[Mouse hepatitis virus]

Mouse hepatitis virus (MHV), the coronavirus of the mouse (mus musculus), is one of the most important viral pathogens in contemporary laboratory mouse colonies. It is a highly mutable virus consisting of numerous antigenically distinct serotypes with different pathology. These can be divided according to their tissue tropism into respiratory and enterotropic strains. The course of an MHV infection is dependent on virus strain and host factors. Generally MHV causes an acute, self limiting infection which is inapparent in adult mice. Neonates are highly susceptible to disease and show high mortality. In an enzootically infected colony however, they are protected by maternally derived passive immunity. MHV's importance in biomedical research on one hand stems from its potential as an interfering agent, mainly in the field of immunology. On the other hand MHV serves as a model for coronaviruses of other species including man in studies on virus replication and tissue tropism. Since MHV infections are usually subclinical, detection depends on serological screening of colonies using Enzyme-linked immunosorbent assay (ELISA) or immunofluorescence. MHV is controlled by culling and rederivation of the affected colony using hysterectomy or embryo transfer or by elimination by cessation of breeding.