Background: Tuberculosis (TB) is the most common cause of death in HIV-positive patients. Early detection and anti-TB treatment initiation improves outcomes and minimizes ongoing transmission. Intensified case finding (TB-ICF) among HIV-positive patients is recommended by the WHO, however evidence from routine implementation at high-volume antiretroviral therapy (ART) clinics in resource-constrained settings is scarce. Here, we describe the yield of TB-ICF conducted by community health workers (CHWs) among HIV-positive patients accessing ART in rural Malawi.
Methods: Thirteen CHWs employed by the Baylor Tingathe outreach program were trained to conduct TB-ICF using a standardized symptom screening tool at a large rural district hospital. Patients were screened while awaiting routine services at ART clinic. Patients screening positive were triaged for assessment by a clinician and sputum analysis by smear microscopy and GeneXpert. Patients were followed up until final diagnosis and traced if necessary. Sixteen months of pre- and six months of post-intervention data was abstracted from registers and tools used by CHWs. Single-group interrupted time series analysis was used to assess impact of the intervention.
Results: The mean number of monthly TB diagnoses made at ART clinic increased by a factor of 20 post-intervention(0.5 vs 10.0 monthly diagnoses, p< 0.0001). In the first month of the intervention an immediate increase of 6.7 monthly diagnoses occurred (p< 0.0001, Figure 1). There was a statistically significant increase in the monthly trend of TB diagnoses relative to the pre-intervention trend of 0.78 per month(p=0.026). The yield of screening in the post-intervention period was 10.0%(46/459). Diagnoses were only made in children post-intervention(9/46, 19.6%).

Figure 1. Actual and model-fitted monthly TB diagnoses at ART clinic before and after CHW TB-ICF
[Figure 1. Actual and model-fitted monthly TB diagnoses at ART clinic before and after CHW TB-ICF]

Conclusions: Implementation of TB-ICF with CHWs was associated with significant increases in the number and trend of monthly TB diagnoses. Screening resulted in favorable yields, and helped link children to care. Future work is needed to ascertain the durability of this effect and the impact on treatment outcomes.