Seoul virus is a type of hantavirus found in many parts of the world, including the United States. It is carried and spread by rodents, specifically the brown or Norway rats, found in the wild, kept as pets, or bred in commercial or home-based facilities (ratteries). Rats can shed the virus and infect people who have contact with urine, droppings, or saliva of infected rodents. People who become infected with this virus often exhibit relatively mild or no disease but some will develop a form of hemorrhagic fever with renal syndrome with death in approximately one to two percent of cases (one to two deaths out of every 100 cases of hemorrhagic fever).

Workers who handle or care for the brown or Norway rat, the known carrier of Seoul virus, should take special precautions to minimize the risk of infection. The CDC recommends that workers follow hantavirus prevention guidance when cleaning up after rodents to reduce the risk of Seoul virus infection. These recommendations include measures for protection of bare skin (i.e., skin that may have cuts or abrasions) and mucous membranes from contact with rodent excreta and nesting materials, hand hygiene, cleaning methods for rodent housing environments and habitats, choice and use of disinfectants, decontamination of equipment, and proper disposal of waste.

Importantly, lung infection with various types of hantaviruses is often associated with respiratory exposure to aerosolized waste materials generated when workers clean and dump soiled bedding from rat cages. Alternative bedding materials that do not generate dusts during replacement and cleaning may help reduce worker exposure to aerosolized material. Especially in large operations, engineering controls, such as ventilated dump stations, can also help protect workers.

In instances where workers must wear personal protective equipment (PPE) to prevent exposure, employers must comply with OSHA’s PPE standards (29 CFR 1910 Subpart I). When working near heavy rodent infestations or around other large populations of rodents, or when conducting tasks that could cause infectious material to become airborne (such as when changing large amounts of bedding or cleaning with high-pressure sprays of water), workers may also need respirators and employers must follow the requirements of the Respiratory Protection standard (29 CFR 1910.134).

The CDC’s Veterinary Guidance for Testing for Seoul Virus in Pet Rats also includes recommendations for diagnostic laboratory testing for rat populations and potentially exposed or infected people.

Resources on this Hantavirus Safety and Health Topics page may also be useful for protecting workers from exposure to Seoul virus in ratteries.