, an ecologist with WSU’s School of Biological Sciences, details how an outbreak of hantavirus could happen. While bamboo can have extremely intermittent flowering cycles they produce huge amounts of seed over as many as 18 months. During that time frame deer mice can undergo several reproductive cycles. When the mice have exhausted the seed supply they are likely to search out new food sources in or around human homes and other dwellings. As part of his study, Mack imported bamboo seed from China and fed it to dozens of laboratory-reared deer mice. “They loved it,” he said. “Generally, they preferred it to rat chow.”
  3. Remove Rodent Hiding Places/Make Entry Rodent Proof. Seal up cracks and crevices where rodents can enter, using spray foam around plumbing. Mice also enjoy wood or junk piles. Ensure these are a distance away from your residence. Furthermore, keep any vegetation located around your home well-trimmed. If you live in an area known for hantavirus exposure, consider hiring a professional exterminator to evaluate your home and possible risks.
  4. Cleaning and Food Storage. Proper food storage, in rodent-proof containers, is vital. Not only for regular food for your family but also pet food and any food that you may have on hand for livestock or birds. If you are cleaning out a facility such as a barn, outhouse or cabin ensure that you properly ventilate the structure and mop it, avoiding any sweeping or vacuuming as that can usher particles into the air. Even before mopping spray infested areas with a mixture of water and bleach to cut down the risk of dust. Consider the use of a dust mask.


Symptoms of HPS can start to show about 1-5 weeks after exposure. They are typically flu-like in behavior and one can experience tiredness, chills, dizziness, headaches, digestive problems, fever and aching muscles.

After 4-10 days of progression it can develop into cough, shortness of breath, fluid within the lungs and severe discomfort.


At this point in time, there is no cure for HPS. However, there are several treatment options, mostly non-pharmaceutical, available. Admission into an intensive care unit is common followed by oxygen therapy, breathing assistance and administering ribavirin to aid with kidneys.

The key is early treatment as it increases the chances for survival.

C.A. Newberry is a retired event coordinator with passion for continued learning and sharing life experiences. You can connect with her on Twitter.