It’s that time of year again. Spring cleaning. If you’re lucky, your spring-cleaning soundtrack will include the new arrival of birdsong accompanied by the host of wild critters whose presence accompany nature’s reawakening. However, some of the cute little rodents carry a virus that is very dangerous to humans – hantavirus.
Hantavirus is named after its discovery near the Hantaan river in South Korea in 1978. However, it was first recognized in the southwestern United States in May of 1993 during an outbreak in the Four Corners. An investigation of that outbreak later identified the deer mouse as the main local reservoir for the disease. Originally named Muerto Canyon virus, the specific strain of hantavirus in the Four Corners was later named Sin Nombre virus.
This virus causes a serious, sometimes fatal, respiratory condition known as Hantavirus Pulmonary Syndrome.
Hantavirus is transmitted through exposure to fresh urine, droppings or saliva from infected rodents. A person may become exposed when breathing in the virus, usually when droppings or urine containing the virus are stirred up and the virus enters the air as mist or dust.
Most commonly, exposure occurs during cleaning or exploration of enclosed areas that house mice and contain mouse droppings. Examples includes homes, cabins, sheds and abandoned or stored vehicles. Deer mice are common in the Four Corners and often seek shelter in these enclosed spaces. While active in the area each year, deer mice populations have been known to increase when a period of moisture follows drought.
To date, there have been five reported cases of Hantavirus Pulmonary Syndrome so far in 2023.
Early symptoms of hantavirus infection, which may occur from one to eight weeks after exposure, can include fever, tiredness and muscle aches – especially in the larger muscles near the back, hips, thighs and shoulders. This may be accompanied by flu-like symptoms such as headaches, chills or abdominal complaints, such as nausea and vomiting.
Respiratory symptoms typically occur four to ten days later and include cough, chest discomfort, and breathing difficulty. Almost four in 10 persons with Hantavirus Pulmonary Virus die from the disease.
To date, there is no treatment for hantavirus infection other than supportive care, so prevention and early recognition are key. Closed spaces should be aired out before entry and efforts should be undertaken to eliminate mouse populations by sealing up such spaces and trapping mice until they are gone. Rodent droppings should never be swept up. Nests and droppings should be soaked with a 10% bleach solution before cleaning them up.
Persons experiencing symptoms of hantavirus infection should seek immediate medical attention, as early recognition and supportive care can improve outcomes.
Dr. Matthew A. Clark, a board-certified physician in internal medicine and pediatrics, works for the Indian Health Service.
