HIV-1 seroprevalence in the general population of Salvador, Bahia State, Northeast Brazil.

To estimate HIV-1 seroprevalence in the general population of Salvador, Bahia, Brazil, we conducted a cross-sectional survey of 3,437 residents from 1998 to 2000. Subjects were drawn from 30 sentinel areas representing a wide range of living conditions. Plasma samples were screened for HIV-1 antibodies by ELISA and confirmed by immunofluorescent assay. Subtype determination by HMA was performed after proviral DNA amplification. Phylogenetic analysis using parsimony was performed with the neighbor-joining method. Overall HIV-1 seroprevalence was 0.55% (19/3,446): 0.8% for men and 0.36% for women. Seroprevalence was higher in the 31-45-year age group (1%) and among persons with family income less than twice the minimum wage (0.78%) as compared to 0.33% for the higher income group. Syphilis was detected in 37% of HIV seropositive individuals. Phylogenetic inferences identified 10 samples as subtype B in the env region and 2 samples with Benv/Fgag/Fpol and Fenv/Bgag. Age > or = 30 years, male gender, and income < or = 2 times the minimum wage were identified as risk factors for HIV-1 infection. Extrapolating the proportion of seropositive individuals to Salvador, the number of HIV-1 infected individuals was estimated at 13,750.

Inhibition of HIV-1 infection by monoclonal antibodies to carbohydrates of Schistosoma mansoni.

Patients infected with HIV-1 develop a potent humoral immune response against the virus, but HIV-1 primary isolates are remarkably resistant to neutralizing antibodies. Considering that the envelope glycoprotein of HIV-1 (gp120/41) is heavily glycosylated, we investigated whether anti-carbohydrate antibodies could inhibit HIV-1 infection in vitro. We studied the neutralizing activity of three monoclonal antibodies (mAbs) raised to carbohydrates of Schistosoma mansoni, against seven primary isolates of HIV-1. Assays were performed infecting peripheral blood mononuclear cells from normal donors with viral isolates previously treated with mAbs. Viral strains used were tropic for the coreceptors CCR5, CXCR4, and dual-tropic ones. We found that the anti-glycan mAbs vigorously inhibited HIV-1 infection, regardless of the preferential coreceptor usage of the isolate, in a dose-response manner. Importantly, five isolates were resistant to neutralization by two HIV-1 antibody-positive human sera endowed with potent anti-HIV-1 inhibitory activity. Our findings suggest that carbohydrates of the HIV-1 viral envelope may be a target of an effective humoral immune response elicited by vaccination.

HIV-1 seroprevalence in the general population of Salvador, Bahia State, Northeast Brazil / Soroprevalência do HIV-1 na população geral de Salvador, Bahia, Brasil

To estimate HIV-1 seroprevalence in the general population of Salvador, Bahia, Brazil, we conducted a cross-sectional survey of 3,437 residents from 1998 to 2000. Subjects were drawn from 30 sentinel areas representing a wide range of living conditions. Plasma samples were screened for HIV-1 antibodies by ELISA and confirmed by immunofluorescent assay. Subtype determination by HMA was performed after proviral DNA amplification. Phylogenetic analysis using parsimony was performed with the neighbor-joining method. Overall HIV-1 seroprevalence was 0.55 percent (19/3,446): 0.8 percent for men and 0.36 percent for women. Seroprevalence was higher in the 31-45-year age group (1 percent) and among persons with family income less than twice the minimum wage (0.78 percent) as compared to 0.33 percent for the higher income group. Syphilis was detected in 37 percent of HIV seropositive individuals. Phylogenetic inferences identified 10 samples as subtype B in the env region and 2 samples with Benv/Fgag/Fpol and Fenv/Bgag. Age > 30 years, male gender, and income < 2 times the minimum wage were identified as risk factors for HIV-1 infection. Extrapolating the proportion of seropositive individuals to Salvador, the number of HIV-1 infected individuals was estimated at 13,750.

A seroprevalência do HIV-1 na população geral de Salvador, Bahia, Brasil, foi estimada em estudo de corte transversal com 3.437 indivíduos entre 1998-2000, residentes de 30 áreas sentinelas com ampla va-riedade de condições de vida. Realizou-se uma triagem para anticorpos anti-HIV-1 por ELISA e confirmados por imunofluorescência. A determinação do subtipo foi realizada por HMA, após amplificação do DNA proviral. As análises filogenéticas foram realizadas com PAUP utilizando os algoritmos neighbor-joining. A seroprevalência do HIV-1 foi de 0,55 por cento (19/3.446): 0,8 por cento para os homens e 0,36 por cento para as mulheres. A seroprevalência foi mais alta no grupo de 31-45 anos (1 por cento) e entre as pessoas com renda familiar inferior a dois salários mínimos (0,78 por cento). A sífilis foi diagnosticada em 37 por cento dos participantes HIV soropositivos. A análise filogenética identificou 10 amostras como subtipo B na região env, e duas amostras Benv/Fgag/Fpol e Fenv/Bgag. Idade > 30 anos, sexo masculino, renda < 2 salários mínimos se comportaram como fatores de riscos para a infecção por HIV-1. Se extrapolarmos a proporção de soropositivos para Salvador, o número de infectados pelo HIV seria 13.750.