Recommendation for prevention of Seoul virus

Recommendation on how to minimize the risk of Seoul virus infection.

Persons handling rodents such as the brown or Norway rat, which are known reservoir species of Seoul virus, a species of hantavirus, should take special precautions to minimize risk of infection. Special consideration should be given to protection of broken skin and mucous membranes from contact with rodent feces, urine and saliva; and also, special consideration should be given to hand hygiene, choice and use of disinfectants, decontamination of Seoul virus infection.

These recommendations will be revised and updated as additional information becomes available.

Cleaning up after rodents 

It is recommended to take precautions before, during, and after a rodent interaction, or when cleaning a rodent-infested or housing environment.

1. Before starting to clean, ventilate the space by opening doors and windows for at least 30 minutes for fresh air to enter the area. Use cross-ventilation whenever possible and leave the area during the airing-out period.

2. Clean up any urine and feces

   • When you begin cleaning, do not stir up dust by sweeping or vacuuming up feces, urine, or nesting materials.
   • Wear rubber, latex, or vinyl gloves when cleaning urine, feces.
   • Spray the urine and feces with a disinfectant or a mixture of bleach and water and let soak 5 minutes. The recommended concentration of bleach solution is 1 part bleach to 10 parts water. When using a commercial disinfectant, follow the manufacturer's instructions on the label for dilution and disinfection time. More information on appropriate disinfectants is below (#4).
     
   • Use a paper towel to pick up the urine and feces, and dispose of the waste in the garbage. After the rodent feces and urine have been removed, disinfect items that might have been contaminated by rodents or their urine and feces.
     

3. Bedding materials: special consideration should be given when cleaning bedding materials and nests of rodents suspected to be infected with Seoul virus.

   • Wet the materials throughout with disinfectant right after the rodent is removed from the cage and before anything else is done. The disinfectant should be allowed to sit on the bedding for approximately 10 minutes.
   • Dispose of soaked material in a plastic bag. Gently close the bag at the top and seal shut with tape. Avoid squeezing or pressing the bag to get excess air out. Then place this bag in second, empty plastic bag. Again, gently tape the bag shut.
   • If the bedding is not disinfected properly, it presents a danger to anyone who happens to come into contact with that closed trash bag (i.e.: sanitation workers).
   • Personal protective equipment is recommended. Please see section below.
     

4. Disinfect additional areas where the rodent was housed to inactivate any virus remaining in the environment.

   • Spray down or wipe rodent enclosures (i.e.: cages or tubs) with disinfectant and allow to sit for 5 minutes.
   • Spray or mop the floor with disinfectant so that it is thoroughly wetted down. This includes carpeted floors. After 5 minutes, use of a respirator is no longer required. Steam clean or vacuum can then be used after application of disinfectant.
   • Wipe or spray walls, furniture, or cabinets with disinfectant.
     

5. Persons involved in the clean-up of heavy rodent infestations or habitats should wear the protective equipment listed here:

   • Coveralls (disposable, if possible);
   • Two pairs of non-powdered nitrile medical-grade gloves plus a thick protective glove (i.e., bite/scratch resistant). Protective gloves may be made of leather or of fabric with a rubber outer coating that is thick and resistant to puncture from rodent bites or scratches and is easy to disinfect.
   • A disposable face shield to protect mucous membranes from any accidental splashes of rodent urine or blood
   • A NIOSH-certified N95 filtering face piece respirator or higher or a powered air purifying respirator (PAPR) equipped with a high-efficiency particulate ar filter (HEPA). 
     • Workers must be fit tested to ensure that facial hair will not interfere with the safe use of an N95 or other tight-fitting respirators. Tight-fitting respirators cannot be used by people with facial hair that comes between the sealing surface of the face-piece and the face; loose-fitting powered air purifying respirators (PAPRs) can be worn by those with facial hair.
   • Personal protective gear should be decontaminated upon removal at the end of the day. All potentially infective waste material (including respirator filters) from clean-up operations that cannot be burned or deep-buried on site should be double-bagged in appropriate plastic bags. The bagged material should then be labeled as infectious (if it is to be transported) and disposed of in accordance with local requirements for infectious waste.
     

6. Disinfectants

   • Hantaviruses like Seoul virus are sensitive to dilute hypochlorite solutions (10% household bleach), 5% hospital-grade Lysol, phenolics, detergents, and most general-purpose household disinfectants.
   • A 1% (1:100 dilution) solution of household bleach is an adequate surface disinfectant which can be used for wiping down potentially contaminated surfaces. For heavily soiled areas or items contaminated with rodent feces or nesting items, a 10% solution is more effective.
   • An appropriate disinfectant should always be used:
     • To decontaminate traps which contained or were soiled by rodents
     • To clean rubber gloves after handling traps which contain rodents or that have been soiled by rodents
     • To clean gloved hands after each rodent is handled and before removing gloves
     • To soak and disinfect instruments and other equipment
     • To clean working surfaces and other items that may have been contaminated by handling rodents