title: Identifying multidrug resistance in previously treated tuberculosis patients: a mixed-methods study in Cambodia.
abstract: METHODS
  Previously treated tuberculosis (TB) patients are a priority for drug susceptibility testing (DST) to identify cases with multidrug-resistant TB (MDR-TB). A Cambodia study found that one third of smear-positive previously treated patients had DST results.
  
  
  OBJECTIVE
  To quantify the gaps in the detection of MDR-TB in previously treated TB patients in Cambodia, and describe health workers' perspectives on barriers, facilitators and potential interventions.
  
  
  METHODS
  Analysis of Cambodia's 2004-2012 case notifications and semi-structured interviews with stakeholders.
  
  
  RESULTS
  The proportion of previously treated notifications varied significantly across provinces in 2010-2012. If there had been no attrition along the path to detecting MDR-TB among smear-positive notified cases in 2012, an estimated 75 additional MDR-TB cases could have been identified, which would double the number actually detected. Most were lost due to misclassification of previously treated patients as 'new'. Barriers include patients' reluctance to disclose and staff difficulty in eliciting treatment history, partly attributed to the availability of streptomycin (SM) only in hospitals. Facilitators include collection of sputum for DST even if previously treated patients are not receiving SM, streamlining sputum transportation and prompt reporting of results.
  
  
  CONCLUSIONS
  Improved monitoring, supportive staff supervision and training, patient education, and correct classification of previously treated cases are essential for improving the detection of MDR-TB.
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA.
authors.forename: S
authors.initials: S
authors.lastname: Royce
authors.affiliation: Cambodia Office, World Health Organization, Phnom Penh, Cambodia.
authors.forename: S
authors.initials: S
authors.lastname: Khann
authors.affiliation: Cambodia Office, World Health Organization, Phnom Penh, Cambodia.
authors.forename: R P
authors.initials: RP
authors.lastname: Yadav
authors.affiliation: National Centre for Tuberculosis and Leprosy Control, Phnom Penh, Cambodia.
authors.forename: E T
authors.initials: ET
authors.lastname: Mao
authors.affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, USA.
authors.forename: A
authors.initials: A
authors.lastname: Cattamanchi
authors.affiliation: Cambodian Health Committee, Phnom Penh, Cambodia.
authors.forename: S
authors.initials: S
authors.lastname: Sam
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Handley
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000600:supply & distribution / Q000627:therapeutic use*; D002160:Cambodia / Q000453:epidemiology; D018432:Drug Resistance, Multiple; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D010865:Pilot Projects; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D000995:Antitubercular Agents