Assessing tuberculosis clinical presentation, diagnosis and treatment outcomes among children under 5 years old: results from a cohort of children with presumptive TB in Cameroon and Kenya.

Introduction: The majority of paediatric tuberculosis (TB) cases remain undiagnosed or unreported, with only 55% of the estimated 1.25 million paediatric TB cases reported in 2023. We leveraged the INPUT study to characterise the clinical presentations and factors associated with TB diagnosis and treatment success in children under 5 years in Cameroon and Kenya. Method: We conducted a prospective cohort analysis nested in the INPUT study, implemented from May 2019 to June 2021 to assess the integration of paediatric TB services into child healthcare services. All children presenting in participating health facilities, presumed with TB and eligible to the INPUT study, were enrolled and followed up from diagnosis to treatment initiation and completion. We used multivariable logistic regression to explore factors associated with TB diagnosis. Results: Of the 790 children enrolled in the cohort, 458 (58.0%) were aged <2 years; the most frequent suggestive TB symptoms were cough (76.5%), fever (34.9%), night sweats (21.2%), loss of appetite (33.5%) and fatigue (35.9%). Overall, 157 (19.9%) children were diagnosed with TB disease, including 13/157 (8.3%) bacteriologically confirmed and 84/157 (53.5%) with a chest radiography evocative of TB. In multivariable analysis, living in rural area (aOR 1.9; 95% CI (1.1 to 3.5)), presenting with fever >10 days (aOR 1.8; 95% CI (1.1 to 3.1)), having HIV (aOR 3.9; 95% CI (1.7 to 8.9)), presenting with acute malnutrition (aOR 2.8; 95% CI (1.5 to 5.2)), living with someone coughing in the household for more than 2 weeks (aOR 1.8; 95% CI (1.0 to 3.0)) and presenting with peripheral lymphadenitis (aOR 9.5; 95% CI (4.3 to 20.9)) were significantly associated with TB diagnosis in children under 5 years with signs and symptoms suggestive of TB. All children diagnosed with TB were initiated on treatment; 136 (86.6%) achieved treatment success according to WHO definition. Conclusion: In the context of integrated, decentralised evaluation of paediatric TB in the INPUT study, most TB diagnoses in children under 5 years old were made clinically-radiologically. Decentralised strategies enhancing the clinical diagnosis, including repeated capacitation of clinicians to the use of treatment decision algorithms and increased access to chest radiography, could overcome underdiagnosis of paediatric TB. Trial registration number: NCT03862261.