Resistance to anti-tuberculosis drugs and practices in drug susceptibility testing in Moldova, 1995-1999

To evaluate practices in initial drug susceptibility testing (DST) in Moldova, anti-tuberculosis drug resistance and the implications for tuberculosis control.

Retrospective record review in the national reference laboratory.

Of 3463 cases, 57.1% were recorded as 'new' and 24.6% as 'retreatment' cases; previous treatment status was not recorded for 18.3%. Of the 'new' cases, 1655 were correctly classified according to international recommendations and 322 were misclassified. The number of cases increased from 443 in 1995 to 939 in 1999; the proportion of 'retreatment' increased from 17.4% to 35.5%, 'any drug resistance' from 20.3% to 41.6%, and 'multidrug resistance' from 2.7% to 11.2%. In 1998-1999, 'any drug resistance' and 'multidrug resistance' in 800 previously untreated cases were respectively 29.1% and 5.3%, and respectively 61.0% and 21.9% in 521 'retreatment' cases. Of a total of 216 'multidrug-resistant' cases in 1998-1999, 21.8% were reported resistant to ethambutol and 81.5% to streptomycin.

Initial specimens for culture are frequently taken late, after the start of treatment, compromising their usefulness for case management or surveillance. Inadequate treatment has led to an increase in the number of cases, the proportion of previously treated cases and the prevalence of drug resistance. In 1998-1999, a high proportion of cases with 'multidrug resistance' were susceptible to ethambutol.