Which statement about mouse hepatitis virus is true?

Which statement about mouse hepatitis virus is true?

• A. It affects the immune system of asymptomatic mice.
• B. It mainly causes diarrhea in adult mice.
• C. It is easily identified because of clear clinical signs.
• D. The only elimination method is embryo rederivation.

Answer: (A)

Mouse hepatitis virus often hides in adult mice, so you can have subclinical infection with real effects on the immune system. The virus can alter immune tissues and responses even when animals look healthy, so the statement that it affects the immune system of asymptomatic mice is true. In practice, clinical signs are not reliable for identifying MHV; diarrhea in adults isn’t a consistent finding and many infected animals appear normal, which is why lab confirmation is needed. Elimination isn’t limited to embryo rederivation—other approaches like depopulation or rederivation with strict testing and barrier practices are also used to eradicate the virus from a colony.

Mouse hepatitis virus often hides in adult mice, so you can have subclinical infection with real effects on the immune system. The virus can alter immune tissues and responses even when animals look healthy, so the statement that it affects the immune system of asymptomatic mice is true. In practice, clinical signs are not reliable for identifying MHV; diarrhea in adults isn’t a consistent finding and many infected animals appear normal, which is why lab confirmation is needed. Elimination isn’t limited to embryo rederivation—other approaches like depopulation or rederivation with strict testing and barrier practices are also used to eradicate the virus from a colony.