Mortality in children under five years old in Brazil: evolution from 2017 to 2020 and the influence of COVID-19 in 2020

OBJECTIVE: To analyse the mortality trends in children under five years old in Brazil from 2017 to 2020 and the influence of COVID-19 in 2020. METHODS: A retrospective study employing secondary data from the Brazilian Mortality Information System. Deaths according to cause were extracted and disaggregated into early, late, postneonatal, and 1 to 4-year-old periods. Corrected mortality rates per 1,000 live births and relative risk ratio for the cause of death were calculated. RESULTS: There were 34,070 deaths, being 417 (1.2%) from COVID-19 in 2020. COVID-19 mortality was 0.17 per 1000 live births, reaching 0.006 in the early neonatal period, 0.007 in the late neonatal, 0.09 in the postneonatal, and 0.06 in 1 to 4-year-old. Mortality decreased mostly for some diseases that originated in the perinatal period, congenital anomalies, diseases of the respiratory system and external causes, in this order. In 2020, the highest rate was in the early neonatal period, with a fall from 7.2 to 6.5, followed by the postneonatal (3.9 to 3.4) and late neonatal (2.3 to 2.1). Among children aged 1 to 4-year-old, external causes had the highest proportional rate, and diseases of the respiratory system showed the highest decline. CONCLUSION: The mortality rate declined from 2017 to 2020, and this variation was higher in the early neonatal period. The risk of death from COVID-19 was 14 times higher in the postneonatal period and 10 times higher in children aged 1 to 4 year-old compared to the early neonatal period.