Hantavirus Strikes Mammoth Resident

Current Situation –
A resident of Mammoth Lakes is in critical but stable condition today, after being flown to Reno last Monday with a probable case of hantavirus infection. Today we have received word that tests performed at the Nevada State Public Health Laboratory are positive, showing evidence of hantavirus infection. We expect that these will be confirmed shortly by the Viral and Rickettsial Disease Laboratory (VRDL) of the California Department of Public Health (CDPH) in Richmond.

Full credit for ensuring that the individual quickly received the highest level of care necessary to maximize the chances of survival go to an astute experienced local clinician at Mammoth Hospital.

An investigation into possible sources of the infection is being completed today. This includes inspections of personal residence and worksites, and is being done with the full cooperation of the patient, family, and employer. A total of 13 deer mice were trapped at various locations, and testing results will be available in about a week. This work is being completed by personnel from CDPH, assisted by local public health and environmental health staff. Once all results are in, then recommendations will be developed, with the goal of minimizing the future risk to family, co-workers, and the public from similar exposure and infection.

Background Information
Infections with hantavirus often increase as people begin to open up facilities that have been closed for the winter. Cleaning activities can disturb nesting materials contaminated with dried saliva, urine, or droppings from infected deer mice (Peromyscus maniculatus). The disturbed nesting materials become airborne and the air is inhaled causing an exposure to the virus. This exposure leads to a hantavirus infection. A person might also be infected with hantavirus if contaminated materials are directly introduced into broken skin or into the eyes or mouth.

Symptoms can begin 1-6 weeks after becoming infected with the virus. The illness typically starts with 3-5 days of “flu-like” symptoms including fever, sore muscles, headaches, nausea, vomiting, and fatigue. But remember, flu season is going away! Within a few days the illness rapidly progresses to severe shortness of breath. Early diagnosis of a hantavirus infection and immediate medical care increase the likelihood of a full recovery. However, mortality is at least 25%.
Individuals exposed to rodents or their waste who experience symptoms should immediately seek medical treatment and notify their provider that they have been around rodents or rodent wastes. Giving this information to your provider will help him or her to look closely for any rodent-carried disease, such as a hantavirus infection.

The best way to prevent hantavirus transmission is by controlling rodent populations in areas where you live and work.
Seal up cracks and gaps in buildings that are larger than 1/4 inch (5 mm), including window and door sills, under sinks around the pipes, in foundations, attics, and any rodent entry hole.

Trap indoor rats and mice with snap traps, and remove rodent food sources.
Keep food (including pet food) in rodent-proof containers.

If you find places where rodents have nested, or if you find rodent droppings or waste, follow these steps to help to prevent exposure to hantavirus while cleaning:
Ventilate spaces that have been closed for the winter for 30 minutes before entering.
Wear rubber or plastic gloves
Thoroughly spray/soak area with a disinfectant or mixture of bleach and water for 5 minutes to reduce dry dusty conditions in the area being cleaned  –  http://www.cdc.gov/rodents/cleaning/index.html
Wipe or mop the area with a sponge or paper towel (throw away items after use).
Wash hands thoroughly with soap and warm water after removing gloves.
Never sweep or vacuum in these areas as this can stir up dust and aerosolize the droppings.
For more information, go to:
www.cdc.gov/hantavirus/