Philippines – Active TB Case-finding with CAD4TB
In the Philippines, symptom-based screening alone misses many TB cases, while access to radiologists remains limited. Digital chest X-ray with CAD4TB was used to improve TB detection in the general population.
Population-based TB screening
Individuals aged 15 years and above were screened using digital chest X-ray with CAD4TB version 7.
AI- and symptom-based triage
People with CAD4TB scores of ≥28 or positive symptom screening were identified as presumptive TB cases.
Molecular testing and clinical assessment
Presumptive TB cases provided sputum for GeneXpert testing, and CXR-suggestive cases were assessed by physicians.
Treatment referral pathway
Bacteriologically and clinically diagnosed TB cases were referred to local health centers for treatment.
From October 2022 to February 2023,
- 99 (63.5%) BCTB patients were symptom screen negative.
- Among 156 Xpert results, 51 (32.7%) were trace results. 4% (47/1100) were CDTB.
- 54% (109/203) of all cases (BCTB and CDTB) initiated TB treatment.
- Higher rates of treatment initiation were observed among people with BCTB with non-trace Xpert results (81/105, 77%) compared to people with CDTB (28/47, 59%).
- Reasons for non-initiation of TB treatment include uncontactable (30/94, 32%), pending health centre initiation (35/94, 37%), repeat test needed (25/94, 27%), refusal to accept the diagnosis (4/94,4%).
- TB active case-finding using CAD4TB has identified high rates of TB, and it is a promising approach.
- Most people with BCTB reported no symptoms.
- In this setting, trace Xpert results were common, adding a challenge to TB evaluation and treatment.
- Barriers to treatment initiation require further exploration and action.
REFERENCE: Carnimeo, V. (2023, November 15-18). High-yield active case-finding with computer-aided detection does not always translate into high linkage to care [Conference session]. The Union World Conference on Lung Health 2023, Paris, France.