OBJECTIVES: To determine the prevalence of resistance
to the four major anti-tuberculosis drugs, isoniazid,
rifampicin, streptomycin and ethambutol, in Yemen.
METHODS: Cluster sampling with probability proportionate
to size was applied. Susceptibility to four major
anti-tuberculosis drugs was examined. The proportion
method using Löwenstein-Jensen medium or Ogawa
medium was carried out.
RESULTS: A total of 790 primary culture isolates from
tuberculosis (TB) cases enrolled at the National Tuberculosis
Institute, Yemen, were examined. In the confirmation
culture at the supranational reference laboratory,
227 of them failed to grow on the secondary
culture or were proved to be mycobacteria other than
Mycobacterium tuberculosis and were excluded from
further analysis. Among 563 cultures, 510 were obtained
from new cases and 53 from previously treated
cases. The prevalence of resistance to any four drugs was
9.8% (95%CI 7.0–12.5) among new cases and 17.4%
(95%CI 12.0–33.5) among previously treated cases.
The prevalence of multidrug-resistant TB was 3.0%
(95%CI 1.5–4.5) among new cases and 9.4% (95%CI
0.2–18.7) among previously treated cases.
CONCLUSION: The first nationwide prevalence survey
on resistance to the four major anti-tuberculosis drugs in
Yemen showed a relatively low prevalence of drug-resistant
cases, but a high prevalence of multidrug resistance among
new cases.