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To determine whether human T cell lymphotropic virus type 1 (HTLV-1) infection is associated with delayed neurological development, we examined 48 Peruvian children with exposure to HTLV-1 who were identified at the Instituto Materno-Perinatal. Compared with 38 HTLV-1-seronegative children, the 10 seropositive children did not have higher rates of neurodevelopmental delay. Long-term follow-up is planned.

Seropositivity to the AIDS-associated retrovirus, HTLV-III/LAV, has profound implications. Simple and reliable tests are needed to detect such antibodies. A rapid, sensitive indirect immunofluorescence assay (IFA) on acetone-fixed virus-producing CEM/LAV-N1 cells was adapted for detection of human antibodies to HTLV-III/LAV. Specific and nonspecific patterns of of immunofluorescent reactivity were easily distinguished, and results paralleled those obtained by Western blotting and radioimmunoprecipitation (RIP), indicating that there is no need to confirm IFA positivity. In contrast, the commercial enzyme-linked immunosorbent assay (ELISA) was less reliable. False positives occurred with sera from seven hemophiliacs that were negative on Western blots, and false-negative reactions were observed on two occasions. These involved low-titer AIDS-patients' sera that were positive on Western blots, and from one of which virus was successfully isolated. Our results emphasize the requirement for confirmatory assays when the ELISA test is used for primary screening of sera for antibodies to HTLV-III/LAV. The IFA method is especially well-suited to quantitative analysis of serum antibody levels. Our data suggest that serum antibody titers rise as disease progression occurs, ultimately falling as severe complications ensue. It is suggested that in laboratories where the demand for HTLV-III/LAV antibody testing is not excessive (1,000-2,000 sera/month), IFA could serve as the only serological assay for both screening and epidemiological purposes.

Serum samples from 850 individuals from Venezuela were tested for the presence of antibodies to HTLV-III/LAV virus, the probable etiological agent of acquired immune deficiency syndrome (AIDS). At the time of the study, none of the individuals tested had symptoms indicative of AIDS or related disorders. Viral antibodies were assayed by indirect immunofluorescence (IF) assay, using a chronically infected, HTLV-III/LAV producer cell line CEM/LAV-NIT established in our laboratory. Twenty individuals (2.5%), 8 of them (40%) female, were seropositive by IF and by confirmatory Western blotting and radioimmunoprecipitation assays. The seropositivity rate ranged from 2.4% (11 of 465) in the general healthy population, 4% (2 of 50) among patients with Chagas' disease, and up to 29.2% (7 of 24) among patients with acute malaria infection. The titers of HTLV-III/LAV antibodies ranged from 1:40 to 1:640. In addition, 2 of 36 patients with hemophilia A (5.5%) also had antibodies to HTLV-III/LAV. Two of 7 patients with acute malaria had specific antibodies both to HTLV-III/LAV and HTLV-I, as determined by IF and Western blotting. None of over 169 randomly chosen, healthy blood donors from seven major Venezuelan cities, as well as none of 99 patients with leukemia/lymphoma, had antibodies to HTLV-III/LAV. The presence of specific antibodies among various Venezuelan populations indicates that HTLV-III/LAV, or a closely related cross-reactive virus, is indigenous in Latin American subjects as was previously indicated for tropical populations of central Africa. Isolation and characterization of this virus will help to understand the origin and etiology of AIDS.

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