A potential syndemic effect associated with symptoms of depression among men who have sex with men

INTRODUCTION

Globally, depression rates are high among men who have sex with men (MSM). Multiple factors may interact synergistically to increase this risk. This analysis assessed the prevalence of symptoms of depression among MSM in Brazil and synergistic effects of several factors.

METHODS

Cross-sectional study conducted in 12 cities using respondent-driven sampling. Sociodemographic and behavioral characteristics were collected. The PHQ-9 was used to screen for depression. Having moderate-severe depressive symptoms was compared to none-mild using logistic regression. The syndemic factor was a composite of hazardous alcohol use, sexual violence, and discrimination due to sexual orientation. Those with one to three of these factors were compared to those with none.

RESULTS

The weighted prevalence of moderate-severe depressive symptoms was 24.9% (95%CI = 21.8-28.8) and 16.2%, 22.9%, 46.0% and 51.0% when none, one, two, or three syndemic factors were present, respectively, indicating a dose-response effect. Perception of HIV risk, high level of HIV knowledge, known HIV infection, and health self-rated as poor or very poor were also associated with depressive symptoms.

CONCLUSION

The prevalence of moderate-severe depressive symptoms among MSM in Brazil is high, and selected factors act synergistically in increasing their prevalence. Public health policies should consider holistic depression prevention and treatment interventions for this population.

Safe sexual behaviour among female partners of HIV-infected men in Rio de Janeiro, Brazil

A cross-sectional study was designed to assess safe sexual behaviour among heterosexual couples after the woman learned of her partner's infection with HIV. Female partners who had known their partners' serostatus for at least 4 weeks were eligible for participation. Couples were interviewed separately and independent predictors of safe sexual behaviour were identified using multiple logistic regression. Safe sexual behaviour was defined as no unprotected vaginal, oral, or anal intercourse. Of 328 women, 197 (60%) reported safe sexual behaviour since learning of their partners' infection. Significant independent predictors of safe sexual behaviour included older women (>30 years old) (odds ratio [OR]=1.89; 95% confidence intervals [CI]=1.01–3.51), current negative HIV serostatus (OR=2.72; 95% CI=1.50–4.94), advanced clinical stage of the index case (OR=1.96; 95% CI=1.07–3.59), longer duration of relationship (10+ years) (OR= 2.35; 95% CI=1.15–4.82), fewer sex contacts (<100) (OR=2.01; 95% CI=1.14–3.56), only one lifetime partner (OR=2.29; 95% CI=1.26–4.17), non-smoking (OR=2.67; 95% CI=1.43–4.99), not practising oral sex (OR=3.35; 95% CI=1.82–6.19) and previous HIV testing (OR=2.11; 95% CI=1.09–4.07). In addition, women who had known their partner's infection for longer were less likely to report safe sexual behaviour ( P < 0.001). Our results indicate that among female partners of HIV-positive Brazilian men, learning of their partner's infection does not uniformly result in safe sexual behaviour. Counselling must emphasize disclosure of serostatus to female partners and target couples with short-term relationships, as well as those where the woman has known about her male partner's infection for a long time, because these are the least likely to maintain safe sexual behaviour.

Temporal trends and molecular epidemiology of HIV type 1 infection in Rio de Janeiro, Brazil

