Anti-tuberculosis drug resistance is a major problem in tuberculosis (TB) control, particularly
multi-drug resistance TB (MDR-TB). The objective of this study was to determine the prevalence of primary
and acquired anti-TB drug resistance among newly diagnosed pulmonary TB (PTB) and relapse cases. Sputa
were collected from newly diagnosed and relapse PTB patients. Drug susceptibility tests (DST) were
performed on sputum culture positive isolates of
Mycobacterium tuberculosis
using resistance ratio method on
four first-line anti-TB drugs: rifampicin, isoniazid, ethambutol and streptomycin. Demographic and
anthropometric information was collected and HIV status was determined. Of the 523 culture positive
isolates, DST results were available for 503 (96%), 455 were new and 48 were relapse cases. Resistance to at
least one of the four drugs was observed in 7.8% (39/503) of the isolates, 7.3% (33/455) were new and 12.5%
(6/48) were from relapse cases. Mono resistance to isoniazid was higher in both among new 45.5% (15/33)
and relapse 50.0% (3/6) cases. Resistance to rifampicin and streptomycin alone was equal 4/33 (12.1%) and
only among new cases. Resistance to ethambutol alone was only one among new cases. Overall MDR-TB
prevalence was 2.4% (12/503), nine were new and three were relapse cases. MDR-TB was 17.9% (7/39) for
rifampicin and isoniazid. Prevalence of HIV was 43.3% and was similar among new and relapse cases and
not risk factor for drug resistance. Majority of PTB patients (52%) had BMI below 18 kg/m2. Those with BMI
greater than 18 kg/m2 were more likely to develop drug resistance than those with BMI below 18 kg/m2
(P=0.004). With the resurgence of TB and the high prevalence of HIV among TB patients, prevalence of drug
resistance is still low both among new and relapses cases. Despite the current low drug resistance, there is a
need for continuous monitoring of the resistance.
