Which statement best describes Seoul virus infection in rats?

Which statement best describes Seoul virus infection in rats?

• A. Rats frequently show overt illness
• B. Rats never shed the virus
• C. Rats are typically asymptomatic
• D. Transmission to humans requires bites

Answer: (C)

Seoul virus is carried by brown rats and is typically a subclinical infection in those rats. Rats usually do not become ill from the virus, yet they shed it in urine, feces, and saliva, which contaminates the environment and creates exposure risk for people who handle rats or clean areas where rats live. This combination of being a reservoir with little to no illness in the host is why the statement that rats are typically asymptomatic is the best description. Other ideas don’t fit because: rats do shed the virus, so the claim that they never shed is false; transmission to humans mainly occurs through inhalation of aerosolized excreta or direct contact with contaminated materials rather than through bites; and overt illness in rats is not the usual pattern, making the suggestion that rats frequently become ill less accurate.

Seoul virus is carried by brown rats and is typically a subclinical infection in those rats. Rats usually do not become ill from the virus, yet they shed it in urine, feces, and saliva, which contaminates the environment and creates exposure risk for people who handle rats or clean areas where rats live. This combination of being a reservoir with little to no illness in the host is why the statement that rats are typically asymptomatic is the best description.

Other ideas don’t fit because: rats do shed the virus, so the claim that they never shed is false; transmission to humans mainly occurs through inhalation of aerosolized excreta or direct contact with contaminated materials rather than through bites; and overt illness in rats is not the usual pattern, making the suggestion that rats frequently become ill less accurate.