Michigan has confirmed its first case of human Sin Nombre hantavirus, the state's health department said Monday.
A woman in Washtenaw County was recently hospitalized with a serious pulmonary illness from hantavirus, according to the Michigan Department of Health and Human Services, which said the woman "was likely exposed when cleaning an unoccupied dwelling that contained signs of an active rodent infestation."
Hantavirus infections, associated with contact with infected rodents, have caused hantavirus pulmonary syndrome, or HPS, in the United States since 1993. According to the health department, most cases of HPS are identified in adults, usually in the spring and summer.
There are no documented person-to-person cases of hantavirus transmission in the United States.
"HPS is caused by some strains of hantavirus and is a rare but severe and sometimes fatal respiratory disease that can occur one to five weeks after a person has exposure to fresh urine, droppings or saliva from infected rodents," said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health at MDHHS in a statement. "Anyone who comes into contact with rodents that carry hantavirus is at risk for HPS and healthcare providers with a suspect case of hantavirus should contact their local health department to report the case and discuss options for confirmatory testing."
Symptoms of HPS, which has a 40% fatality rate, at first can include fever, chills, body aches, headache and gastro-intestinal signs including nausea, vomiting, diarrhea and abdominal pain, according to the health department. Symptoms can progress to coughing and shortness of breath.
"Humans become infected when freshly dried materials contaminated by rodent excreta are disturbed and inhaled, get into breaks in the skin or on mucous membranes or when ingesting contaminated food or water," the health department said in a statement.
Rodent bites also can transmit hantavirus, according to the health department, which noted that "the highest risk of exposure takes place when entering or cleaning rodent-infested structures."
"We can prevent and reduce the risk of hantavirus infection by taking precautions and being alert to the possibility of it," said Dr. Juan Luis Marquez, medical director with Washtenaw County Health Department. "Use rubber, latex, vinyl or nitrile gloves when cleaning areas with rodent infestations, ventilate areas for at least 30 minutes before working, and make sure to wet areas thoroughly with a disinfectant or chlorine solution before cleaning."
Several hantaviruses that can infect people have been identified in the United States, each with a primary rodent host.
"The most important hantavirus in the U.S. that causes HPS is the Sin Nombre virus, which is spread by the deer mouse and white footed mouse."