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Biomedical subjects

F I Bastos

Publications and source records attributed to F I Bastos.

32 records · Page 2Linked to original sources
PubMed1999

Perception of vulnerability to HIV infection in a cohort of homosexual/bisexual men in Rio de Janeiro, Brazil. Oswaldo Cruz Foundation STD/HIV Prevention Group.

The present study addresses sociodemographic characteristics, knowledge and attitudes regarding HIV/AIDS, as well as risk behaviour and perception of vulnerability to HIV infection, in the first 295 homosexual and bisexual volunteers (excluding male commercial sex workers and transvestites) taking part in a cohort study in Rio de Janeiro. The sample has a higher socio-economic level than the remainder of the cohort, and than comparable strata of the general population, and a sound knowledge about how to protect themselves against HIV infection. In addition, an association between perception of vulnerability to infection and the practice of unprotected anal sex was observed. An association was also observed between higher levels of formal education and perception of vulnerability; however no association was found with markers for past and recent exposure to sexually transmitted infections (hepatitis B, HbsAG and syphilis). The results of the present study suggest that knowledge and awareness of risk do not easily translate into behaviour change, since significant proportions of the cohort continue to practise unprotected sex with both principal and casual partners, despite their awareness of HIV infection risks as well as preventive measures.

Adolescent↗
PubMed1999

Distribution of HCV genotypes among different exposure categories in Brazil.

Hepatitis C virus (HCV) infection is widespread and responsible for more than 60% of chronic hepatitis cases. HCV presents a genetic variability which has led to viral classification into at least 6 genotypes and a series of subtypes. These variants present characteristic geographical distribution, but their association with different responses to treatment with interferon and severity of disease still remains controversial. The aim of this study was to investigate the patterns of distribution of HCV genotypes among different exposure categories in Brazil. Two hundred and fifty anti-HCV positive samples were submitted to HCV-RNA detection by RT-PCR and their genotype was determined by restriction fragment length polymorphism (RFLP) analysis. In addition, the genotype/subtype of 60 samples was also determined by a reverse hybridization assay. HCV 1 was the most prevalent (72.0%), followed by type 3 (25.3%), HCV 2 (2.0%) and HCV 4 (0.7%). The HCV genotype distribution varied among the different exposure categories, with HCV 1 being more frequent among blood donors, hemophiliacs and hemodialysis patients. A high frequency of HCV 3 was observed in cirrhotic patients, blood donors from the South of Brazil and injecting drug users (IDUs). The general distribution of the HCV genotype in Brazil is similar to that in other regions of the world.

Blood Donors↗
PubMed1999

Prevalence and risk factors for HBV, HCV and HDV infections among injecting drug users from Rio de Janeiro, Brazil.

Viral hepatitis constitutes a major health issue, with high prevalence among injecting drug users (IDUs). The present study assessed the prevalence and risk determinants for hepatitis B, C and D viruses (HBV, HCV and HDV) infections among 102 IDUs from Rio de Janeiro, Brazil. Serological markers and HCV-RNA were detected by enzyme immunoassay and nested PCR, respectively. HCV genotyping was determined by restriction fragment length polymorphism analysis (RFLP). HBsAg, anti-HBc and anti-HBs were found in 7.8, 55.8 and 24. 7% of IDUs, respectively. In the final logistic regression, HBV infection was independently associated with male homosexual intercourse within the last 5 years (odds ratio (OR) 3.1; 95% confidence interval (CI) 1.1-8.8). No subject presented anti-delta (anti-HD). Anti-HCV was detected in 69.6% of subjects, and was found to be independently associated with needle sharing in the last 6 months (OR 3.4; 95% CI 1.3-9.2) and with longer duration of iv drug use (OR 3.1; 95% CI 1.1-8.7). These data demonstrate that this population is at high risk for both HBV and HCV infection. Among IDUs from Rio de Janeiro, unprotected sexual intercourse seems to be more closely associated with HBV infection, whereas HCV is positively correlated with high risk injecting behavior. Comprehensive public health interventions targeting this population and their sexual partners must be encouraged.

Adult↗
PubMed1999

Income inequality and homicide rates in Rio de Janeiro, Brazil.

