The role of bacteriological monitoring using culture and drug susceptibility tests (CDST) on treatment outcomes among MDR/RR-TB patients on treatment: a cohort analysis of patients enrolled on treatment 2010-2015 in Zimbabwe

Abstract

Introduction: an estimated 25% of the world population is infected with Mycobacterium tuberculosis. In 2017, new tuberculosis cases were estimated at 10 million, while 1.6 million tuberculosis related deaths were recorded, 25% residing in Africa. Treatment outcomes of multi drug resistant Tuberculosis patients in Zimbabwe has been well documented but the role of bacteriological monitoring on treatment outcomes has not been systematically evaluated. The objective of the study was to determine the role of bacteriological monitoring using culture and drug susceptibility tests on treatment outcomes among patients with multi drug resistant tuberculosis.

Methods: a retrospective, secondary data analysis was conducted using routinely collected data of patients with multi drug resistant TB in Zimbabwe. Frequencies were used to summarize categorical variables and a generalized linear model with a log-link function and a Poisson distribution was used to assess factors associated with unfavourable outcomes. The level of significance was set at P-Value<0.05.

Results: the study collected data from 473 records of patients with an average age of 36.35 years. Forty-nine percent (49%) were male and 51% were female. Results showed that when a patient has baseline culture result missing, has no culture conversion result, regardless of having a follow up culture and drug susceptibility test result, the risk of developing unfavourable outcomes increase by 3.9 times compared to a patient who has received all the three (3) bacteriological monitoring tests.

Conclusion: results highlights the need for consistent bacteriological monitoring of patients to avert unfavourable treatment outcomes.