Analysis of the malaria profiles in high-risk incidence municipalities in the Brazilian Amazon using Principal Component Analysis in the period 2011-2013 and 2017-2019

BackgroundMalaria still is one of the most relevant infectious diseases in Brazil with 184,869 cases in 2019 and 62.8% of these cases occurred in only 6.2% of municipalities that had high transmission. The incidence of malaria is influenced by environmental, socioeconomic, demographic, and structural factors (organization and effectiveness of health services, land use, and infrastructure). MethodsWe use data from the Malaria Epidemiological Surveillance System aggregated by period and municipality, maintained by the Ministry of Health, from 2007 to 2019, and combine it with data from the National Institute for Space Researchs - Satellite Monitoring of Brazilian Amazon Forest Deforestation Project, 2010 Demographic Census Microdata and Registry of Health Establishments to analyze socioeconomic, demographic, environmental and health factors in two distinct periods. We use the Principal Component Analysis algorithm to create different principal components characteristics patterns in high-risk municipalities. ResultsThe Principal Component Analysis allowed the creation of three profiles of high-risk municipalities combining the contribution of different demographic, socioeconomic, environmental, and health characteristics with the contribution of the municipalities in each principal component. The first group with a vulnerability profile, that is, high-risk municipalities with cases more associated with vulnerability characteristics, the second group is one with a profile of occupation and working age, of high-risk municipalities with cases more related to socioeconomic and demographic variables linked with specific occupations and a working-age population and the third group with municipalities that has a mixed profile associated with different characteristics related to of P. falciparum in contrast of P. vivax cases, such as the municipality of Rio Preto da Eva, which for the cases of P. vivax, may be more related to children under 5 years and differently, P. falciparum in this municipality could be more related to gold panning, deforestation and the presence of large bodies of water. ConclusionsThere are particularities in socioeconomic, demographic, environmental, and health characteristics for infection by both types of Plasmodium and high-risk municipalities that become necessary to understand the differences in the profile of the population affected by malaria together with the environment in which they live, the weather, forest, hydrography and health conditions to assess the structure in these regions, in addition to analyzing the cases of P. falciparum separately from the cases of P. vivax, showing us that understand the socio-environmental determinants at the local level is essential for the success of malaria prevention and control strategies. Author SummaryLuciana C. Alves is an Associate Professor at the Institute of Philosophy and Human Sciences (IFCH) at the University of Campinas (Unicamp) and research scientist at the Population Studies Center Elza Berquo (Nepo) and Chair of the Department of Demography at the University of Campinas. Natalia M. Arruda is a doctoral student in Epidemiology at the National School of Public Health/Fiocruz. Vinicius S. Maia is a doctoral student at the Centre for Economic Demography at Lund University. Bianca C. Carlos is an assistant researcher at the Population Studies Center Elza Berquo (Nepo)/Unicamp. Carlos E. Beluzo is a Professor at the Federal Institute of Sao Paulo and a doctoral student at the Institute of Philosophy and Human Sciences (IFCH) at the University of Campinas (Unicamp).