Stroke in the Rain Forest: Prevalence in a Ribeirinha Community and an Urban Population in the Brazilian Amazon

Abstract

Background: Our objective was to determine the cerebrovascular prevalence in a town in the Brazilian Amazon basin and compare the ribeirinhos (riparians) to the urban population in the same municipality. Methods: From May to October 2011, 6,216 residents over 35 years of age in the town of Coari were interviewed using a screening questionnaire, the Stroke Symptom Questionnaire. Cerebrovascular prevalence rates (PRs) from the door-to-door surveillance were calculated according to the location of the home. Results: Respondent totals were 4,897 in the urban area and 1,028 in the rural area. The crude prevalence of stroke was 6.3% in rural and 3.7% in urban areas with differences maintained after sex and age adjustment. Among stroke cases, the ribeirinhos were those with less access to medical care in comparison to the urban area (32.1 vs. 52.5%, p = 0.01), and a positive association between rural area and no medical care for stroke remained (PR, 1.33; 95% confidence interval, 1.03-1.71), independently of age, sex, education and functional impairment. Conclusions: This study provides the first population-based cerebrovascular prevalence comparison between an urban and a rural population in the Amazon rain forest. The PRs were higher in the ribeirinha compared to the urban population in the same municipality.