Health officials with Public Health – Seattle & King County report a hantavirus case in an adult resident of southeast King County, who was hospitalized in December 2021 and is now recovering. The patient reported likely exposure to a mouse infestation.
Hantavirus can cause a rare but deadly disease called Hantavirus Pulmonary Syndrome (HPS). Hantaviruses are a group of viruses carried by rodents, and Sin Nombre virus is the type found in western North America.
HPS is rarely identified in Washington state, with only 45 cases reported since 1997, mostly in eastern Washington. Since 1997 there have been eight cases of HPS in King County.
In Washington state, hantavirus is carried only by deer mice. A person most often gets infected with hantavirus by breathing in the virus from activities that put people in contact with rodent droppings, urine, saliva, or nesting materials. Hantavirus spreads when dust that contains the virus is stirred up into the air, such as when people sweep or vacuum in rodent-infested areas. Less frequently, people get infected by touching their eyes, nose, or mouth after handling any contaminated rodent materials, or by being bitten by an infected rodent. Hantavirus is not spread person-to-person.
The illness starts one to six weeks after exposure with fever, headache, and muscle ache, and progresses rapidly to severe difficulty in breathing and, in some cases, death.