Case Study

Malawi – Improving TB Case-finding in Key Populations with OneStopTB Clinic

TB screening in Malawi

Key populations such as refugees, internally displaced persons, miners, inmates, and healthcare workers face elevated TB risk and limited access to diagnostic services. Malawi implemented targeted mobile TB screening to improve detection in these groups.

Targeted outreach screening

Mobile Diagnostic Units were deployed to conduct TB screening in 28 districts.

Focus on key populations

Screening targeted inmates, healthcare workers, miners and ex-miners, communities, IDPs, and refugees.

Digital X-ray with AI

Digital chest X-ray with CAD4TB was used alongside symptom screening.

Molecular confirmation

Presumptive TB cases with CAD4TB scores above 60 were evaluated using GeneXpert.

Result

In 2022 screening period,

30 ,225 people
were screened using symptoms and digital CXR with CAD
1 ,993 people
were identified as presumptive TB
93 % of presumptive cases
underwent Xpert testing
  • 165 were diagnosed with TB, representing 546 cases per 100k individuals screened, which is four times higher than the TB incidence in the general population (132/100k).
  • The highest yield among screened was refugees (957/100k), followed by IDPs (567/100K), miners (535/100K), inmates (523/100k), and HCWs (510/100k).
  • The highest yield among presumptive was refugees (23%), followed by miners (18%), IDPs (10%), HCWs (8%) and inmates (7%). 97.6% of the cases were enrolled to TB treatment.
  • Further analysis found that 20% of presumptive cases were identified only by chest X-ray (no symptom), which aligns with the findings of the National TB Prevalence Survey. 80% of presumptive cases had symptoms, and 47% had abnormal chest X-rays.
TB screening in Malawi
Conclusion
  • The findings highlight the need for targeted TB screening and diagnostic strategies for each risk group.
  • The parallel CXR and symptom screening approach has proven effective and provides valuable insights that can help scale up more effective TB case-finding.

REFERENCE: Gondol, B. S. (2023, November 15-18). Parallel chest X-ray and symptom screening for TB among marginalised and key populations in Malawi: an effective TB screening and diagnostic strategy [Conference session]. The Union World Conference on Lung Health 2023, Paris, France.