Prevalence of trachoma in Brazilian schoolchildren

Abstract

OBJECTIVE: To estimate the prevalence and describe the distribution of trachoma among schoolchildren in Brazilian municipalities. METHODS: Cross-sectional study, using cluster sampling, of the schoolchildren population of the Brazilian municipalities with Human Development Index - Municipal lower than the national average. This trachoma prevalence survey was conducted by the Ministry of Health, in the period 2002-2007. There were 119,531 schoolchildren selected from 2,270 schools located in 1,156 municipalities. The selected schoolchildren underwent an external ocular examination, with a magnifying glass (2.5X), to detect clinical signs of trachoma according to the WHO criteria. The prevalence of trachoma, by state and national level, and their respective 95% confidence intervals were estimated. Chi-square and Chi-square for trends tests were used to compare categorical variables. RESULTS: There were 6,030 cases of trachoma detected, resulting in a prevalence of 5.0% (95%CI 4.5;5.4). There was no significant difference between the sexes. The prevalence of trachoma was 8.2% among children under 5 years of age, decreasing among higher age groups (p < 0.01). There was a significant difference in prevalence between urban and rural areas, 4.3% versus 6.2% respectively (p < 0.01). Cases were detected in 901 municipalities (77.7% of the sample), in all regions of the country. In 36.8% of the selected municipalities, the prevalence was higher than 5%. CONCLUSIONS: The study shows that trachoma is a significant public health problem in Brazil, contradicting the belief that the disease had been controlled in the country. The survey provides a baseline for evaluating planned interventions aimed at achieving the goal of global certification of elimination of trachoma as a cause of blindness in Brazil by 2020.