Case Study

Nigeria – CAD4TB to Reduce False Negatives from GeneXpert test

Radiographer is looking into CAD4TB platform to check the result

The WoW truck, equipped with advanced TB diagnostic tools, focused on high CAD4TB scores to identify TB cases, even when Xpert tests were negative. This approach led to the clinical diagnosis of TB in a significant number of patients, highlighting CAD4TB’s role in reducing false negatives and enhancing TB detection and treatment outcomes.

WoW truck for community-based TB diagnosis

The OneStopTB Mobile Clinic (WoW truck) was equipped with EasyDR digital X-ray, CAD4TB, and GeneXpert to support community-based TB diagnosis.

Screening strategy: focus on high CAD4TB scores

The screening strategy prioritized individuals with high CAD4TB scores (≥80), even when GeneXpert results were negative.

Clinical review of Xpert-negative cases

Chest X-rays with high CAD4TB scores were further evaluated by radiologists and clinicians to assess the likelihood of active TB.

Treatment initiation based on clinical diagnosis

Individuals clinically diagnosed with TB were promptly started on TB drug treatment.

Result

Between August 2020 – March 2021,

4 85 symptomatic individuals
were Xpert-negative but had CAD4TB scores ≥80
3 07 (63%)
were clinically diagnosed with TB
60 % of WoW truck TB diagnoses
were identified through this approach
100 %
showed symptom reduction after treatment
Chest X-ray image in CAD4TB of a child in Nigeria
Conclusion
  • CAD4TB supported the identification of TB cases that were missed by bacteriological testing alone.
  • Focusing on high CAD4TB scores reduced false negatives from Xpert testing.
  • Integrating CAD4TB with clinical and radiological review improved TB detection and treatment outcomes in community-based screening.

REFERENCE: “The 52nd UNION conference “Using Artificial Intelligence to Improve diagnosis of TB on the Wellness on Wheels (Wow): Streamlining Clinical diagnosis with the use of CAD4TB Scores”, Tukur et al,, KNCV Nigeria