Hepatitis, necrotizing, acute, random, multifocal, moderate, with syncytia, nude mouse, rodent. The causative agents are coronaviruses that are also referred to as murine hepatitis virus, murine hepatoencephalitis virus and the lethal intestinal virus of infant mice. MHV is common in commercial and research mouse colonies and is highly contagious. Respiratory, fecal-oral and vertical transmission occur. The type and severity of disease produced is determined by the viral strain and host factors such as strain, age, route of inoculation and concurrent infection with other agents.
Most infections are subclinical.
Generally, disease expression requires immature, immunocompromised or genetically susceptible mice. Depending on the viral strain, two patterns of disease occur. Strains with a respiratory tropism infect the upper respiratory tract and may disseminate causing hepatitis and encephalitis in susceptible hosts. Enterotropic strains can infect the entire length of the intestinal tract, but the cecum, ascending colon and distal small intestine are preferred sites. Necrotizing lesions with syncytia may occur in the liver, brain, intestine, spleen and lymph nodes.