Tuberculosis Drug Resistance and Outcomes among Tuberculosis Inpatients in Lilongwe, Malawi

Setting/Objective: We evaluated clinical characteristics, yield of solid vs. liquid culture, polymerase chain reaction (PCR)-based drug-resistance profiles, and clinical outcomes of tuberculosis (TB) inpatients in Lilongwe, Malawi.
Design: We enrolled adult patients admitted to the Bwaila TB Ward from Jan-Aug/2010. Evaluations included questionnaires, clinical exam, chest radiograph, HIV status, CD4 lymphocyte count, plasma HIVRNA and sputum analysis including Auramine-O stain, Lowenstein-Jensen (LJ) and Mycobacterial Growth Indicator Tube (MGIT) culture, and susceptibility testing using the HAIN GenoType® MTBDRplus.
Results: Eighty-eight patients were enrolled (88% re-treatment, 42% smear positive, 93% pulmonary TB, 74% HIV co-infected). At baseline, 44/88 (50%) MGIT and 28 (32%) LJ cultures were positive with a mean time to positivity of 12.1 (Range 1-42) and 21.5 (Range 7-58) days, respectively. Four percent (3/77) of retreatment patients or 8% of the 38 MGIT+ PCR-confirmed retreatment cases had multi-drug resistant tuberculosis (MDR TB). One MDR TB patient was smear negative and only one MDR patient was identified with LJ. Lower mean hemoglobin at admission was associated with mortality (10.5 vs. 7.5; p<0.01; CI 101 9.8-11.0).
Conclusions: The MDR TB burden among the retreatment population in Lilongwe, Malawi is similar to regional estimates by the WHO (7.7% 95% CI 0-18.1). MDR TB patients are not routinely identified with sputum smear or LJ, suggesting more efficient technology should be adopted.