Tuberculosis in children under 5 years of age in a low-burden setting: sociodemographic and epidemiological characteristics and healthcare utilization over a 10-year period (2010–2021)

PURPOSE: To describe the sociodemographic and epidemiological characteristics and healthcare utilization patterns-primary healthcare (PHC) use, emergency department (ED) visits, and hospital admissions-of children under 5 years of age born in Portugal between July 1, 2010, and June 30, 2021, and diagnosed with TB during the same period. METHODS: This is a quantitative, observational cohort study of 58 children diagnosed with TB and reported to the National Epidemiological Surveillance System (SINAVE) before age 5. Data were obtained through linkage of five population-based databases. Descriptive statistics and bivariate analyses were conducted. Incidence rates of PHC, ED visits, and hospital admissions were calculated per 1000 person-days. RESULTS: Most TB cases (81.0%) were diagnosed between ages 1 and 5; 55.2% were male, and 72.2% resided in metropolitan areas. Over half (58.6%) were unvaccinated with BCG. Unvaccinated children were diagnosed earlier than vaccinated peers (p < 0.01), though no significant differences were found in the clinical presentation of TB, risk factors, or healthcare utilization. Pulmonary TB was most common (51.7%), and 68.4% of children were hospitalized. PHC services were underutilized (32.7%), while ED visits were more frequent, primarily for infectious and respiratory conditions. One child died, with TB diagnosed post-mortem. CONCLUSIONS: TB in young children remains a public health concern in Portugal, especially in unvaccinated populations. Strengthening PHC access and preventive care is essential to improve early detection and outcomes. WHAT IS KNOWN: • TB causes substantial morbidity and mortality, particularly in children under 5 years of age. • Pediatric TB remains underdiagnosed and underrepresented in research, surveillance, and national policies. WHAT IS NEW: • BCG vaccination was associated with later onset of TB. • Children under five with TB represent a particularly vulnerable group; thus, it is critical to promote preventive care to ensure early diagnosis and effective follow-up.