OBJECTIVES: This study determined the effect of income inequality on homicide rates in the state of Rio de Janeiro, Brazil. METHODS: We conducted an ecological study at 2 geographical levels, municipalities in the state of Rio de Janeiro and administrative regions in the municipality of Rio de Janeiro. The association between homicide and income inequality was tested by multiple regression procedures, with adjustment for other socioeconomic indicators. RESULTS: For the municipalities of Rio de Janeiro State, no association between homicide and income concentration was found an outcome that can be explained by the municipalities' different degrees of urbanization. However, for the administrative regions in the city of Rio de Janeiro, the 2 income inequality indicators were strongly correlated with the outcome variable (P < .01). Higher homicide rates were found precisely in the sector of the city that has the greatest concentration of slum residents and the highest degree of income inequality. CONCLUSIONS: The findings suggest that social policies specifically aimed at low-income urban youth, particularly programs to reduce the harmful effects of relative deprivation, may have an important impact on the homicide rate.

Adolescent↗
PubMed1998

Molecular epidemiology of HIV-1 in Brazil: high prevalence of HIV-1 subtype B and identification of an HIV-1 subtype D infection in the city of Rio de Janeiro, Brazil. Evandro Chagas Hospital AIDS Clinical Research Group.

HIV-1-positive individuals were recruited from January 1993 to December 1996 from several cohorts receiving follow-up in the city of Rio de Janeiro, Brazil, to evaluate HIV-1 genetic variability and the potential association with modes of transmission. HIV-1 subtyping was carried out using the heteroduplex mobility assay (HMA), and those samples corresponding to the typical Brazilian subtype B variant were further identified based on the Fok I restriction fragment length polymorphism (RFLP). DNA sequencing was performed to evaluate one case of subtype D infection. From the 131 HIV-1-positive individuals analyzed, 106 (80.9%) could be identified as infected by subtype B and 20 (15.3%) by subtype F. One of the samples (0.8%) was classified as subtype D. DNA samples from 4 patients (3.0%) did not yield polymerase chain reaction (PCR)-amplified products to be typed. Based on the Fok I RFLP, 39 of the 106 subtype B samples (37%) were identified as corresponding to the typical Brazilian subtype B variant containing the GWGR motif at the tip of the V3 loop. No statistically significant association could be detected between HIV-I subtypes and modes of transmission, exposure categories, or gender. This is the first reported case of HIV-1 subtype D infection in Brazil.

Amino Acid Sequence↗
PubMed1997

Risk behavior and HIV seroprevalence among injecting drug users in Rio de Janeiro, Brazil.

OBJECTIVE: To characterize HIV seroprevalence and risk behavior among injecting drug users (IDUs) in Rio de Janeiro, Brazil, between 1990 and 1996. DESIGN: We report data from three separate cross-sectional samples of IDUs in Rio de Janeiro: the World Health Organization (WHO) sample (n = 479), the Proviva sample (n = 138) and the Brasil sample (n = 110). These data provide the most comprehensive view available, to date, of this understudied population in Rio. METHODS: Demographic characteristics, HIV/AIDS risk behavior and HIV seroprevalence were compared across the three samples and combined analyses were performed to determine the factors associated with injecting risk behavior, sexual risk behavior and HIV seropositivity. RESULTS: The overall HIV seroprevalence among IDUs was 25%. Two encouraging findings of the present analysis were the lower levels of needle-sharing among participants recruited in the latest years (1995-1996) and the lower HIV seroprevalence in the Proviva sample composed mainly of less educated, poorer IDUs living in deprived neighborhoods. No trends toward safer behavior were found for sexual risk, younger age being the principal factor associated with high risk. CONCLUSIONS: Levels of needle-sharing and sexual risk among IDUs in Rio remain high, demonstrating the urgent need to increase the limited preventive measures undertaken so far. Seroprevalence levels for HIV remain significantly lower in the most deprived sample, arguing for the fundamental importance of prompt and effective prevention strategies to keep infection rates from rising among the poorest and largest strata of Rio's IDUs.

Adolescent↗
PubMed1996

[Social networks and diffusion of AIDS in Brazil].

