[Heterosexual transmission of the type I human inmmunodeficiency virus in a group of couples residing in the Yucatán peninsula].

OBJECTIVE

To ascertain the prevalence of type 1 human immunodeficiency virus (HIV-1) and to examine the factors associated with its transmission in a group of heterosexual couples.

DESIGN

Prospective study, descriptive, from September 1985 to December 1989. SITE. A university research center and a private general hospital in the city of Merida, State of Yucatan.

PATIENTS

Twenty-one adult patients (17 men and four women) with initial diagnosis of HIV-1 infection and their respective spouses. All the subjects were residents of the Yucatan peninsula.

INTERVENTIONS

The diagnosis of HIV-1 infection was made by the detection of antibodies against HIV-1 (by ELISA and Western Blot). Both the HIV-1 infection and the stage of AIDS were defined by the CDC criteria. The following factors were evaluated in order to define whether any were associated with the risk of transmission of HIV-1: marital status, time of marital status, type of sexual practices, average number of episodes of sexual intercourse per month, stage of HIV-1 infection of the case, presence of sexually transmitted diseases, and presence of genital ulcers.

RESULTS

Bisexuality was documented in 15 of the 17 males, and in two heterosexual relations with prostitutes was found. The female cases were infected by transfusion (two cases), intravenous drug addiction (one case) and prostitution (one case). Seventeen cases (81%) fulfilled the criteria for AIDS with diagnosis of HIV-1 infection HIV-1 was detected in eight out of 17 female spouses (47%) but not in the four male spouses. No relation was found between the variables and HIV-1 infection.

CONCLUSIONS

The presence of heterosexual transmission of HIV-1 in this study was 38%. The absence of associated factors suggests that heterosexual relations with an infected subject is sufficient for the transmission of HIV-1 to occur. The limited number of female cases makes it difficult to evaluate the efficiency of female-male transmission. Bisexual practices were the predominant cause of HIV-1 infection in the male cases, and as a consequence, the indirect cause of HIV infection in the female spouses.