DRUG RESISTANT TB

Drug resistance is said to occur when TB organisms continue to grow in the presence of one or more anti-TB
medicines.

  • Although several factors can contribute to the development of drug-resistant TB, inadequate anti-TB
    treatment is probably the most important. Inadequate anti-TB treatment leads to mutation in drug-susceptibility
    bacilli making them drug resistant.

Risk factors for drug-resistant TB are:

  • Chronic cases (still sputum smear-positive after completing a supervised retreatment regimen)
  • Contact with known drug-resistant tuberculosis
  • Retreatments (relapses, treatment after failures, return after loss to follow-up)
  • History of frequent interruption of drug treatment
  • HIV-positive patient presumed to have TB
  • Patients who remain sputum smear-positive at month 2 or 3 of first-line anti-TB treatment
  • Health care workers
  • Patients from prisons or other congregate settings

Patients suspected to have DR-TB should be screened using rapid drug susceptibility testing (DST) of rifampicin
(Xpert MTB/RIF)

  • All patients who are drug-resistant TB suspects should therefore have sputum/other specimens taken for culture
    and DST in vivo.

Patients with drug-resistant TB should be treated at specialised centers with approved regimens.

DRUG RESISTANT TB IS A MAJOR PUBLIC HEALTH PROBLEM. INADEQUATE TB TREATMENT IS THE
MAJOR CONTRIBUTING FACTOR!