Trends and risk factors associated with severity and mortality related to hepatitis A in French hospitals: a national population-based study, 2013 to 2024

Abstract textO_ST_ABSBackgroundC_ST_ABSAs hepatitis A (HA) incidence declines in Europe and infections occur later in life, clinical presentations may worsen, particularly during outbreaks involving adults. AimWe analysed temporal trends and factors associated with severe disease and mortality among patients hospitalised for HA in France between 2013 and 2024. MethodsICD-10 codes B150 or B159 as primary discharge diagnosis were used to identify HA cases from the National Discharge Data Set. Severity (hepatic and/or extrahepatic organ failure within 12 weeks post-admission) and mortality were analysed using adjusted odds ratios in original and propensity-matched samples. Trends were assessed across five periods covering the 2017 epidemic and COVID-19, with 2013-2016 as reference. ResultsAmong 7,928 cases (60.6% male; median age 30) 29.1% developed severe HA, and 1.43% died. Risk of severe HA increased with age (+17% of risk per decade, p < 0.001), male sex (+39%, p < 0.001), smoking (+25%, p=0.024), liver risk factors (+32%, p=0.026), and cirrhosis (+48%, p = 0.024). Risk of death increased with cirrhosis (3.55-fold, p < 0.001) and high Charlson Comorbidity Index (CCI) (9.95-fold, p < 0.001), but not with advanced age. Compared with 2013-2016, severe HA increased by 60% (p<0.001) and case fatality increased 2.22-fold (p=0.003) in 2021-2024. ConclusionsHA severity and mortality have increased in France over the last decade, with advanced age and male sex increasing severity but not mortality, and high CCI limiting access to organ support, thereby increasing mortality in frail patients. Our findings highlight the need for targeted prevention and optimized care strategies for high-risk groups.