HIV-1 molecular epidemiology studies carried out in Rio de Janeiro, Brazil have identified the prevalence of subtypes B, F1 and BF1 recombinants. A high percentage of HIV-1 subtype B isolates in Rio de Janeiro harbor the GWG motif at the V3 tip (B'' variant) instead of the canonical GPG motif (B variant). To trace the dynamics of the HIV-1 variants over time in different exposure categories in Rio de Janeiro, the HIV-1 proviral DNA from heterosexual men (HET) and men who have sex with men (MSM) from two distinct time periods (1990-1992 and 2008-2010) were extracted, and the env-gp120 region was amplified. Neighbor-joining phylogenetic analysis was performed to determine the viral subtype, and Bayesian analysis was used to trace the HIV-1 transmission networks. A predominance of subtype B was observed in both study periods, independent of the exposure risk category. An increase of non-B subtypes was observed in the HET group, but these subtypes were maintained among the MSM group. The distribution of HIV-1 subtype B signatures in the first and second periods studied were, respectively, HET (GPG) [44.8-51.5%], (GWG) [13.8-33.3%], and (GXG) [41.4-15.2%] and MSM (GPG) [34-50%], (GWG) [55.3-30.6%], and (GXG) [10.7-19.4%]. In the first period, an association between GWG and MSM was verified while a significant reduction of this association was observed during the second period. The phylogenetic tree and the BaTS program detected the clustering of isolates only according to the B signatures but not by exposure risk category. Our findings indicate a stable prevalence of HIV-1 subtypes B and F over time in Rio de Janeiro and further suggest that the B'' subclade of subtype B was possibly introduced into the MSM group in this area of Brazil.

Risk factors for breast cancer among pre- or post-menopausal women in Belo Horizonte, Brazil

BACKGROUND

Much controversy has been generated about pre- and post-menopausal breast cancer patients and investigators have sought to identify whether risk factors differ between these two groups. In Brazil, breast cancer is an important cause of death among women and there are few analytical studies concerning pre- or post-menopausal comparisons.

METHODS

A case-control study was carried out at the Federal University Hospital, Belo Horizonte, Brazil, to determine if selected socio-economic and reproductive risk factors for breast cancer differed between pre-menopausal and post-menopausal women. Cases were 300 women with breast carcinoma and controls were 600 women with other benign diseases matched for age and date of diagnosis, admitted to the same hospital during the same period (1978-1987). Univariate and multivariate conditional logistic regression analyses were performed.

RESULTS

Multivariate analysis showed no differences in breast cancer risk in pre- and post-menopausal women (risk factors were similar in direction and magnitude). Occupation, irregular menstrual cycles, parity, history of breast cancer in at least one first-degree female relative, and oral contraceptive use had similar associations in both groups.

CONCLUSIONS

The present study indicates that breast cancer diagnosed before and after menopause has a similar risk profile.

Prognostic aspects of cystic fibrosis in Brazil

Selected prognostic factors were assessed in a cohort of 111 Brazilian children with cystic fibrosis diagnosed between 1 June 1970 and 31 December 1994 and followed in the Pediatric Pulmonology Unit of the Federal University of Minas Gerais Hospital. A standardized protocol was used to collect information retrospectively from medical charts which included date of birth, age at diagnosis, gender, ethnic group, predominant mode of presentation, duration of follow-up, status on 31 December 1994, date of death or date of the last clinical evaluation. The risk of death (univariate and multivariate) was assessed using Cox's proportional hazard model. Mean age at death was higher in males (5.10 years), when the diagnosis was made before the age of 12 months (3.10 years), when clinical presentation was other than respiratory (4.01 years old) and in 'non-whites' (4.86 years old). Age at diagnosis was the only factor associated with death in this population, with both Cox's univariate (RH: 19.4) and multivariate analyses (RH: 17.6; 95% CI: 4.8-64.1). The increased risk of dying in children diagnosed before 12 months of age found in our analysis indicates that they should receive differentiated and intensive multi-professional care.