The HIV/AIDS epidemic has been simplistically interpreted as a phenomenon restricted to risk groups that are socially and spatially circumscribed. However, epidemic trends in recent years have demonstrated the need to employ open diffusion models that emphasize social interaction as a means of spread of HIV. This study is a spatial analysis of the AIDS epidemic in Brazil, which sought to incorporate variables reflecting economic and demographic events into a system for processing geographically referenced health information. Findings indicate that metropolises and regional urban centers, mainly those in the Southeast, play an important role in the spread of the epidemic, not only because of their population density but also because they are centers of trade and social interaction. In smaller cities located in the state of São Paulo, a large number of AIDS cases among injecting drug users are concentrated, revealing the routes and centers of cocaine use.

Acquired Immunodeficiency Syndrome↗
PubMed1995

[The social geography of AIDS in Brazil].

The first of a series of papers concerning the evaluation of the dynamics of the AIDS epidemic in Brazil employing techniques of geographical analysis, is here presented. Results of research undertaken in the US (especially in New York City) are compared with those of a recent investigation carried out in the city of S.Paulo, Brazil (Grangeiro, 1994). In both, geographical patterns of socio-demographic variables correlate with different patterns of the spread of the AIDS epidemic through the transmission groups. Recent trends of the AIDS epidemic in Brazil: the displacement toward medium sized cities and expansion frontiers, increasing report of AIDS cases among the poor and underprivileged, changes in the pattern of transmission with proportional augmentation of heterosexual transmission and IDUs as transmission groups, are described and analysed. The geographical distribution of the AIDS cases registered between 1987-1993 in Brazil throughout the Brazilian States is evaluated by means of worksheets, maps, and non-parametric statistics. Results show that Gravimetric Centers (obtained by the use of the calculus spatial means) of AIDS in Brazil are situated within a triangle the sides of which are formed lines joining the three main metropolitan areas of the wealthiest region of Brazil--the southeast, i.e. São Paulo, Rio de Janeiro and Belo Horizonte. These especially S. Paulo, function as points of attraction for these Gravimetric Centers (GCs) towards the south as compared with the GCs of the general population calculated ia accordance with data from the 1980 and 1991 censuses. It is possible to observe a displacement of the GCs toward the northwest over this period in accordance with the migration patterns of the Brazilian population in general, though with a dynamic of its own. These changes in the geographical, socio-demographic and transmission group patterns show the complex nature of the epidemic in Brazil and pose additional difficulties for the development of prevention strategies.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Risk factors for HIV-1 seroprevalence among drug injectors in the cocaine-using environment of Rio de Janeiro.

To determine risk factors for HIV-1 among drug injectors in Rio de Janeiro, where cocaine is the dominant drug of injection, subjects were recruited using the criteria and interview instrument of the World Health Organization's Cross-National Study of HIV infection and risk behaviour in injecting drug users. HIV antibody test results were derived both from serum tests and from self-reports of previous tests (documented evidence of self-reported seropositivity was required). The analytical sample consists of 123 subjects, recruited both at drug abuse treatment sites and at street locations. Of 27 subjects with both serological and self-reported antibody status data, 20 reported previous negative tests; of these three had positive sera and may have seroconverted. Seven subjects reporting prior positive serostatus all tested positive. For the 123 subjects, seroprevalence was 34%. Independent significant risk factors in multivariate logistic regression with backwards elimination are: years of injection greater than 5; being a male who has had sex with men in the previous 5 years; and not having taken deliberate steps to protect oneself against AIDS. These findings indicate that homosexual/bisexual male drug injectors may be a bridge group through which HIV is entering drug-injecting networks in Rio de Janeiro. Efforts by drug injectors to reduce their risk of infection seem to have protective effects. This underscores the importance of HIV prevention efforts aimed at drug injectors.

Brazil↗
PubMed1993

HIV infection and AIDS among drug injectors at Rio de Janeiro: perspectives and unanswered questions.

