Mortality Time Trend for Major Viral Pathogens Causing Acute Respiratory Failure in Brazilian Children and Adolescents Before and During the SARS-Cov-2 Pandemic

Abstract

Background – Little is known about the time trend in mortality rates due to respiratory viruses other than SARS-CoV-2 and seasonal influenza among Brazilian children and adolescents. Methods – Study outcomes were mortality rates due to influenza A, influenza B, respiratory syncytial virus, metapneumovirus, rhinovirus, parainfluenza, adenovirus, and bocavirus, for age groups <5, 5-9, and 10-19 years of age, in Brazil, over the 2009-2022 period. Secondary data from the Brazilian Ministry of Health were analyzed by interval regression, bounded between reported deaths and estimated upper limit of this number, which took into account the underestimation of deaths, the error in attributing its causes in official records, and the variation due to Poisson distribution. Results - For all viruses, mortality varied little among the children under five years of age, and increased gradually among the 5-10 and 11-19-years old. The highest average mortality rates per million inhabitants over the 2009-2022 period were estimated for respiratory syncytial virus (1.04), with the lowest values for parainfluenza (0.54) and influenza B (0.55), and intermediate values in the range of 0.90 to 0.95 for influenza A, bocavirus, metapneumovirus, rhinovirus, adenovirus, and other respiratory viruses except SARS-Cov-2. Age groups of 5-9 and 10-19 years of age had similar mortality rates and were by far the largest contributors to the overall mortality rates for all viruses analyzed. Conclusion - Schoolchildren mortality due to respiratory viruses in Brazil has been rising for at least five years before the COVID-19 pandemic, and remained elevated during the pandemic. In addition to SARS-CoV-2 and seasonal influenza, respiratory syncytial virus, metapneumovirus, rhinovirus, parainfluenza, adenovirus, and bocavirus, all showed a non-ignorable impact on mortality in this age group.