Most US Adults With MDR-TB Are Not Eligible for WHO’s Treatment Recommendations

In 2016, the World Health Organization (WHO) recommended a shorter multidrug-resistant tuberculosis (MDR-TB) treatment regimen. However, a new analysis shows that few of the US patients who had had MDR-TB during 2011-2016 would have been eligible to follow the 9- to 12-month treatment regimen.

In fact, of the 586 cases of MDR-TB that had been reported during 2011-2016 to the US National TB Surveillance System, only 10% were eligible for the shorter regimen.

The WHO recommendation to lower the conventional 18- to 24-month MDR-TB treatment regimen to a shorter 9- to 12-month regimen was indicated for patients without extrapulmonary TB; pregnancy; a previous second-line TB medication exposure; or drug resistance to pyrazinamide, ethambutol, kanamycin, moxifloxacin, ethionamide, or clofazimine.

The researchers assessed eligibility for the shorter regimen among US MDR-TB cases that had full drug susceptibility testing (DST) results and that were reported to the US National TB Surveillance System from 2011 to 2016.

Only 59 of the 586 cases were eligible for the shorter regimen. Of the 527 ineligible patients, 386 had full DST, of which 246 were resistant to ethambutol and 217 were resistant to pyrazinamide.

In terms of cost burden, eligible individuals would benefit more than society as a whole. Compared with conventional MDR-TB treatment, implementing the shorter regimen would have reduced the US annual societal MDR-TB cost burden by 4% and the eligible individuals’ cost burden by 37% to 46%.

—Colleen Murphy

Reference:

Tsang CA, Shah N, Armstrong LR, Marks SM. Eligibility for a shorter treatment regimen for multidrug-resistant tuberculosis in the United States, 2011–2016. Clin Infect Dis. 2020;70(5):907-916. https://doi.org/10.1093/cid/ciz263.