Data from various countries show considerable variation in the rate of spread of the human immunodeficiency virus (HIV) among drug injectors. Although further research is needed to predict the rate of increase of seroprevalence at Rio de Janeiro, preliminary data confirm the presence of the virus, with a seroprevalence of about 33 per cent in 1990. Issues arising from research into the probable determinants of viral spread among the thousands of drug injectors in the city are outlined in the present paper. Even before the research is completed, however, it is clear that interventions are needed to reduce further viral transmission both among drug injectors and from them to their sexual partners and offspring. Efforts should be made to prevent the population at risk from initiating the practice of drug injection, and to promote a major expansion in drug abuse treatment facilities. Drug injectors should also be encouraged to reduce the risk of their becoming infected or passing on the virus to others, through educational outreach, through the distribution of supplies that facilitate risk reduction (bleach, syringes, condoms), and through innovative approaches to behaviour change.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

HIV specific humoral immune response in Rio de Janeiro, Brazil. The HEC/Fiocruz AIDS Clinical Research Group.

Efforts to characterize HIV-1 polymorphism and anti-HIV immune response are being made in areas where anti-HIV/AIDS vaccines are to be employed. Anti-HIV-1 humoral immune response is being studied in infected individuals residents in Rio de Janeiro, in distinct cohorts involving recent seroconvertors, pregnant women or intravenous drug users (IDU). Comparative analyses of specificity of antibody response towards epitopes important for anti-HIV-1 immune response indicate quantitative differences between cohorts, with an exceptionally strong response in IDUs and weakest response in pregnant women. However, a comparative analysis between pregnant women cohorts from Rio de Janeiro and Rio Grande do Sul indicated an even lower response (with exception of the anti-V3-C clade peptide recognition) for the southern cohort. Studies analysing the immune function of the humoral response indicate a quite elevated occurrence of antibodies capable for neutralizing heterologous primary HIV-1 isolates from Rio de Janeiro. Attempts to correlate seroreactivity with HIV-1 neutralization with respect to HIV-1 polymorphism were not very successful: while the Brazilian B clade B " variant could be recognized by binding assays, no significant distinction of HIV-1 clades/variants was observed in viral neutralization assays.

Antibody Formation↗
PubMedDate not supplied

[Income inequality and health: the case of Rio de Janeiro].

This ecological analysis addresses the association between income inequality and health status in the municipality of Rio de Janeiro. Data were analyzed using geo-processing and multiple regression techniques. The following health indicators were used: infant mortality rate; standardized mortality rate; life expectancy at birth; and homicide rate among 15-29-year-old males. Patterns of income inequality were assessed through income distribution indicators: Gini index, Robin Hood index, and top 10 %/bottom 40% average income ratio. The results indicate significant correlations between income distribution indicators and health indicators, providing additional empirical evidence of the association between health status and income inequality. For the homicide rate, the effect of the indicator "density of slum residents" was also relevant, suggesting that further deterioration in health standards may be due to social disruption of deprived communities and the resultant increase in criminal activity. The geo-epidemiological analysis presented here highlights the association between adverse health outcomes and residential concentration of poverty. Social policies focused on slum residents are needed to reduce the harmful effects of relative deprivation.

Adolescent↗
PubMedDate not supplied

[AIDS epidemic dynamics in the municipality of Rio de Janeiro, Brazil, 1988-1996: Spatial-temporal statistic modeling].

This study uses a spatial-temporal model to analyze the spatial spread of the AIDS epidemic (adult cases) in the municipality of Rio de Janeiro, Brazil, during three periods: 1988-1990, 1991-1993, and 1994-1996. City districts were used as the geographic units of analysis. A spatial analysis was also performed for pediatric AIDS cases due to vertical HIV transmission, according to period of birth, 1985-90 and 1991-96. For total adult AIDS cases, the initial period was characterized by a polygonal cluster located around the harbor area, which expanded from west to east. Among homosexual cases, in situ growth predominated, and a decrease in the intensity of the diffusion process was observed from the second to the final period. Among heterosexual cases, the epidemic displayed a relevant geographic spread, mainly from 1988-1990 to 1991-1993. Among female cases in the final time period, a cluster of high incidence rates was found towards the northwest, including very poor areas. Among pediatric cases in 1991-1996, a significant correlation was found between AIDS incidence rates and poverty levels in the respective municipal districts. The results suggest that a more complete understanding of AIDS spatial-temporal dynamics can make a major contribution to preventive measures.

Acquired Immunodeficiency Syndrome↗