[Temporal study in AIDS-associated disease in Brazil, 1980-1999]

Trends in annual incidence of reported AIDS-associated opportunistic infections (OI/100 adults > 12 years old) among AIDS cases were estimated at the national level in Brazil from 1980 through May 1999. The analysis included chi-square and linear regression modeling. The opportunistic infections included: candidiasis (CD), tuberculosis (TB), Pneumocystis carinii pneumonia (PCP), neurotoxoplasmosis (NT), Kaposi sarcoma (KS), cryptococcal meningitis (CM), and protozoa infections (PI). The overall cumulative incidence rates/100 reported AIDS cases were: CD = 59, TB = 26, PCP = 23, NT = 15, KS = 5, CM = 4, and PI = 4. Annual trends indicated a statistically significant decline in all OIs. However, in the Northeast and Central-West regions there were increases in TB (b = 0.39) and NT (b = 0.20), respectively. TB showed a higher incidence among individuals with less schooling (< 8 years), while PCP and KS had higher incidence rates among those with 8 or more years of schooling, despite similar downward trends. Access to antiretroviral therapy and OI prophylaxis may partially explain these results. However, data reliability, delay in reporting, OI incidence after AIDS, and reporting and diagnostic criteria are factors that also need to be carefully assessed.

Hepatitis C virus genotypes in hemophiliacs in the state of Minas Gerais, Brazil

BACKGROUND

Hepatitis C virus (HCV) is a positive-strand RNA virus composed of at least 10 genotypes and dozens of subtypes. Six major genotypes can be distinguished by restriction fragment length polymorphism (RFLP) analysis of the amplified 5' noncoding region (NCR) of the genome. The genotypes are unequally distributed throughout the world. Types 1 and 3 are most common in Europe and the United States. Although fewer studies have been performed in Brazil, the pattern seems to mirror that in the other areas. HCV infection is highly prevalent among hemophiliacs and is a major cause of chronic liver disease.

STUDY DESIGN AND METHODS

This study investigated a sample of the hemophiliac population in the state of Minas Gerais, Brazil, by RFLP analysis of the 5' NCR.

RESULTS

It was observed that 84.1 percent were of genotype 1 and 13.6 percent of genotype 3. Sequence analysis of nine isolates confirmed the RFLP results and determined that all of the type 1 isolates belonged to subtype 1a. Phylogenetic analysis by parsimony and distance revealed that lineages of genotypes 1, 2, and 3, and 4 could be separated. The isolates of type 3 from this study were distinct from published sequences, which possibly indicated their different geographical origin.

CONCLUSION

Although the frequency of genotypes observed (types 1 and 3) among hemophiliacs in the state of Minas Gerais was higher than that in the southern part of the country, these frequencies were not different from those in other groups of patients in Brazil and other countries studied. Further investigation is needed of the evidence that the type 3 isolates observed in these studies are significantly different from other isolates previously characterized by sequence analysis.

[Utilization of prescribed drugs by HIV infected individuals: qualitative approach]

OBJECTIVE

The assessment, in its qualitative dimension, of the utilization--by HIV infected individuals--of selected prescribed drugs during the process of the search for and the obtaining of care in public health services in Belo Horizonte, Brazil.

METHODS

Fifty two semi-structured interviews with patients, health care workers and non-governamental organizations volunteers were carried out and 1,079 medical records were reviewed. Data were obtained on the utilization of prescribed drugs by HIV infected individuals, whose first visit to one of the public services studied occurred between January 1989 and December 1992. Problems related to the use of anti-retroviral and/or opportunistic infection medication were identified and a qualitative description of their possible causes and consequences was commented on.

RESULTS

Refusal to use, difficulty in obtaining and in complying with the prescription were the main problems related to anti-retroviral drug use. Causes for such problems included: fear or occurrence of side effects, large number of daily capsules/pills, insufficient and/or irregular distribution of drugs by the public health services and the high cost of anti-retroviral therapy. Based on the reports, the main consequences are likely to be no or late use of anti-retroviral drugs, an increase in resistance and a worsening of the clinical course of the infection. Other problems identified were: self-medication, difficulty in obtaining medications for associated pathologies and in complying with sulfa prescription.

CONCLUSION

A better understanding of the main obstacles and difficulties experienced by the user of the services, from the moment of the prescription and throughout the treatment, may contribute to an improvement in compliance and the availability and adequate distribution of drugs.

