RIVERSIDE - Confirmation that mice trapped west of Beaumont tested positive for the potentially deadly hantavirus prompted Riverside County health officials today to remind residents to take precautions in places inhabited by rodents.

According to the Department of Environmental Health, three deer and western harvest mice snared in January in the Norton Younglove Preserve, between San Timoteo Canyon Road and state Route 60, were confirmed as carriers of hantavirus.

The pathogen can lead to a severe and potentially fatal respiratory infection in humans called hantavirus pulmonary syndrome, or HPS.

County officials stopped short of issuing a health alert, saying the discovery of the infected rodents was not unusual. Thirty-one other mice netted in the same area did not test positive. Between 2002 and 2012, roughly 10 percent of rodents collected in Riverside County were found to be hantavirus carriers, officials said.

Hantavirus is transmitted through rodent feces and urine. Mice do not exhibit symptoms of being sick, making identification of infected creatures difficult, according to the Department of Environmental Health.

Residents are advised Advertisement

[ Metalography ] to avoid stirring up dust and debris when cleaning places where rodents have left droppings and to follow these additional recommendations:

-- ventilate rodent-infested places the night before cleaning them;

-- apply household disinfectants liberally in rodent nesting areas;

-- use rubber gloves while cleaning;

-- use a mop or sponge -- not a vacuum cleaner or broom -- to clean;

-- double-bag dead rodents and the waste cleared out of infested areas; and

-- wash hands with gloves still on, then wash again after removing them.

Warning signs of HPS include headache, fever, muscle aches, vomiting and abdominal pain. If untreated, respiratory failure can ensue.

Fifty-six hantavirus cases have been reported in California -- though none in Riverside County -- since 1980. Twenty were fatal. One of the worst- known cases of an outbreak occurred in the Four Corners region of the desert southwest in 1993. More than 30 people died over the course of a year.

Anyone with questions or concerns can contact the Department of Environmental Health at (951) 766-9454.