FACTORS INFLUENCING THE PERSISTENCE OF CHORIOMENINGITIS VIRUS IN THE BLOOD OF MICE AFTER CLINICAL RECOVERY

Abstract

Mice infected in utero continued to carry choriomeningitis virus in the blood more regularly and in greater amount than suckling mice infected by contact. This result may be due to the difference in tissue maturity at the time of infection: the more immature the tissues are when infected, the longer the virus appears to persist in them after maturation. A similar result was obtained with mice of different ages infected either by contact or by intranasal instillation of virus, in that the carrier state lasted longer in the younger animals. This cannot be attributed entirely to the difference in age, however, since young mice as a rule showed more severe symptoms than mature animals. It is possible, therefore, that the difference in the severity of the disease accounted in part for that in the duration of the infection.