title: Increase in nontuberculous mycobacteria isolated in Shanghai, China: results from a population-based study.
abstract: BACKGROUND
  In China, the prevalence of nontuberculous mycobacteria (NTM) in isolates from mycobacterial culture-positive patients with pulmonary tuberculosis (TB) is largely unknown.
  
  
  METHODS
  We used conventional biochemical and 16S rRNA gene sequencing to identify species of mycobacteria in specimens from patients suspected of having TB. Drug-susceptibility testing was performed on NTM isolates using the proportion method. We also determined the independent risk factors associated with infection with NTM compared with infection with Mycobacterium tuberculosis.
  
  
  RESULTS
  The overall rate of NTM isolated from mycobacterial culture-positive patients was 5.9% in this population, with a significantly increasing trend from 3.0% in 2008 to 8.5% in 2012 (P for trend <0.001). The organism most frequently identified was M. kansasii (45.0%), followed by M. intracellulare (20.8%) and M. chelonae/abscessus (14.9%). The overall proportion of isolates resistant to the four first-line anti-TB agents were 64.6% for isoniazid, 77.6% for streptomycin, 63.3% for rifampicin and 75.1% for ethambutol. The risk factors most often associated with NTM infection were older age (P for trend <0.001), being a resident of Shanghai (adjusted odds ratio [aOR], 1.48; 95% CI, 1.10-2.00), having been treated for tuberculosis (aOR, 1.64; 95% CI, 1.18-2.29), having a cavity on chest X-ray (aOR, 1.51; 95% CI, 1.16-1.96), and being sputum smear-negative (aOR, 1.59; 95% CI, 1.16-2.18).
  
  
  CONCLUSIONS
  The prevalence of NTM isolated in Shanghai increased between 2008 and 2012, thus clinicians should consider NTM as a possible cause of TB-like disease. Accurate species identification is imperative so that proper treatment can be administered for diseases caused by the diversity of NTM species.
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Yangyi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Senlin
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Qichao
authors.initials: Q
authors.lastname: Pan
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000453:epidemiology* / Q000382:microbiology; D009170:Nontuberculous Mycobacteria / Q000187:drug effects / Q000302:isolation & purification* / Q000502:physiology*; D012307:Risk Factors; D055815:Young Adult