Coronavirus Disease 2019 Population-based Prevalence, Risk Factors, Hospitalization, and Fatality Rates in Southern Brazil

Picon, Rafael V.; Carreno, Ioná; da Silva, André Anjos; Mossmann, Márcio; Laste, Gabriela; Domingues, Guilherme de Campos; Heringer, Lara Faria Fernandes; Gheno, Brenda Rodrigues; Alvarenga, Leticia Leão; Conte, Magali

OBJECTIVES: To assess population-based prevalence, risk factors, hospitalization, and infection fatality rates (IFR) associated with COVID-19. METHODS: We conducted two household surveys among the non-institutionalized adult population from May 30 to June 17, 2020, in Lajeado, an 84,000-inhabitants industrial city in southern Brazil. Primary outcome was prevalence of SARS-CoV-2 infection. Secondary outcomes were COVID-19 hospitalizations and deaths occurring up to June 20, 2020. We summarized prevalence rates across surveys with meta-analysis. We assessed age-range IFR and hospitalization rate and regressed these rates over age strata using nonlinear coefficients of determination (R(2)). RESULTS: Summarized overall prevalence was 3.40% (95% CI, 2.74 to 4.18), 34% lower in elderly ≥60 years-old. IFR ranged from 0.08% (0.06 to 0.11) to 4.63% (2.93 to 7.84) in individuals 20 to 39 years-old and ≥60 years-old, respectively. R(2) for exponential age-dependent hospitalization rate and IFR were 0.98 and 0.93 (both p-values <0.0001), respectively. CONCLUSIONS: This is the first population-based study in Brazil to estimate COVID-19 prevalence, hospitalization and fatality rates per age stratum. Rates were largely age-dependent. Household contacts and MPP workers are at higher risk of infection. Our findings are valuable for health-policy making and resource allocation to mitigate the pandemic.