Changes in malaria patterns in Brazil over 28 years (1990-2017): results from the Global Burden of Disease Study 2017.

Background: This study presents the malaria burden in Brazil from 1990 to 2017 using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), by analyzing disease burden indicators in federated units of the Legal Amazon and Extra-Amazon regions, as well as describing malaria cases according to Plasmodium species occurring in the country.

Methods: We used estimates from the GBD 2017 to report years of life lost due to premature death (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs) for malaria in Brazil, grouped by gender, age group, and Brazilian federated unit, from 1990 to 2017. Results are presented as absolute numbers and age-standardized rates (per 100,000 inhabitants) with 95% uncertainty intervals (UI).

Results: At the national level, the age-standardized DALYs rate due to malaria decreased by 92.0%, from 42.5 DALYs per 100,000 inhabitants (95% UI 16.6-56.9) in 1990 to 3.4 DALYs per 100,000 inhabitants (95% UI 2.7-4.7) in 2017. The YLLs were the main component of the total DALYs rate for malaria in 1990 (67.3%), and the YLDs were the main component of the metric in 2017 (61.8%). In 2017, the highest sex-age DALYs rate was found among females in the "< 1-year-old" age group, with a 6.4 DALYs per 100,000 inhabitants (95% UI 1.8-14.7) and among males in the age group of "20 to 24 years old", with a 4.7 DALYs per 100,000 inhabitants (95% UI 3.3-9.9). Within the Brazilian Amazon region, the three federated units with the highest age-standardized DALYs rates in 2017 were Acre [28.4 (95% UI 14.2-39.1)], Roraima [28.3 (95% UI 13.5-40.2)], and Rondônia [24.7 (95% UI 11.4-34.8)]. Concerning the parasite species that caused malaria, 73.5% of the total of cases registered in the period had Plasmodium vivax as the etiological agent.

Conclusions: The results of the GBD 2017 show that despite the considerable reduction in the DALYs rates between 1990 and 2017, malaria remains a relevant and preventable disease, which in recent years has generated more years of life lost due to disability than deaths. The states endemic for malaria in the Amazon region require constant evaluation of preventive and control measures. The present study will contribute to the direction of current health policies aimed at reducing the burden of malaria in Brazil, as knowing the geographical and temporal distribution of the risk of death and disability of this disease can facilitate the planning, implementation, and improvement of control strategies aimed at eliminating the disease.