The natural history of human T lymphotropic virus-III infection: the cause of AIDS.

Abstract

This article reviews current knowledge on the etiology modes of transmission immunologic aspects clinical outcome and prevention of acquired immunodeficiency syndrome (AIDS). The isolation of a human retrovirus as the etiologic agent has facilitated clearer understanding of the natural history of AIDS. Antibodies to human T-lymphotropic virus type III (HTLV-III) have been found in over 90% of AIDS patients 80-100% of those with related conditions such as unexplained persistent generalized lymphadenopathy but only 1% of people outside the defined risk groups. 4-7 weeks seems to be the latency period for the development of antibodies in cases of parenteral exposure whereas the amount of time required for seroconversion after sexual transmission is unknown. HTLV-III has been isolated from lymphocytes in peripheral blood bone marrow cells spinal fluid and brain tissue lymph nodes cell free plasma saliva semen and tears. The risk of infection seems to depend most on the route of exposure i.e. blood and blood products sexual contact parenteral drug use and prostitution perinatal transmission. Full blown AIDS is associated with the depression or aberration of most measurable cellular and humoral immune responses. Among those seropositive to HTLV-III but without clinical signs of AIDS the viral interaction with the immune system is not well understood. Even minor reductions in the rate with which HTLV-III is spread will have a large impact on the total number of infected persons a few years from now suggesting the importance of preventive education and counseling. Promiscuity and anonymous sex should be discouraged. Blood organ and sperm donors should be tested for antibodies. Screening should be offered to women in high risk groups who are considering pregnancy and those who are antibody positive should be advised not to become pregnant at least until more knowledge is available.