Hantavirus Pulmonary Syndrome (HPS): what to do? Some tips

A person who breathes disturbed dust contaminated with Deer Mouse feces, urine, saliva or blood may contract Hantavirus. This problem can be encountered throughout the Southwest. What should you do if you discover that Deer Mice are present in your facility or your home, or if you accession items that are contaminated -- and what should you do to protect yourself?

Deer Mice are the rodents, in this area that are infected with Hantavirus that causes HPS. These rodents shed the virus in their urine, droppings and saliva. The virus is transmitted to humans when they breathe air contaminated with the virus.

This happens when rodent urine, droppings or nesting materials are stirred up, such as by sweeping an old storage shed infested with mice. When tiny droplets containing the virus get into the air, this process is known as "aerosolization."

The virus can also be spread if a rodent bites a human (rare), a person touches something that has been contaminated and then touches their nose or mouth, or if virus infected rodent urine, droppings or saliva contaminates food you eat. These possibilities demonstrate why disinfecting rodent infested areas are so important in preventing transmission of the virus.

The most sensible way to avoid contact with rodents is to prevent rodents from infesting the places where you live and work, and to follow safety precautions if you do stumble into a rodent-infested area.

· Keep a clean area, especially the kitchen and keep food in rodent-proof containers.

· Set covered bait stations following instructions carefully. Do not use a poison like D-Con® as the mouse may die elsewhere, possibly out of reach for disposal.

· Seal all entry holes 1/4 inch wide or wider with steel wool, cement, wire screening or other patching materials, inside and out.

· Clear all brush, grass and junk from around house foundations to eliminate a source of nesting materials.

· Use metal flashing around the base of wooden, earthen or adobe homes to provide a strong metal barrier and thus block entry.

· Elevate hay, woodpiles and garbage cans to eliminate possible nesting sites. If possible, locate them 100 feet or more from your home.

· Spray area with mixture of liquid bleach (such as Clorox®) and water (10% bleach solution) and let sit for a time.

· Put on rubber gloves, approved mask (3M model 8233 respirator) and wipe area putting rag and contents in a plastic bag after each wipe. Be careful not to create dust; that is why it is important to spray the area first.

· If a rodent is trapped in a sealed trap then put trap in plastic bag and dispose of it.

· Wear latex or heavy rubber gloves if possible, wear disposable coveralls, rubber boots, and safety goggles.

· If the Hantavirus occurs naturally in your area, you should wear a respirator mask with a HEPA (high-efficiency particulate air filters -3M model 8233), and be trained on how to use it.

· If the area is a large area than the use of a hazardous materials respirator and suit may be required.

· Don't use a broom or vacuum cleaner to clean up dust and dirt. This will only stir up the infected particles.

· Wet down shelves, floors, and other potentially contaminated areas with a liquid disinfectant or a 10% bleach solution.

· Once wet: remove all waste material with a wet towel. Once finished, mop and sponge down the area again with disinfectant.

· If you find any dead rodents or rodent droppings, spray them liberally with disinfectant before removing them.

· Dispose of all cleaning materials in a double bag, and then burn or bury them. If neither of these methods is feasible, contact your state health department for direction.

· Hey, you're still wearing gloves, remember? Disinfect them before taking them off, then wash your hands when finished. Dispose of the gloves, too.

These are merely suggested guidelines. If you are in a rural location and have a structure that is in a poor state of repair, getting rid of all rodents is not feasible, but your ongoing efforts may keep the population down. For more information, contact the Centers for Disease Control and Prevention at 1-800-532-9929 or http://www.cdc.gov/.

Source: These suggestions were written by Marti Stebbins, Fort Lewis College student in SW 340, Archival Theory and Practice, October 16, 2001. She has given the Center her consent to make them available on the Center’s website for the assistance of others. She drew much of this information from the web site of the National Center for Infectious Diseases’ Special Pathogens Branch, “All About Hantavirus,” 2001 June 20.

You are an archivist and have received a box of books from Arizona. When you opened them there are mouse droppings in the box. You become concerned about protecting you and your staff from the Hantavirus that is carried by deer mouse droppings and prevalent in the southwest. What would you do with the box of books?

According to the Office of Special Pathogens, Dr. CJ Peters, Head of the Centers for Disease Control, Atlanta GA. and authors Ali S. Khan and Sally P. Bauer:

Household disinfectants may be used to clean the contaminated area. A commercial disinfectant such as Lysol or a solution of 2-3 tablespoons of bleach per gallon of water may be used. It is a good idea to set down the area since Hantaviruses can be transmitted through the air when dust clouds are created by sweeping and other cleaning activities. Extra precaution should be taken to avoid disturbing any droppings or nesting material. A mask and rubber gloves should be worn when dealing with possible hantaviral contamination and when handling the cleaning products.

As far as cleaning boxes of books containing mouse droppings, a good course of action would be:

1. To make a towel damp with the bleach or Lysol solution and lightly wipe down the box and books.

2. To spray the box and books lightly with a commercial aerosol disinfectant such as Lysol in a spray can. If possible, allow the box and books to be opened and to sit in a well-ventilated area or outdoors. Again, wear a mask and gloves while handling the box and its contents. Scoop up droppings and place them in plastic bags; seal and dispose of the bags.

Source: Ms. Stebbins drew this case study from an actual transmission on the Archives and Archivists list (1995 January 26) from Marcia Watt, Preservation Officer at Emory University Libraries.