Pediatric brucellosis: predictors of hospitalization, complications, and relapse in a nationwide multicenter cohort.

Brucellosis is a common zoonosis worldwide, yet large-scale pediatric data are scarce. This nationwide multicenter study from Türkiye, a highly endemic country, aimed to characterize pediatric brucellosis and identify independent risk factors for complications, relapse, and hospitalization. A retrospective cohort was conducted across 32 hospitals between January 2019 and June 2024. Children aged 0-18 years with confirmed brucellosis were included. Data were analyzed by multiple backward logistic regressions, with Firth penalization for the complication and relapse models. A total of 1052 children were included (median age 12 years; 69.9% male). Complications occurred in 87 patients (8.3%), most frequently osteoarticular (spondylitis, sacroiliitis, and osteomyelitis), whereas neurobrucellosis was rare (0.9%); relapse occurred in 34 patients (3.2%). Complications were independently associated with headache (adjusted OR 3.566, 95% CI 1.861-6.637), arthralgia/arthritis, culture positivity, night sweating, and myalgia. Relapse was independently associated with female sex (adjusted OR 3.675, 95% CI 1.617-8.568), whereas treatment compliance was protective (adjusted OR 0.254, 95% CI 0.092-0.857). Hospitalization (34.1%) was independently associated with headache, diarrhea, hepatomegaly, lymphadenopathy, fever, elevated CRP, and lower hemoglobin, whereas diagnosis through household contact screening was protective.

Conclusion

Pediatric brucellosis in Türkiye generally follows a favorable course, with low complication and relapse rates. Readily identifiable musculoskeletal and constitutional symptoms at presentation may help predict complicated disease, while treatment adherence remains the key determinant of relapse. Early detection through household contact screening may reduce disease burden in endemic regions. What is Known: • Brucellosis is a common zoonosis with limited pediatric data worldwide. Early detection and treatment adherence are critical for favorable outcomes. • Complications and relapse are recognized but poorly defined in children What is New: • This is one of the largest nationwide pediatric brucellosis cohorts reported to date, including 1052 children. Household contact screening shown protective against hospitalization. • Treatment adherence, rather than disease severity or complications, was the key determinant of relapse in pediatric brucellosis.