HELENA — A second Montanan has become ill with the potentially fatal hantavirus within the last week, and state health officials are calling the two cases unusual but not alarming.
A man from Beaverhead County was released from Barrett Hospital and Health Care in Dillon this week and is recovering from the virus; a young woman from Cascade County died from the disease last week.
Hantavirus pulmonary syndrome is an airborne virus spread through human contact with rodent droppings, urine and saliva. The national fatality rate from the disease is 38 percent, while Montana's death rate is 22 percent.
The Dillon case marks the third time the virus has surfaced in Beaverhead County since 1998. No one from the county has died from the virus.
"These cases seem to be sporadic, isolated events," said Jim Murphy, health specialist at the state medical lab in Helena. "Hopefully, this isn't an indication of how the rest of the year is going to go."
Montana has confirmed 19 cases of the virus since it surfaced in New Mexico in 1993; four afflicted Montanans have died. The deaths occurred in Cascade, Glacier and Philips counties.
The No. 1 cause of the disease is prolonged human exposure to rodent droppings and mice nests in homes, Murphy said. Deer mice are the main carriers of the disease in Montana and up to 15 percent of the state's deer mice population carries it.
The symptoms of hantavirus are similar to the flu. Sufferers experience headaches, muscle aches and shortness of breath. Symptoms usually surface two to three weeks after exposure, but the disease can live in the body up to 45 days after exposure.
The unusually wet weather this spring is bringing out the deer mice, said Sue Hansen, public health nurse in Beaverhead County. Preventing the disease is key, she said.
Rodent nests or droppings should be soaked with a disinfectant, such as a bleach and water solution, before they are removed. Handlers should wear rubber gloves and take caution not to sweep or vacuum any of the dust from the area into the air.
Once the rodent nests and droppings are removed, the home must be sealed against future rodent invasions, Hansen said.
State health officials said the disease is not a growing problem in Montana.
"These are rare events, especially when you consider how many farmers and ranchers are kicking mice out of their way," Murphy said.