Which of the following is NOT recommended to prevent Seoul virus introduction?

• A. Maintain a closed rat colony
• B. Quarantine and test newly acquired rats for Seoul virus
• C. Prevent mixing between pet and wild rats
• D. Mix pet and wild rats

Answer: (D)

Controlling introductions of Seoul virus hinges on biosecurity practices that limit exposure to infected rats and prevent new infections from entering a colony. Keeping a closed rat colony reduces the chance that unknown pathogens slip in; quarantining and testing any newly acquired rats helps ensure they aren’t carrying Seoul virus before they join the main group; and preventing mixing between pet rats and wild rats reduces contact with potential carriers and environmental exposure that could introduce the virus.

Mixing pet and wild rats, on the other hand, increases the risk of exchanging pathogens. Wild rats may harbor Seoul virus even when pet rats appear healthy, and close contact or shared spaces can allow transmission through urine, feces, or aerosols. This defeats the protective steps above and is not recommended.

So the option that should be avoided to prevent Seoul virus introduction is mixing pet and wild rats.