SEXUAL TRANSMISSION OF SIMIAN T-LYMPHOTROPIC VIRUS TYPE-I - A MODEL OF HUMAN T-LYMPHOTROPIC VIRUS TYPE-I INFECTION

Simian T-lymphotropic virus type-I (STLV-I) seronegative females placed together with seropositive melee for breeding purposes were followed from 1984-1990 to determined seroconversion rates by enzyme immunoassay and western immunoblot analysis. Two of 26 females end 1 of 4 males previously negative for antibodies to STLV-I seroconverted during the study period. Statistical analysis of sexual encounters indicated that the probability of a seronegative female testing positive for STLV-I after a sexual encounter with a seropositive male is leer than 4%. These data indicate that even though sexual contact is important in the transmission of STLV-I. it may not be an efficient mode of viral infection. These data also suggest that female-to-male transmission of STLV-I occurs. as recently reported for human T-lymphotropic virus type-I (HTLV-I) infection. These results are important because HTLV-I and STLV-I share many features in common including routes of viral transmission. In addition. the difficulty of clearly quantitating the risks of sexual transmission in humans makes the primate animal model a valuable alternative to study the human infection.