Researchers have evaluated World Health Organization data on tuberculosis (TB) from 2003 and 2004 to find that patients in countries with high rates of multidrug resistant TB (MDR-TB) are twice as likely to fail their initial treatment. The evaluation’s findings suggest that current TB treatment needs to be updated and revised, according to the researchers.

“In countries with low prevalence of initial multi-drug resistance, the standardized treatment regimens for new cases appear to be adequate,” says lead author Dick Menzies MD, from McGill University. “However, in countries where the prevalence of initial drug resistance exceeds 3%, we believe it is urgent to strengthen capacity to perform drug sensitivity testing, or to reevaluate these standard treatment regimens, given the unacceptably high rates of failure and relapse.”

The data included a total of 155 countries, 121 of which reported at least 250 cases of MDR-TB annually. Dropout, failure, relapse, and death rates with initial treatment and retreatment were assessed.

In countries with a low prevalence of MDR-TB, 11.9% of patients required retreatment. This percentage nearly doubled in countries with high prevalence of MDR-TB to 21.4% of patients requiring retreatment.

The study was published in the first August edition of the American Journal of Respiratoryand Critical Care Medicine.