First- and second-line anti-tuberculosis drug resistance in Northwest Ethiopia.

SETTING

Gondar Hospital, Gondar Health Centre, Metemma Hospital, Bahir Dar Hospital and Debre Markos Hospital in Northwest Ethiopia.

OBJECTIVE

To assess the level of and risk factors for first- and second-line drug resistance among tuberculosis (TB) patients.

DESIGN

Drug susceptibility testing (DST) against first-line drugs, including isoniazid (INH), rifampicin (RMP), streptomycin (SM), ethambutol (EMB) and pyrazinamide (PZA), was performed using the BacT/ALERT 3D system. DST against second-line drugs, including fluoroquinolones and aminoglycocides/cyclic peptides, was performed using GenoType MTBDRsl.

RESULTS

Of 260 Mycobacterium tuberculosis isolates, 41 (15.8%) were resistant to at least one first-line drug, 13 (5.0%) were multidrug-resistant (MDR) and 9 (3.5%) were resistant to all first-line drugs. Any resistance to INH, RMP, SM, EMB and PZA was respectively 36 (13.8%), 15 (5.8%), 26 (10.0%), 19 (7.3%) and 12 (4.6%). Of 214 new and 46 previously treated cases, respectively 8 (3.7%) and 5 (10.9%) were MDR. All isolates were susceptible to all second-line drugs.

CONCLUSION

A substantial number of new and previously treated cases harbour MDR-TB. We recommend DST at least for previously treated cases, patients who remain smear-positive at the end of the second month of treatment and patients in close contact with MDR-TB cases. Improved infection control measures need to be implemented in Ethiopia.