Guideline: Management of Drug-Resistant Tuberculosis » Case Finding Strategies



4.1. Risk Groups for MDR-TB


Intensified case finding should be conducted among patients at high risk of MDR-TB based on the history. Specific elements of the history that suggest an increased risk for drug resistance are listed in the table below.


4.2. Intensified Case Finding for MDR-TB


Routine culture and first-line DST should be done for the following groups of patients:

  • New TB patients who remain sputum smear-positive after two months of treatment or who become positive after five months of treatment.
  • All newly diagnosed re-treatment TB patients.
  • Symptomatic close contacts of confirmed MDR- and XDR-TB patients.
  • Symptomatic individuals from known high-risk groups, including HCWs, laboratory workers, prisoners, mine workers and HIV-positive individuals in high MDR-TB prevalence areas.

First-line DST should include testing for isoniazid and rifampicin mainly; ethambutol and streptomycin should not be included routinely as this does not change the management of MDR- TB patient.

Previously treated TB (retreatment) patients may have had DST results in the past that may no longer reflect the resistant pattern of the strain they have at the time of MDR-TB diagnosis.  DST should therefore be performed again in all patients who have received TB treatment since the date of their last DST result.

Young children may not be able to produce sputum specimens, therefore other measures such as gastric aspiration and/or induced sputum should be considered to obtain a specimen for confirmation of diagnosis. Children with TB disease who are close contacts of patients with MDR- TB may be started on MDR-TB treatment until it is confirmed that they do not have MDR-TB.


4.3. Intensified Case Finding Strategies for XDR-TB


All strains identified as MDR-TB should routinely undergo second-line DST in order to diagnose or rule out XDR-TB. In specific instances, (i.e. when  screening contacts of known XDR-TB patients), second-line DST should be requested together with first-line DST. The tests that should be conducted routinely are kanamycin, ofloxacin, capreomycin, moxifloxacin and ethionamide. Other tests may be conducted on request by the treating clinician.