ORAL SIV, SHIV, AND HIV TYPE-1 INFECTION

Several strains of simian immunodeficiency virus (SIV), including uncl oned and molecularly cloned SIV strains, can cross intact mucosal surf aces after oral exposure in both adult and neonatal rhesus macaques, r esulting in viremia and disease, Cell-free SIV strains as well as infe cted whole blood have resulted in systemic infection after oral inocul ation. Neonatal macaques, exposed orally to the chimeric SHIV-vpu(+), a derivative of SIVmac239 that encodes the env gene of the T cell-trop ic HIV-IIIB, have also become persistently infected. These data indica te that oral exposure to various virus strains, including T cell-tropi c variants, leads to infection. After nontraumatic inoculation, the or al route was more efficient than the rectal route in permitting SIV en try in adult macaques, Infection and AIDS resulting from oral exposure of adult macaques have implications for the transmission of the human immunodeficiency virus type 1 (HIV-1) during oral-genital contact.