Outcomes and Diagnostic Processes in Outpatients with Presumptive Tuberculosis in Zomba District, Malawi

In Malawi, outpatients who have presumptive tuberculosis (TB), i.e. fever, night sweats, weight loss and/or any-duration cough (HIV-infected) or cough of at least 2 weeks (HIV-uninfected), are registered in chronic cough registers. They should receive a diagnostic work-up with first-step provider-initiated HIV testing and sputum testing which includes XpertMTB/RIF, following a national algorithm introduced in 2012.

An operational study, in which we prospectively studied 6-month outcomes of adult outpatients who were registered in chronic cough registers in Zomba Central Hospital and Matawale peri-urban Health Center, between February and September 2013. We recorded implementation of the diagnostic protocol and outcomes at 6 months from registration.

Of 348 patients enrolled, 165(47%) were male, median age was 40 years, 72(21%) had previous TB. At registration 154(44%) were known HIV-positive, 34(10%) HIV-negative (26 unconfirmed) and 160(46%) had unknown HIV status; 104(56%) patients with unknown/unconfirmed HIV status underwent HIV testing. At 6 months 191(55%) were HIV-positive, 87(25%) HIV-negative (26 unconfirmed) and 70(20%) still had unknown HIV status. Higher age and registration in Matawale were independently associated with remaining unknown HIV status after 6 months. 62% of patients had sputum tested, including XpertMTB/RIF, according to the algorithm. TB was diagnosed in 54(15%) patients. This was based on XpertMTB/RIF results in 8(15%) diagnosed cases. In 26(48%) TB was diagnosed on clinical grounds. Coverage of ART in HIV-positive patients was 89%. At 6 months, 236(68%) were asymptomatic, 48(14%) symptomatic, 25(7%) had been lost-to-follow-up and 39(11%) had died. Mortality among those HIV-positive, HIV-negative and with unknown HIV-status was 15%, 2% and 10%, respectively. Male gender, being HIV-positive-not-on-ART and not receiving antibiotics were independent risk factors for mortality.

HIV prevalence among patients with presumptive TB was high (55%). One quarter was not HIV tested and mortality in this group was substantial (10%). The impact of XpertMTB/RIF on TB diagnosis was limited.