Evidence for Exposure to HTLV-III in Uganda Before 1973

Abstract

Fifty of 75 serum samples collected in the West Nile district of Uganda between August 1972 and July 1973 contained antibodies reactive with human T-cell leukemia (lymphotropic) virus type 3 (HTLV-III; mean titer, 601), while 12 of 75 samples were positive in a similar test for HTLV type 1 (HTLV-1) antibodies (mean titer, 236). The samples were screened by enzyme-linked immunosorbent assay and positive results were confirmed by a newly developed unlabeled antibody-peroxidase procedure with enhanced sensitivity for detection of antibody binding to immunoblots of HTLV-III antigen, demonstrating antibodies to proteins with molecular weights of 24,000, 41,000, and 76,000 in nearly all positive samples. Analysis of titration data indicated enhanced titers of antibody against HTLV-III and HTLV-I when coinfection occurred. The high prevalence and relatively low titers [compared to serum from patients with acquired immune deficiency syndrome (AIDS)] of antibodies recognizing HTLV-III proteins in sera from this population at a time that may predate or coincide with the appearance or spread of the AIDS agent (HTLV-III) suggest that the virus detected may have been a predecessor of HTLV-III or is HTLV-III itself but existing in a population acclimated to its presence. It further suggests an African origin of HTLV-III.

Absence of antibodies to the human immunodeficiency virus in sera from Africa prior to 1975.

“…§1734 solely to indicate this fact. (8) that have been questioned (18,20). The reason for the discrepancy between the earlier and our studies may be a cross-reactivity of some African sera with contaminating cellular antigens in the assay system, nonspecific stickiness of the sera to proteins, or antibodies against a distantly related virus (8,18,20).…”

“…An incidence of close to 60%o was reported (8) (9). These children ranged in age from 4 to 12 yr and had no signs of disease.…”

The Epidemiology of AIDS: Current Status and Future Prospects

“…HTLV-IIL/LAV antibody was reported to have been found in 50 of 75 serum samples collected from healthy children in Uganda as early as 1972 and 1973 (15). Since AIDS has not been reported from Uganda, the interpretation of this finding is unclear.…”

The uniqueness of HIV infection

“…To date, where the virus came from is still unclear. At this time, the most plausible explanation is that HIV originated in Africa [20]. Viruses similar to HIV have been found in Old World monkeys, such as the macaques.…”