Policy to practice: impact of GeneXpert MTB/RIF implementation on the TB spectrum of care in Lilongwe, Malawi

Abstract

Background: While previous research has provided evidence of the diagnostic accuracy of the GeneXpert MTB/RIF (GeneXpert), further information is needed about implementation in the real-world. This study evaluated the impact of the introduction of GeneXpert testing in a tertiary medical center according to the testing algorithm proposed by the National TB Control Program (NTP) guidelines.

Methods: All adult medicine inpatient persons with presumptive TB admitted between November 2013 and March 2014 were eligible for GeneXpert sputum testing and followed to TB treatment initiation status.

Results: We identified 932 persons with presumptive TB, of which 307 (32.9%) were GeneXpert tested. Those tested had an average age of 40 years, 49.2% (151) were male, 34.5% (106) were HIV positive, and 84.1% (249) presented with a cough. Of those GeneXpert tested, 28/307 (9.1%) tested positive, a 55.5% increase in detection compared to smear microscopy. However, the majority (44/72, 61%) of TB diagnoses were made by other modalities and not confirmed microbiologically. Of the 58 patients recommended to start treatment and discharged from the hospital, only 23 (40%) were documented to have started treatment at regional directly observed treatment short (DOTS) centers.

Conclusions: GeneXpert contributed minimally to overall TB diagnosis and the cascade of care due to implementation challenges of sputum collection, empiric treatment, and weak linkage to care between inpatient and outpatient settings.

Keywords: Diagnosis; GeneXpert; GeneXpert negative TB; HIV; Malawi; Pulmonary tuberculosis.