Prevalence of HIV-1, HIV-2 and HTLV antibody, in Fortaleza, Ceara, Brazil, 1993-1994.

To evaluate the respective part of HIV-1, HIV-2, and human T lymphotropic virus (HTLV) infection in Fortaleza, the principal city of the Ceara state (Northeast of Brazil), a cross-sectional seroepidemiological survey was conducted from July 1993 to February 1994 in 6 selected groups: pregnant women, tuberculosis (Tb) patients, sexually transmitted disease (STD) patients, female and male commercial sex workers (CSWs) and prisoners. Sera were screened by Mixt HIV-1/HIV-2 commercial enzyme immunoassay and ELISA HTLV I/II. Each serum found positive by ELISA was confirmed by Western blot. A total of 2917 persons were interviewed, of whom 2754 (94.4%) agreed to participate and gave a blood sample. Twenty-eight were found to be HIV-1 antibody positive. The prevalence ranged from 0.25% in pregnant women to 2.9% in male CSWs. The prevalence was 1% in STD patients and 0.44% in Tb patients. None of the sera was found positive for HIV-2. The prevalence of antibodies to HTLV-1 varied from 0.12% in pregnant women to 1.21% in female CSWs. Five sera were positive for HTLV-II. These results confirm the hypothesis that the HIV epidemic in Northeastern Brazil is still limited to high risk groups. Repeated cross-sectional surveys of this type should be performed as a surveillance tool to study the dynamics of this epidemic in low prevalence areas. Defining risk factors should allow targeting of intervention strategies.