[Use of health services and progression of AIDS in persons with HIV infection in Belo Horizonte (Minas Gerais), Brazil]

A nonconcurrent prospective study was done on the relationship between a number of variables and the progression to AIDS among persons diagnosed with the human immunodeficiency virus (HIV). The variables included sociodemographic ones, behavioral ones, and, most importantly, those persons' difficulties in obtaining public health services for HIV/AIDS. The course of the infection was monitored from the first to the last visit to the health services by means of an individual, diagnostic-based classification, using categories established in 1993 by the Centers for Disease Control and Prevention of the United States of America. Participating in the study were 758 patients seen between 1989 and 1992 in the public AIDS referral services of the city of Belo Horizonte (Minas Gerais). All the persons had been diagnosed with HIV and classified in a pre-AIDS stage. Both the patients who developed AIDS during the study as well as those who did not were assessed according to the selected study characteristics. During the study period, 39.5% of the patients developed AIDS. For the group as a whole, the median time without AIDS was 32.4 months. Multivariate analysis showed that the patients who had less risk of developing AIDS were those who had had fewer than 8.8 medical consultations per year (relative risk = 0.36; 95% confidence interval, 0.26 to 0.50) and an interval of at least 6 months between consultations (RR = 0.37; 95% CI, 0.25 to 0.55). The risk was greater in patients age 30 and older (RR = 1.37; 95% CI, 1.03 to 1.84), in those who were not treated with zidovudine (AZT) (RR = 1.91; 95% CI, 1.37 to 2.64), and those who were initially classified in stage "B" of the disease (RR = 4.83; 95% CI, 3.59 to 6.48). The results of this investigation show the dynamics of the supply and demand of services by these patients, and the information will be useful in planning and organizing care for persons with HIV. Recommendations include giving priority to early intervention with a focus on ongoing outpatient care, and more study of the process that persons with HIV follow in seeking and obtaining health care.

Health care utilization and survival among patients with AIDS in Belo Horizonte, Minas Gerais, Brazil

A historical cohort study was conducted in three public AIDS referral services in Belo Horizonte, Minas Gerais, to assess the relationship between health care utilization and patient survival following AIDS diagnosis. A review of medical and laboratory records was performed for HIV-infected patients seeking care for the first time in 1989-92. Among 291 patients initially categorized as 'A' [asymptomatic, acute HIV, or persistent generalized lymphadenopathy-PGL] or 'B' [symptomatic, non-'A', or AIDS-indicator conditions] (CDC, 1992) and who progressed to AIDS, 57.0% died. Mortality rate was 34.9 person-months. Overall median survival time following AIDS diagnosis was 14.3 months. Multivariate analysis showed that lack of AZT use (RR=1.87; 95% CI=1.34-2.61), advanced initial staging (RR=1.68; 95% CI=1.20-2.35), 9 or more inpatient days (RR=1.55; 95% CI=1.11-2.17), and intervals between outpatient visits longer than 6 months (RR=0.30; 95%CI= 0.16-0.56) were associated with death. The analysis suggests that: Patients who used health services more often had poorer prognosis; Patients who received AZT survived longer than those who did not; and variables used to assess health care utilization actually express the end of a process involving seeking and obtaining care.

[Analysis of agreement between coding of underlying cause of death by traffic accidents]

OBJECTIVE

An evaluation of information researched as to basic underlying cause of death by traffic accidents and a comparison with codings attributed on the basis of death certificates.

MATERIAL AND METHOD

The official coding of underlying cause of death on Death Certificates was compared with coding based on primary data obtained from five hospitals and accident reports. Kappa statistics with 95% CI were used to assess the agreement between the two coding systems.

