Hepatitis of unknown etiology in children in Brazil: A new challenge or the usual scenario ?

Abstract

An outbreak of acute hepatitis of unknown etiology in children was recently reported worldwide. We aimed to describe the burden of hospitalizations due to hepatitis of unknown etiology in children/adolescents in Brazilian public hospitals. We retrieved a database of all hospitalizations in the Brazilian Unified Health System (SUS) from January/2019 to February/2022 using the "microdatasus" R package. Hepatitis of unknown etiology was defined by the following International Classification of Diseases [ICD-10] codes: B19, B19.0, B19.9, K72.0, K72.9, K75, K75.9, R94.5, or R93.2. The incidence rates (95% confidence interval, IC) per 1,000 all-cause hospitalizations in different age strata [< 6 years; 6-11 years and 12-17 years] were estimated. A total of 94,198 hospitalizations due to hepatic or infectious diseases with potential liver injury were analyzed. Of them, 1,535 children/adolescents [48.2% male sex, 41.6% aged < 6 years] were hospitalized with hepatitis with unknown etiology. The top ICD-10 codes were B19.9 [unspecified viral hepatitis without hepatic coma; 39.9% (n=612)], K72.9 [hepatic failure, unspecified; 29.8% (n=457)], and K72.0 [hepatic failure, not elsewhere classified; 14.5% (n=223)]. A total of 8.5% (n=131) of individuals required liver transplantation and 7.0% (n=107) died during the hospital-stay. In 2021, the incidence rates (95% CI) of hospitalizations for hepatitis with unknown etiology were 7.80 (7.63-7.98), 17.96 (17.46-18.48) and 13.28 (12.95-13.62) per 1,000 all-cause hospitalizations in subjects aged < 6 years, 6-11 years and 12-17 years-old, respectively. Similarly, the incidence rates of hospitalization due to hepatitis with unknown etiology per 1,000 all-cause hospitalizations (CI95%) in January-February/2022 were 7.52 (7.11-7.94), 16.82 (15.68-18.03), and 13.96 (13.10-14.85) for children/adolescents with age < 6 years, 6-11 years, and 12-17 years, respectively. A non-negligible number of hospitalizations due to hepatitis with unknown etiology in children/adolescents was observed in the last years in Brazil. Up to 15% of those cases needed liver transplantation or died.