Hospitalizations for schistosomiasis in Spain by sex: a population-based study using the national hospital discharge database (2016–2023)

BACKGROUND: Schistosomiasis is an emerging imported parasitic disease in Europe, but information on its clinical burden among hospitalized patients in non-endemic countries remains limited. OBJECTIVE: To describe the epidemiology, clinical characteristics, complications, and outcomes of patients hospitalized with schistosomiasis in Spain using nationwide hospital discharge data, with a focus on sex-related differences. METHODS: We conducted a retrospective observational study using the Spanish National Hospital Discharge Database (SNHDD). All hospitalizations with schistosomiasis (ICD-10: B65) recorded between 2016 and 2023 were included. Demographic characteristics, country of birth, clinical conditions, complications, and outcomes were analyzed. Urogenital, hepatosplenic, and intestinal complications were identified using ICD-10 codes. RESULTS: A total of 710 hospitalizations were identified; 550 (77.5%) occurred in men. Women were older than men (median age 46 vs. 34 years; p < 0.001) and had longer hospital stays (9 vs. 7 days; p = 0.041). Urogenital complications were more frequent in men, including bladder cancer (5.1% vs. 0.6%; p = 0.012), hematuria (5.8% vs. 1.3%; p = 0.017), cystitis (6.7% vs. 0.6%; p = 0.003), and obstructive uropathy (5.3% vs. 0%; p = 0.003). Male sex was independently associated with bladder cancer (aOR 16.31, 95% CI 2.12-125; p = 0. 0.007) and cystitis (adjusted OR 9.49, 95% CI 1.28-70; p = 0.028). Age was positively associated with bladder cancer (aOR 1.05, 95% CI 1.043-1.08; p < 0.001), and a lower probability of hematuria. (aOR 0.96, 95% CI 0.93-0.99; p = 0.005. In contrast, hepatosplenic complications were more frequent in women, including portal hypertension (12.5% vs. 4.5%; p < 0.001), esophageal varices (9.4% vs. 1.8%; p < 0.001), splenomegaly (5.6% vs. 1.5%; p = 0.002), and cirrhosis (6.3% vs. 2.7%; p = 0.033). Female sex was independently associated with portal hypertension (aOR 3.10, 95% CI 1.60-5.99), esophageal varices (aOR 7.11, 95% CI 2.92-17.30), and splenomegaly (aOR 5.46, 95% CI 1.88-15.92). ICU admission (8.6%) and in-hospital mortality (1.8%) did not differ significantly by sex. The overall hospitalization rate was 20 per million hospital admissions and was higher in men than in women (32.1 vs. 8.7 per million). CONCLUSION: Hospitalizations for schistosomiasis in Spain predominantly occur in men and are mainly associated with imported infections. Men more frequently present with urogenital complications, whereas women show a higher burden of hepatosplenic manifestations. These findings highlight the importance of increasing clinical awareness and implementing targeted screening and early diagnostic strategies in at-risk populations in non-endemic settings.