Risk factors associated with multidrug resistant tuberculosis among patients referred to Kibong’oto Infectious Disease Hospital in northern Tanzania

Abstract

Background: Multidrug resistant tuberculosis (MDR-TB) remains is an important public health problem in developing world. We conducted this study to determine risk factors associated with MDR-TB and drug susceptibility pattern to second line drug among MDR TB patients in Tanzania.

Methods: Unmatched case control study was conducted at Kibong’oto Infectious Diseases Hospital in Tanzania in 2014. A case was defined as any patient whose sputum yielded Mycobacterium tuberculosis that were resistance to at least rifampin (RFP) and isoniazid (INH) whereas control was defined as those sensitive to rifampin (RFP) + isoniazid (INH).  One morning sputum sample was collected from each study subject and cultured on Löwenstein-Jensen (LJ) media for M. tuberculosis. Drug susceptibility testing of isolated M. tuberculosis was done for rifampicin, isoniazid, kanamycin and ofloxacin. A semi-structured questionnaire was used to collect socio-demographic and risk factors information for MDR-TB.

Results: A total of 102 cases and 102 controls were enrolled. The predominant age group was 31- 40 years, of whom cases and controls accounted for 38 (37.3%) and 35 (34.3%) of the study subjects, respectively. Majority of participants (69% cases and 71% control) were males and self-employed (62.7% cases and 84.4% controls). More than half (52%) and approximately a quarter (24.5%) of cases and control had HIV infection, respectively. About two-thirds of cases (62.7%) were cigarette smokers compared to controls (42.2%). Previous history of TB treatment accounted for approximately three folds in cases (72.5%) and only 24.5% in controls. Risk factors independently associated with MDR-TB were previous history of treatment with first line anti-TB (OR= 3.3, 95% CI 1.7-6.3), smoking (OR=1.9, 95% CI 1.0-3.5), contact with TB case (OR=2.7, 95% CI 1.4-5.1) and history of TB. All MDR TB isolates were sensitive to kanamycin and ofloxacin.

Conclusion: MDR-TB among patients referred to Kibong’oto Infectious Diseases Hospital is associated with previous history of TB contact, smoking habit, and contact with TB case. All MDR TB isolates were sensitive to the tested second line drugs, Kanamycin and Ofloxacin.