INCIDENCE AND FACTORS ASSOCIATED WITH LATE SPUTUM CULTURE CONVERSION AMONG MULTI- DRUG-RESISTANT TUBERCULOSIS PATIENTS ON TREATMENT IN NATIONAL REFERAL HOSPITAL UGANDA

Abstract Background Tuberculosis (TB) remains one of the most common causes of death from an infectious disease. Late sputum culture conversion among Multi-Drug-Resistant Tuberculosis (MDR-TB) patients poses a risk for poor treatment outcomes. The study aimed to determine the incidence and factors associated with late sputum culture conversion among MDR-TB patients on treatment at the tuberculosis (TB) unit of Mulago National Referral Hospital. Methods A retrospective cohort study of 255 MDR-TB patient records between January 1 st 2012 to December 31 st 2018 were reviewed. Consecutive sampling was employed. Demographic characteristics, clinical factors and social factors were studied. STATA version 15 was used for analysis. Incidence was calculated as the ratio of MDR -TB patients with late sputum culture conversion result to the total number of participants studied. Factors associated were evaluated using generalized linear model (GLM) with Poisson family and log link using robust standard errors to adjust for over inflated variances. Results The incidence of late sputum culture conversion was 32% (95% CI 26.3-37.8). increasing age in years (incidence rate ratio IRR 1.004, 95%CI 1.000 1.008, P value 0.044), increasing weight (IRR 0.995, 95% CI 0.991-0.999, P value 0.020) and 9-12 months multi drug tuberculosis MDR-TB regimen (IRR 0.893, 95% CI 0.805-0.989, P value 0.030) were factors associated with late sputum culture conversion. Conclusions The incidence of late sputum culture conversion among MDR-TB patients on treatment was high (32%), occurring in about three out of every ten patients. Increasing weight, increasing age and 9-12 months MDR-TB drug regimen were significantly associated. Isolation of patients for a minimum of two months to minimize community transmission, starting eligible patients on the 9-12months MDR-TB regimen and categorization of patients into high-risk groups (elderly and underweight) with special targeted packages.