Prevalence and clinical predictors of drug-resistant tuberculosis in three clinical settings in Calabar, Nigeria

Abstract

Background and aims: Drug-resistant tuberculosis (TB) poses a serious challenge to global control of TB. This multicentre study was to identify risk factors for drug resistance to the first line anti-TB drugs among TB patients presenting for care in three health facilities in Calabar, Nigeria.

Materials and methods: A cohort of 100 consecutive TB patients were recruited. Demographic information such as age, sex, weight, height, occupation, previous TB diagnosis and treatment, smoking, alcohol dependence and substance abuse were obtained. Sputum samples were collected from participants and cultured on Lowenstein - Jensen (LJ) slopes. Drug susceptibility testing was then carried out for the isolates identified as Mycobacterium tuberculosis, using isoniazid, rifampicin, ethambutol and streptomycin.

Results: Forty-two of the 100 participants evaluated were found to be resistant to at least one drug. Multi-drug-resistant TB was seen in four persons. Statistically significant differences were found with respect to three variables: younger age, abandonment of TB treatment and presence of cavitary lesions on chest radiograph. The variables sex, alcohol dependence, tobacco use and previous imprisonment were not significantly associated with TB drug resistance. Four variables were significant following the multivariate analysis with the following adjusted odds ratios: abandonment of TB treatment (9.34), cavitary lesions on chest radiograph (5.88), younger age (6.25) and male sex (3.25).

Conclusion: Thus, risk stratification of TB patients is advocated in clinical settings where diagnostic facilities for drug-resistant TB are scarce using the identified predictors. This group will benefit from close monitoring and early drug susceptibility testing.

Keywords: Nigeria; correlates; drug resistance; tuberculosis.