Abstract

Background and Aims Guillain-Barr & eacute; syndrome (GBS) is the leading cause of acute flaccid paralysis. A Chilean study for 2001-2012 reported an age-standardized incidence of 2.10 per 100 000. We updated nationwide GBS incidence for 2013-2022 by sex, age, and macrozone. Methods We conducted a retrospective, population-based analysis of the Chilean Department of Statistics and Health Information (DEIS) hospital-discharge database. Cases were identified with the ICD-10 code G61.0 and deduplicated. Incidence rates (IRs) per 100 000, using official mid-year populations, were age-standardized to the World Health Organization standard and stratified by sex, 10-year age groups, and five macrozones. Results We identified 5096 discharges. The period crude IR was 2.73, and the age-standardized IR was 2.60 per 100 000. Annual standardized IRs ranged from 3.15 (2013) to 2.03 (2020). Men comprised 58.6% of cases; period IRs were 3.25 in males versus 2.34 in females. Age-specific IRs rose from 2.47 at 0-9 years to 5.76 at 70-79, then declined (3.63 at 80-89; 1.04 at >= 90). Regionally, IRs were lowest in the Far North (1.86) and North (2.26), intermediate in the Central zone (2.51), and highest in the South (4.55) and Far South (4.86). Interpretation In 2013-2022, Chile's GBS incidence remained high by international standards and higher than in 2001-2012, with persistent male predominance, a peak among older adults, and a southward gradient. These updated background rates inform service planning, surveillance, and vaccine-safety assessment, and support integrated epidemiologic-microbiologic studies across macrozones.