Climatic and Geographic Variations of Antecedent Infections in Guillain–Barré Syndrome: A Long‐Term Longitudinal Analysis From Bangladesh

ABSTRACT Background and Aims Guillain–Barré syndrome (GBS) is an acute post‐infectious autoimmune neuropathy, frequently triggered by antecedent infections. While climate influences the seasonality and distribution of infections, its role in triggering GBS remains underexplored. We aimed to evaluate the impact of climatic and geographical variations on infections preceding GBS in Bangladesh. Methods Five hundred and sixty‐six GBS patients were enrolled from four prospective cohorts (2010–2024). Antecedent events were recorded within 4 weeks of weakness onset. Meteorological data were retrieved from the World Bank's Climate Change Knowledge Portal (2010–2020) and Bangladesh Meteorological Department (2021–2024). Patients were categorized by regions (northern, central, southwestern, and eastern), seasons (summer, autumn, winter, spring). Analysis were performed in R using chi‐square, t ‐tests, Kaplan–Meier, and multivariable logistic regression. Results Among 566 patients (69% male, median age: 31 years). Antecedent events were reported in 70%, predominantly GE (46%) and URTI (19%). The axonal subtype predominated (64%), with 31% receiving intravenous immunoglobulin or plasma exchange. GE was associated with higher disability (GBS‐DS = 4, 61% vs. 46%, p = 0.014 ) and cranial nerve involvement (57% vs. 43%, p = 0.017) compared to URTI. GE peaked during spring (31%) and URTI in winter (35%, p = 0.009), with no subtype‐season association after adjustment ( p = 0.180). GE occurred more at higher mean temperatures (26.06°C vs. 25.05°C, p = 0.048) and at higher precipitation (162.65 mm vs. 105.04 mm, p = 0.0001). GE cases correlated positively, while URTI inversely, with temperature ( r s = 0.185) and precipitation ( r s = 0.053). Interpretations Warmer temperature and higher precipitation, particularly spring and summer, favor GE‐related GBS. Further studies are warranted to explore climate‐sensitive infectious triggers of GBS in Bangladesh.