Comparative Yield of Tuberculosis during Active Case Finding Using GeneXpert or Smear Microscopy for Diagnostic...

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Diagnostic Technologies

Background:

• Tuberculosis (TB) remains a significant global health challenge, necessitating effective active case finding (ACF) strategies.
• The TB REACH initiative aimed to improve TB case detection through various interventions.
• Optimizing diagnostic methods and screening approaches is crucial for enhancing TB control programs.

Purpose of the Study:

• To compare the yield of different TB ACF interventions implemented in Nepal.
• To evaluate the effectiveness of smear microscopy versus GeneXpert MTB/RIF for TB diagnosis in ACF settings.
• To assess the additional TB cases identified through ACF interventions compared to routine reporting.

Main Methods:

• The study compared three ACF interventions: door-to-door screening of social contacts, TB camps, and hospital outpatient department (OPD) screening.
• Symptomatic individuals identified were tested using either smear microscopy or GeneXpert MTB/RIF.
• Case notification rates in intervention districts were compared with control districts using standard TB REACH methodology.

Main Results:

• A total of 1092 TB cases were identified, with hospital OPD screening yielding the highest proportion (52%).
• GeneXpert MTB/RIF testing showed a significantly higher positivity rate (5.5%) compared to smear microscopy (2%).
• ACF interventions achieved 29% additional case notifications in intervention districts, highlighting the impact of enhanced strategies.

Conclusions:

• Hospital OPD screening combined with GeneXpert MTB/RIF testing is a highly effective strategy for TB case finding.
• Scaling up community-based ACF for TB patient contacts and integrating GeneXpert in district hospitals can substantially increase national TB case notifications in Nepal.
• These findings provide evidence for optimizing national TB control programs through targeted interventions and advanced diagnostics.