Adult infections are again usually asymptomatic. As the infection becomes established in the colony, the epizootic pattern is replaced with the enzootic pattern. Numerous reports document effects of natural or experimental infection with MHV on host physiology and research. Clearly, natural MHV infection of laboratory mice with MHV may affect a plethora of scientific studies and seriously compromise the value of these animals as research subjects. SDAV is an ssRNA virus of the family Coronaviridae.
Transmission is via direct contact and fomites.
Infant mice, but not adult immunocompetent or scid mice, are susceptible to experimental infection. Natural infection of mice has not been reported. SDAV infections follow patterns similar to those of MHV, another coronavirus. Suckling rats develop transient conjunctivitis. Weanlings and adults are asymptomatic.