Stool-based Xpert test on childhood tuberculosis diagnosis in Nigeria

Who

• Population: Children aged 0–14 years presumed to have tuberculosis (TB).

• Sample size: 52,117 children who submitted stool specimens and 391,217 children who submitted sputum specimens.

• Setting: 1082 health facilities (11 tertiary, 126 secondary, 945 primary).

• Key demographics:

  • Stool testing: 59.7% aged 0–4 years; 40.3% aged 5–14 years

  • Higher referral and diagnosis among males, especially in the 0–4 age group

  • Drug-resistant TB (DR-TB) proportion higher in the 5–14 age group

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What

• Focus: Evaluation of the impact of stool-based Xpert MTB/RIF testing on childhood TB diagnosis.

• Key findings:

  • Stool-based Xpert testing diagnosed 4.8% of evaluated stool samples with TB.

  • Approximately 1.1% of stool-diagnosed TB cases were drug-resistant.

  • 94.6% of stool-diagnosed TB cases were initiated on treatment.

  • Stool testing contributed up to 17% of all bacteriologically confirmed childhood TB cases in 2022–2023.

• Conclusion: Decentralized stool-based Xpert testing significantly improved childhood TB detection and notification, particularly among younger children and at lower healthcare levels.

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When

• Implementation period:

  • Method modification and verification: Q3 2020

  • Nationwide implementation: Q4 2020 onward

  • Major awareness scale-up: Q3 2022

• Trend observation: Increased TB detection over time, except during the 2020 COVID-19 period.

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Where

• Country: Nigeria

• Geographic coverage: 14 states (Anambra, Imo, Delta, Akwa Ibom, Rivers, Cross River, Nasarawa, Benue, Plateau, Taraba, Kano, Kaduna, Katsina, Bauchi).

• Program context: States supported by the USAID-funded TB Local Organization Network (LON) 1 & 2 project implemented by KNCV Nigeria.

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Why

• Childhood TB in Nigeria has historically low bacteriological confirmation rates due to difficulty obtaining sputum samples from children.

• A 2020 national stakeholder meeting identified the need to decentralize stool-based testing to peripheral health facilities where most children seek care.

• The goal was to improve access, reduce diagnostic delays, lower costs, and increase TB case notification among children.

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How

• Study design: Cross-sectional analysis of secondary programmatic data.

• Eligibility: Children <15 years with TB symptoms who could not produce sputum were offered stool testing.

• Laboratory method:

  • Modified one-step stool-based Xpert MTB/RIF Ultra method

  • Hard-formed stool emulsified with saline, incubated, treated with sample reagent, filtered, and processed on GeneXpert

• Implementation strategies:

  • Revision of national TB guidelines and laboratory SOPs

  • Nationwide webinars and training of laboratory staff

  • Dissemination of instructional YouTube videos

  • Continuous awareness creation and capacity building

• Outcome definition: TB diagnosis based on positive GeneXpert results; both bacteriologically confirmed and clinically diagnosed cases were treated.

Source: Nwokoye, N., Odume, B., Nwadike, P., Anaedobe, I., Mangoro, Z., Umoren, M., Ogbudebe, C., Chukwuogo, O., Useni, S., Nongo, D. and Eneogu, R., 2024. Impact of the stool-based Xpert test on childhood tuberculosis diagnosis in selected states in Nigeria. Tropical Medicine and Infectious Disease, 9(5), p.100.