Risk factors for multidrug-resistant tuberculosis in urban Pakistan: A multicenter case-control study

To evaluate risk factors for multidrug-resistant tuberculosis (MDR-TB) in an urban setting of Pakistan.

In this multicenter case-control study, patients aged 15years old or older with sputum culture and sensitivity (C/S) diagnosed with pulmonary MDR-TB were defined as cases, whereas patients aged 15years old or older with sputum C/S diagnosed and susceptible to pulmonary TB were regarded as controls. Fifty cases and 75 controls were enrolled from three tertiary-care hospitals in Karachi.

Multivariable logistic regression models showed that cases were more likely to have had a TB patient in the house prior to the diagnosis of MDR-TB (adjusted odds ratio [ORadj]=3.1, 95% confidence interval [CI]: 1.2, 8.3) or had a history of prior TB treatment (ORadj=4.2, 95% CI: 1.1, 15.4). Furthermore, cases compared with controls tended to be male (ORadj=3.6, 95% CI: 1.4, 9.7), 15-25years of age (ORadj=3.7, 95% CI: 1.2, 11.3), of Sindhi ethnicity (adjusted OR=9.1, 95% CI: 1.9, 43.4) or with low educational attainment (ORadj OR=5.5, 95% CI: 1.7-17.6, for no formal schooling; ORadj=3.8, 95% CI: 1.1-14.1, 1 for 1-5 school years).

A TB patient in the house or a history of prior TB treatment was strongly associated with MDR-TB in this study. Furthermore, younger age, male gender, Sindhi ethnicity and poor educational attainment entailed a high risk for MDR-TB. Targeted educational intervention for patients and their contacts may minimize the noncompliance with prescribed TB treatment and lessen MDR-TB magnitude in settings like Karachi.