The seroprevalence of HIV-1 and HIV-2 infections was determined in selected groups of patients from an STD clinic and in female prostitutes from two different states of India. A total of 809 sera from Maharashtra and of 61 sera from Goa were analyzed. Of the unscreened sera from Bombay, 39% were positive as were 15% of the sera from Goa. Among the HIV-positive sera from Bombay, 79% were positive for HIV-1, 4% were positive for HIV-2 and 17% were positive for HIV-1 and 2. In the Goa group, 67% of the infected sera were HIV-1-positive and 33% were HIV-2 positive. Due to the nearly even distribution of infections between men and women, a mainly heterosexual mode of transmission is evident. HIV-2 infections were first detected in India in 1990 (Rübsamen et al., Lancet, 1991). Before that time, Asia was believed to be free HIV-2. The present study represents the first documentation of a large proportion of these infections, alone and in combination with HIV-1, in the Asian continent. An HIV-2 epidemic running parallel to an HIV-1 epidemic so far has never been observed outside of Africa. This would indicate that a further spread of HIV-2 worldwide is to be expected and that HIV-2 should be included in programs of vaccine development for humans.

Because of the great importance of phagocytosis as a key process in host defence, the influence of HIV-infection on the phagocytic activity of monocytes/macrophages (M0/MAC) and granulocytes was investigated. Therefore, blood samples from the peripheral blood of 70 HIV-infected individuals were incubated with fluorescein isothiocyanate (FITC) labeled Escherichia coli. The uptake of the bacteria was monitored by flow cytometer analysis. A strong and significant increase in the relative number of phagocytic granulocytes was observed ranging from 12.8% in an uninfected control collective to over 30% in AIDS patients. This effect was obtained for all patients and independent of the stage of disease. For monocytes, only marginal changes were found in their phagocytic function. These data suggest that the high susceptibility of HIV patients for secondary infections is not linked to a loss of phagocytic ability of monocytes/macrophages and/or granulocytes.

In order to find parameters which allow the assessment of the clinical state of HIV patients with or without antiviral therapy, viral cultures on lymphocytes and monocytes/macrophages, CD4-cell counts, HIV antigen, β2-microglobulin and serum cholesterol were evaluated for their predictive value. As had been shown previously for lymphocytes, the efficiency of viral isolation on macrophages also depends on the disease stage (CDC) of the patients and thus has a high predictive value. A multivariant discriminant analysis showed that the combination of β2-microglobulin, viral antigen, CD4+ cell count and HDL cholesterol predicted the outcome of viral cultures with 80% accuracy. While viral antigen, CD4+ cell counts and β2-microglobulin had been known, HDL cholesterol deserves further evaluation as prognostic parameter. The analysis of HIV derived from patients with AZT showed a 20–200-foldin vitro drug resistance after seven to 24 months of therapy. DNA sequence determination of such strains isolated from AZT patients over time showed only two of the amino acid exchanges described in the literature for resistant strains and an additional Val60-Ile transition after 32 months of therapy.