Multivariate analysis of schistosomiasis in the state of Minas Gerais: principal component analysis

Abstract

Introduction: Schistosomiasis mansoni is a neglected disease in Brazil, therefore, related to poverty and lack of sanitary conditions. Occurs in the coastal region of the northeast and spreads inland from the state of Bahia, reaching Minas Gerais. Objective: To group, through component analysis, the main variables related to schistosomiasis in factors that may explain data variance. Methods: Reports of schistosomiasis between the years 2007 to 2014 were evaluated, considering averages per 100 thousand inhabitants. The variables: education, health, economy, infrastructure and sanitation, population, altimetry and Human Development Index (HDI), were obtained from Atlas Brazil; the schistosomiasis notification data were obtained from the injury and notification information system (SINAN). Statistical analysis was based on the analysis of main components, aiming to identify the key factors that contribute most significantly to data variance. Results: Considering the proposed criteria, three factors explained more than 76% of the variance, the first one related to the following variables: illiteracy rate at 18 years of age or more, no elementary education, child mortality, extremely poor, vulnerable to poverty, inadequate sanitary sewage and rural population. The second was related to the sanitary sewage variable and the third factor to the altitude variable. Conclusion: The variables associated with factors, especially those based on the social determinants of health; show a strong relation with the occurrence of schistosomiasis. The contribution of the study reminds us of the possibility of grouping variables into factors that behave synergistically and favor the incidence of parasitosis.