RESULTS

The research covered 1,719 patients. 57 of whom died. Of these 57 deaths, the official coding for 50 was obtained. Data showed an underreporting of deaths by traffic accidents, since 32% of the 50 deaths were coded as non-specific accidents (E928.9) There were also 38% of deaths coded as non-specific traffic accidents (E 819.9). Using primary data, non-specific traffic accidents dropped to 4%, accidents to pedestrians (E814.7) being responsible for 48% of deaths. The Kappa coefficient (0.124), with 95% confidence interval (-.1533-0.4022) was calculated to assess the inter-rater reliability between the two codings, which was considered poor.

CONCLUSION

It is concluded that coroners, who perform autopsies on casualties of traffic accidents, should dedicabe greater effort to filling out Death Certificates correctly.

Benzathine penicillin for unilateral lobar or segmental infiltrates presumptively caused by Streptococcus pneumoniae in children 2-12 years old

A randomized controlled study was carried out to assess the efficacy of a single dose of benzathine penicillin for treating children 2-12 years old with presumed S. pneumoniae pneumonia. One-hundred-and-seventy-six children screened at self-referral pediatric emergency services in Belo Horizonte, Brazil, were randomized to only one injection of benzathine penicillin (n = 93, case-group) or a 7-day procaine penicillin regimen (n = 83, control-group), upon diagnosis of pneumococcal pneumonia based on clinical and radiological characteristics. Follow-up was carried out on the second day after treatment and around the 7th and/or 14th day after treatment allocation. No statistical significant difference was found for sociodemographic, clinical, laboratory or radiographic characteristics among the two groups. Evident or total radiographic clearing was demonstrated for 92.3 and 95.1 per cent of the benzathine penicillin and procaine penicillin groups, respectively (P = 0.54). Benzathine penicillin may be considered an alternative to classic regimens for treating pneumonia due to sensitive strains of S. pneumoniae among children 2-12 years old. Other benefits are its lower cost, better compliance and low rates of adverse reactions.

Postcoital vaginal bleeding as a risk factor for transmission of the human immunodeficiency virus in a heterosexual partner study in Brazil. Rio de Janeiro Heterosexual Study Group

BACKGROUND

Several risk factors for male-to-female human immunodeficiency virus (HIV) transmission are well established, but few studies have examined the role of postcoital vaginal bleeding.

METHODS

Couples recruited from AIDS centers in Rio de Janeiro, Brazil, were interviewed for risk factors and had blood collected for examinations. Eligibility criteria included confirmed HIV positivity for the male partner, aged 18 years of older, heterosexual contact in the past year, and no other risk factor for female partners except sexual contact with the HIV-infected male partner. Logistic regression was used to assess the association between HIV serostatus and risk factors in the female partners.

RESULTS

The prevalence of HIV infection was 47.6% among the 418 women available for analysis. The following factors were independently associated with HIV infection; anal sex (odds ratio [OR], 3.06), condom use during vaginal sex sometimes (OR, 1.42) and rarely to never (OR, 2.00) compared with always, frequency of sexual contacts (> 100 in the previous year) (OR, 1.71), HIV-infected male partners with symptoms of acquired immunodeficiency syndrome (OR, 1.70), and postcoital vaginal bleeding (OR, 1.89). The association of postcoital bleeding and HIV infection was more pronounced among women who did not engage in anal sex.

CONCLUSIONS

The results support previous studies showing that advanced HIV infection in the male partner, anal sex, inconsistent condom use, and frequent sex are associated with HIV infection among the female partners of HIV-infected men. Postcoital vaginal bleeding was also identified as a risk factor for infection. In addition to other established preventive measures, a recommendation for seeking diagnosis and treatment of sexually transmitted diseases that are associated with postcoital bleeding and using water-soluble lubricants during sex to minimize trauma seems prudent.

[Mansonic neuroschistosomiasis: clinical, laboratory and therapeutic aspects]

The authors report 16 patients bearing the meningomyeloradicular form of Mansonic neuroschistosomiasis diagnosed according to clinical, laboratorial and image criteria. Patients have been observed at the Neurology Ambulatory of the Federal University of Bahia, within the period of April/91 to December/93. They have been treated with praziquantel, associated to corticosteroids. The aim has been to evaluate the drug's efficiency and safety in decreasing the neurological signs and symptoms.

