High mortality rates in tuberculosis patients in Zomba Hospital, Malawi, during 32 months of follow-up

There is little information about long-term follow-up in patients with smear-negative pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB) who have been treated under routine programme conditions in sub-Saharan Africa. A prospective study was carried out to determine outcome 32 months from start of treatment in an unselected cohort of 827 adult TB inpatients registered at Zomba Hospital, Malawi, in 1 July-31 December 1995. By 32 months, 351 (42%) patients had died. Death rates were 30% (95% confidence interval [95% CI] 25-35%) in 386 patients with smear-positive PTB, 60% (95% CI 53-67%) in 211 patients with smear-negative PTB and 47% (95% CI 40-54%) in 230 patients with EPTB. Of the 793 patients with concordant HIV test results 612 (77%) were HIV seropositive: 47% HIV-positive patients were dead by 32 months compared with 27% HIV-negative patients (adjusted hazard ratio [HR] 2.3; 95% CI 1.7-3.1, P < 0.001). Smear-negative PTB patients had the highest death rates during the 32-month follow-up (HR 2.7; 95% CI 2.1-3.5, P < 0.001 compared to smear-positive patients), followed by EPTB patients (HR 1.9; 95% CI 1.5-2.5, P < 0.001 compared to smear-positive patients). When analysis was restricted to after the treatment period had finished (i.e., months 12-32), the differences in mortality were maintained for HIV-serostatus and for types of TB. Low-cost, easy to implement strategies for reducing mortality in HIV-positive TB patients in sub-Saharan Africa (such as the use of trimethoprim-sulphamethoxazole prophylaxis) need to be tested urgently in programme settings.