Understanding Hantavirus and Health

Recently there has been a case of Hantavirus near our area (Grant County, WA) and I wanted to take the time to add some important facts that the newspaper has missed in their alert to the community. http://www.tri-cityherald.com/news/local/article211216904.html

So let’s talk about what the virus is and complete a FAQ style detailed report on what you need to know, so that you can protect you and your family from harm.

Source of the Virus:

Deer mice. Small, native rodents 5 to 8 inches long. Their fur resembles deer, dark on the back and white on the legs and underside. The tail is also dark on top and white underneath. (Major reservoir in western US). The last set of testing completed in WA State showed that16% of Deer Mice tested were positive.

How do humans get infected?

Exposure happens when infected deer mice or cotton rats shed the virus through their urine, saliva and feces. In order to get infected the dust containing the infected urine, feces and saliva must become airborne through vacuuming, sweeping or disturbing and then must be inhaled by a person. The other way to become infected is through touching your eyes, mouth or nose with infected hands.

Exposure to Hantavirus examples include:

• contaminated dust after disturbing or cleaning rodent droppings or nests,

• living or working in rodent-infested settings such as cabins, homes, barns, vehicles, outbuildings

• Handling of wild rodents without protection.

Where am I most likely to get exposed? Some of these include:

• Sweeping, vacuuming and disturbing the dust in a garage, barn, shed, car/truck and other ranch style buildings

• Trapping and studying mice

• Planting or harvesting field crops

• Occupying previously vacant dwellings

• Disturbing rodent-infested areas while hiking or camping

• Living in dwellings with a sizable indoor rodent population

• Using compressed air and dry sweeping to clean up an industrial area

• Handling grain contaminated with mouse droppings and urine

Who has the highest risk of contracting the virus?

Any man, woman or child who is around mice or rats that carry the harmful virus.Person to person spread has not occurred in the United States. The median age of cases in Washington State is 35 years (range 14–75 years). The death rate and median age of cases in Washington are similar to the national rates (1 in 3 people die).

What are the Symptoms?

1). Begin 1 to 6 weeks after inhaling the virus2).Symptoms are usually apparent within 2-6 days; “flu-like” illness including fever, sore muscles, headaches, nausea, vomiting, and fatigue.

2.5). Some people will start to feel better at this point and then a second wave of illness begins.3).Will cause shortness of breath due to fluid filled lungs as the disease gets worse. Hospital care is then required.4). It is usually a serious infection and about 1 out of 3 people diagnosed with HPS have died.

How to disinfect and stop the virus from becoming harmful?

Hantaviruses have been shown to be viable in the environment for 2 to 3 days at normal room temperature. Further, they are affected by conditions of environment such as temperature, humidity, and whether indoors or outdoors. Additionally, it is affected by the rodent’s diet –affects the chemistry of the urine and the Ultraviolet rays in sunlight kill Hantaviruses.

A half mask APR (with eye protection) or full face APR with P100s are said to effective as protective respiratory PPE and should be worn.

DO NOT use a vacuum of any type including one equipped with HEPA filters for cleaning dried rodent droppings or other dry debris. It blows air around and may create virus aerosols.

To clean and disinfect an area start with this procedure:

• Use rubber, latex, vinyl or nitrile gloves.

• Thoroughly wet contaminated areas with a bleach solution or household disinfectant (1 ½ cups bleach in 1 gallon water).

• Swipe up contaminated materials with damp towel then mop or sponge the area with bleach solution or disinfectant.

• Spray dead rodents with disinfectant then double-bag. Bury, burn or throw out rodent in appropriate waste disposal system.

• Disinfect gloves with disinfectant or soap and water before removing.

• Thoroughly wash hands with warm water & soap.

How do I prevent the virus?

It is very difficult to keep mice out of the home, garage and sheds. They can fit through any hole the size of a dime to get inside of a dwelling. Here are some pointers to help:

• Seal up building holes and gaps

• Do continuous or frequent trapping

• Clean up rodent food sources and nesting sites using appropriate gloves and respirator.

• Eliminate debris in and around buildings and grounds.

• Eliminate possible nesting sites –grass, woodpiles etc.

• Store food 12 to 15 inches off the floor and 12 to 18 inches away from the wall. Use rodent-proof --containers when possible.

• Screen dumpster drainage holes with hardware cloth

• Don't leave pet food out overnight

• Eliminate water sources available to rodents

Other Facts and Statistics:

In conclusion, it has to be an infected Deer mouse (16% tested are). It has to be fresh urine/feces/saliva read our “How to disinfect and stop the virus from becoming harmful?” above. It has to become disturbed and airborne somehow. You then have to inhale those particles. It can take up to

6 weeks to show symptoms. If you know that you have been around droppings and in 6 weeks you show symptoms get to a doctor and alert them of the potential infection. As you can see, a lot of stuff has to be in order for an infection. It’s always best to treat any mouse nests and excrement as infected and take precautions.

I hope this helped all of you and as always feel free to contact us for any questions.

Stay Safe,

Paul Nims, ASP, CHST, ASHM