HIV infection among female partners of seropositive men in Brazil. Rio de Janeiro Heterosexual Study Group

A heterosexual partner study was carried out in Rio de Janeiro, Brazil, from August 1990 to December 1991. The main objectives were to determine the rate of male-to-female transmission of human immunodeficiency virus (HIV) and to determine risk factors. Male index cases were recruited according to the following criteria: 1) confirmed HIV positivity, 2) 18 years old or older; 3) heterosexual contact within the past year. Only female partners who reported not to have other risk factors but to have had sexual contact with the index case were invited to participate. Couples were interviewed for risk factors and had blood collected for laboratory studies. The overall prevalence of HIV infection was 45 percent among 204 female partners in the study. Using logistic regression, the authors found the following factors to be independently (p < 0.05) associated with HIV infection: 1) anal sex (odds ratio (OR) = 3.74, 95% confidence interval (CI) 1.87-7.45); 2) condom use during vaginal sex sometimes (OR = 1.45, 95% CI 1.07-1.96), rarely (OR = 2.10, 95% CI 1.15-3.83), or never (OR = 3.04, 95% CI 1.23-7.50) as compared with always; 3) frequency of sexual contacts in the year prior to interview (100+) (OR = 2.00, 95% CI 1.03-3.91); and 4) oral contraceptive use (OR = 2.04, 95% CI 0.97-4.29). In addition to a borderline significance of oral contraceptive use, there was a strong suggestion of an interaction with history of sexually transmitted diseases.

A case-control study of risk factors for breast cancer in Brazil, 1978-1987

BACKGROUND

There are still controversies regarding the role of many risk factors assessed for breast cancer worldwide. In Brazil, it represents a major cause of death among women but yet few analytical studies have been published to date.

METHODS

The association of selected factors with breast cancer was assessed in a case-control study of 300 women, aged 25-75 years, treated at the Federal University Hospital, Belo Horizonte, Brazil, from 1978 to 1987. In all, 300 cases with diagnosed breast carcinoma were compared with 600 controls matched on age and date of diagnosis. Socio-economic, demographic and reproductive factors were analysed.

RESULTS

Multiple logistic regression analysis showed the following factors to be independently associated with increased risk of breast cancer: a) monthly family income (odds ratio [OR] = 1.69, 95% confidence interval [CI]: 1.18-2.42); b) being a housewife (OR = 2.86, 95% CI: 1.83-4.47; c) parity of less than six deliveries and nulliparous women (OR = 5.06, 95% CI: 3.01-8.52 and OR = 2.42, CI: 1.64-3.59, respectively); d) history of breast cancer among first degree female relatives (OR = 9.35, 95% CI: 3.22-27.14); and e) oral contraceptive use (OR = 1.81, 95% CI: 1.15-2.85). Irregular menstrual cycle (OR = 0.44, 95% CI: 0.25-0.75) was associated with breast cancer as a protective effect.

CONCLUSIONS

The study has confirmed most risk/protective factors previously demonstrated elsewhere in the world and provides clear documentation of breast cancer epidemiology in Brazil.

[The epidemiological aspects of HIV/AIDS in Brazil]

A trend analysis of the AIDS epidemics in Brazil is presented, emphasizing temporal changes among the population groups most affected. Regional comparisons as well as projections of the extension of HIV infection and AIDS cases are also reported. Amongst the most relevant conclusions the alarming increase of cases in heterosexual populations and intravenous drug users is emphasised, specially in the southeast region.

