Influenza is an acute respiratory infection with high transmissibility that can progress to severe complications, especially in vulnerable populations. Analyzing hospital data allows monitoring of the disease burden across regions, supporting epidemiological surveillance and public health planning. This study aims to analyze the number of hospitalizations and deaths due to influenza in Brazil’s Northern Region. Descriptive study based on secondary data extracted from SIH/SUS via TABNET/DATASUS. Hospital admissions with an influenza diagnosis (ICD-10: J10 and J11) from January 2023 to May 2025 were included for the seven states in Northern Brazil. Variables analyzed were total hospitalizations and recorded deaths. Ethics approval is not required for studies using secondary data. During the study period, 9,543 influenza hospitalizations were recorded in the Northern Region, with 172 deaths, yielding a regional average case-fatality rate of 1.8%. Pará accounted for most hospitalizations (5,088; 53.3%) and the highest absolute number of deaths (70), followed by Amazonas (1,694 hospitalizations and 19 deaths) and Acre (1,050 hospitalizations and 52 deaths). Although Acre represented only 11% of regional hospitalizations, it accounted for more than 30% of deaths, with a case-fatality rate of 4.95%, the highest among the states. This discrepancy suggests possible local weaknesses in the response to the disease. The states with the lowest number of hospitalizations were Roraima (19 hospitalizations, 1 death) and Amapá (199 hospitalizations, with no deaths recorded). The data show a substantial burden of influenza hospitalizations in the Northern Region, concentrated in the most populous states. However, Acre’s high case-fatality rate, far above the regional average, is notable and suggests an urgent need for deeper investigation. Factors such as delayed access to healthcare, limitations in hospital infrastructure, or gaps in active surveillance may be contributing. Therefore, prevention strategies, early diagnosis, and access to intensive care are essential to reduce severe outcomes, especially in more vulnerable areas.
Farias et al. (Sun,) studied this question.