Human rabies is an acute viral disease with near-100% lethality, making it an ideal model for evaluating the effectiveness and accuracy of health notification systems. Records in the Notifiable Diseases Information System (SINAN) are expected to match deaths reported in the Mortality Information System (SIM). Discrepancies between these systems may reflect operational failures, underreporting, data loss, or inefficiency in epidemiological surveillance, compromising disease control and public policy formulation. The objective of this study was to evaluate the accuracy of SINAN and SIM in human rabies surveillance by analyzing discrepancies between confirmed cases and recorded deaths. A descriptive ecological study using confirmed human rabies cases and deaths extracted from SINAN and SIM, available from the Department of Informatics of the Unified Health System (DATASUS). Time series from 2008 to 2023 were analyzed, stratified by Brazilian regions. Percentage error between expected and recorded deaths was calculated using Excel software. Between 2008 and 2023, SINAN recorded 48 confirmed human rabies cases in Brazil, while SIM recorded 37 deaths, revealing notification discrepancies. The mean underreporting percentage error was −23%, with the Northeast region standing out (−37%), where 24 confirmed cases and 15 recorded deaths indicated that more than one-third of deaths were not correctly recorded. In the Southeast region, a positive error of 40% was observed (3 confirmed cases and 5 recorded deaths), possibly due to deaths recorded without prior diagnosis, failures in epidemiological investigation, or underreporting of cases during life. Years such as 2014, 2015, 2019, 2020, 2021, and 2023 showed absence of deaths in SIM despite confirmed cases in SINAN, reinforcing weaknesses in system integration and surveillance. These findings indicate the need for system integration, professional training, and strengthening of surveillance and notification. Discrepancies in human rabies notification in Brazil reveal weaknesses in surveillance systems. Given the almost absolute lethality of the disease, such errors are unacceptable and require urgent interventions to ensure data reliability, which is the fundamental basis for effective public health actions and rabies control in the country.
Sombrio et al. (Sun,) studied this question.