Exposure to acellular blood products and risk of HIV infection in hemophiliacs from Belo Horizonte, Brazil

Results of a HIV prevalence study conducted in hemophiliacs from Belo Horizonte, Brazil are presented. History of exposure to acellular blood components was determined for the five year period prior to entry in the study, which occurred during 1986 and 1987. Patients with coagulations disorders (hemophilia A = 132, hemophilia B = 16 and coagulation disorders other than hemophilia = 16) were transfused with liquid cryoprecipitate, locally produced, lyophilized cryoprecipitate, imported from São Paulo (Brazil) and factor VIII and IX, imported from Rio de Janeiro (Brazil), Europe, and United States. Thirty six (22%) tested HIV seropositive. The univariate and multivariate analysis (logistic model) demonstrated that the risk of HIV infection during the study period was associated with the total units of acellular blood components transfused. In addition, the proportional contribution of the individual components to the total acellular units transfused, namely a increase in factor VIII/IX and lyophilized cryoprecipitate proportions, were found to be associated with HIV seropositivity. This analysis suggest that not only the total amount of units was an important determinant of HIV infection, but that the risk was also associated with the specific component of blood transfused.

A clinical epidemiologic study in a schistosomiasis mansoni endemic area (Tuparecê, Minas Gerais)

A population-based clinical epidemiologic study on schistosomiasis mansoni was carried out in Tuparecê, Minas Gerais. The patients were interviewed for symptoms, water contact, past history and examined for spleen and liver enlargement. From the 830 people registered in the census, 777 (93.6%) had their stools examined (Kato-Katz method) and 696 (83.9%) were clinically evaluated. The overall index of Schistosoma mansoni infection was 43.2%. Significant and increased infection risks could be detected in the young age group (2-14 years old) regarding occupation, time of residence in the area and frequency of water contact. Bloody stools were significantly more prevalent among positives, while diarrhea was significantly more prevalent among those negative. The area was shown to have a low morbidity as well as a low intensity of infection measured by the number of S. mansoni eggs per gram of feces. A close correlation was found between water contact pattern and the age prevalence curve. It has emphasized the importance of habits in determining prevalence rates, besides suggesting that schistosomiasis mansoni in the area is manifested as a light and somewhat harmless infection with little consequence for the population as a whole.

[Clinico-epidemiological study of schistosomiasis mansoni in school children of Ilha, municipality of Arcos, MG (Brazil) 1983]

Foi realizado um estudo clínico-epidemiológico da esquistossomose em escolares (6 - 14 anos) da Ilha, em Minas Gerais (Brasil). Foram feitos exame parasitológico de fezes pelo método de KATO-KATZ e exame clínico em, respectivamente, 86,7 e 85,4% da população escolar. Foi realizado levantamento sócio-econômico e foram pesquisados os sinais e sintomas apresentados pelos pacientes e seus contatos com águas naturais. O índice de infecção pelo Schistosoma mansoni foi 32,7%, predominaram as baixas contagens de ovos nas fezes (89,0% dos pacientes eliminavam menos de 500 ovos/grama de fezes) e o índide de esplenomegalia foi 7,7%. Os pacientes positivos (com ovos de S. mansoni nas fezes) foram comparados aos negativos (sem ovos nas fezes e com intradermoreação negativa), verificando-se que a infecção pelo S. mansoni era significativamente mais freqüente entre os trabalhadores rurais, entre os que residiam em casas de pior qualidade e entre aqueles cujos chefes de família eram analfabetos. Constituíram os maiores fatores de risco para a infecção pelo S. mansoni nesta área: a) ter contatos com águas naturais para trabalhar na lavoura (Odds Ratio = 18,08); b) ter contatos diários com águas naturais (OR = 13,82) e c) ter contatos com águas naturais para pescar, nadar e/ou brincar (OR = 7,75 e 5,51, respectivamente). Os autores levantam a hipótese de que a transmissão da esquistossomose nesta localidade não ocorre no peridomicílio, mas sim nas lagoas próximas à Ilha e nas plantações agrícolas, provavelmente nas culturas de arroz de várzea.