Time to sputum culture conversion of Multidrug-Resistant tuberculosis in HIV positive versus HIV negative patients in Lesotho

Abstract

Background: Multi-Drug resistant tuberculosis (MDR-TB, resistance to at least Isoniazid and rifampicin) is a disease of public health importance, accounting for an estimated 490,000 new cases globally in 2016. Historically, cure rates in MDR-TB/HIV co-infected patients were lower than in HIV negative patients, partly due to high morbidity and mortality associated with retro-viral disease. Lesotho has one of the highest levels of tuberculosis and probably multidrug-resistant TB in the world. However, efforts to control this disease including the introduction of the World Health Organization (WHO)-recommended DOTS-Plus and recently endTB strategies for multi-drug resistant TB contributed significantly to the decline of the disease. Aim: This study evaluated the association between HIV and time to sputum culture conversion in MDR-TB patients who were on the MDR-TB regimen and Antiretroviral treatment (if HIV positive), between January 2011 and December 2016. Method: The study used a retrospective cohort study design of consecutive patients who were initiated on MDR-TB regimen from January 2011 to June 2016 in Lesotho. All patients were followed up until death, loss to follow-up, sputum conversion or censored at the end of December 2016, whichever came first. Results: A total of 346 patients with confirmed MDR-TB records were included in the study. Of these, 58.02% (n=199) were male, a third of the patients were married (n= 122 [35.67%]) and about four fifths (n=277 [81.15%]) were HIV positive. The HIV positive patients achieved sputum culture clearance at a median of 54.22 (IQR 22-117) days, while the HIV negative patients achieved conversion at 60.84 (IQR 24-129) days. There was no statistically significant difference in the sputum culture conversion rates by HIV status (AHR: 1.11, CI: 0.82-1.50, p-value: 0.486). Residing in rural area (AHR: 1.60 CI: 1.20-2.14, P-value: 0.001) and good adherence (AHR: 15.84 CI: 2.21-113.60, P-value: 0.006) independently predicted higher sputum culture clearance rates. Conclusion: HIV-status does not affect sputum culture conversion in MDR-TB patients on ART in Lesotho.