Cytomegalovirus infection in weanling guinea pigs.

Cytomegalovirus (CMV) infection of weanling guinea pigs was studied after subcutaneous and intracerebral inoculation of virus. No clinical illness appeared by day 24 after subcutaneous inoculation, even though animals developed persisting infection in many tissues, with marked variation in histogogic expression. Virus was obtained in higher titer from homogenates of salivary gland and thymus tissue. In other organs, including the brain, virus was found only be cocultivation of trypsinized liver tissue cells with guinea pig embryo cells. Appearance of virus in tissue culture was sometimes delayed for more than a month. After intracerebral inoculation, multifocal inclusion cell encephalitis developed, with spread of virus to other organs. Histologically this condition resembled findings in renal transplant patients with CMV infection. The study of CMV infection in guinea pigs may yield information applicable to human CMV infection.