title: Transmission pattern of drug-resistant tuberculosis and its implication for tuberculosis control in eastern rural China.
abstract: OBJECTIVE
  Transmission patterns of drug-resistant Mycobacterium tuberculosis (MTB) may be influenced by differences in socio-demographics, local tuberculosis (TB) endemicity and efficaciousness of TB control programs. This study aimed to investigate the impact of DOTS on the transmission of drug-resistant TB in eastern rural China.
  
  
  METHODS
  We conducted a cross-sectional study of all patients diagnosed with drug-resistant TB over a one-year period in two rural Chinese counties with varying lengths of DOTS implementation. Counties included Deqing, with over 11 years' DOTS implementation and Guanyun, where DOTS was introduced 1 year prior to start of this study. We combined demographic, clinical and epidemiologic information with IS6110-based restricted fragment length polymorphism (RFLP) and Spoligotyping analysis of MTB isolates. In addition, we conducted DNA sequencing of resistance determining regions to first-line anti-tuberculosis agents.
  
  
  RESULTS
  Of the 223 drug-resistant isolates, 73(32.7%) isolates were identified with clustered IS6110RFLP patterns. The clustering proportion among total drug-resistant TB was higher in Guanyun than Deqing (26/101.vs.47/122; p,0.04), but not significantly different among the 53 multidrug-resistant isolates (10/18.vs.24/35; p,0.35). Patients with cavitary had increased risk of clustering in both counties. In Guanyun, patients with positive smear test or previous treatment history had a higher clustering proportion. Beijing genotype and isolates resistant to isoniazid and/or rifampicin were more likely to be clustered. Of the 73 patients with clustered drug-resistant isolates, 71.2% lived in the same or neighboring villages. Epidemiological link (household and social contact) was confirmed in 12.3% of the clustered isolates.
  
  
  CONCLUSIONS
  Transmission of drug-resistant TB in eastern rural China is characterized by small clusters and limited geographic spread. Our observations highlight the need for supplementing DOTS with additional strategies, including active case finding at the village level, effective treatment for patients with cavities and drug susceptibility testing for patients at increased risk for drug-resistance.
authors: Key Laboratory of Public Health Safety, Ministry of Education, and Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China.
authors: Yi
authors: Y
authors: Hu
authors: Barun
authors: B
authors: Mathema
authors: Weili
authors: W
authors: Jiang
authors: Barry
authors: B
authors: Kreiswirth
authors: Weibing
authors: W
authors: Wang
authors: Biao
authors: B
authors: Xu
references: Lancet. 2006 Nov 4;368(9547):1575-80
references: 17084757
references: Int J Tuberc Lung Dis. 2007 Apr;11(4):436-42
references: 17394691
references: Clin Infect Dis. 2010 May 15;50 Suppl 3:S231-7
references: 20397953
references: Lancet. 2007 Feb 24;369(9562):691-6
references: 17321314
references: Int J Tuberc Lung Dis. 2010 Feb;14(2):210-6
references: 20074413
references: J Clin Microbiol. 2002 Aug;40(8):2716-24
references: 12149319
references: J Clin Microbiol. 2008 Nov;46(11):3576-84
references: 18753356
references: Int J Tuberc Lung Dis. 2005 Jan;9(1):81-6
references: 15675555
references: Kekkaku. 2004 Feb;79(2):47-53
references: 15031999
references: Lancet. 2009 May 30;373(9678):1861-73
references: 19375159
references: Int J Tuberc Lung Dis. 2005 Sep;9(9):970-6
references: 16158889
references: J Microbiol Methods. 2005 Nov;63(2):165-72
references: 15893392
references: JAMA. 1997 Oct 1;278(13):1073-7
references: 9315765
references: J Med Microbiol. 2008 Dec;57(Pt 12):1518-1522
references: 19018023
references: J Infect Dis. 2007 Mar 15;195(6):864-9
references: 17299717
references: East Mediterr Health J. 2008 Nov-Dec;14(6):1240-5
references: 19161099
references: Epidemiol Infect. 2003 Jun;130(3):481-3
references: 12825732
references: Emerg Infect Dis. 2002 Nov;8(11):1320-6
references: 12453364
references: J Clin Microbiol. 1993 Feb;31(2):406-9
references: 8381814
references: BMC Microbiol. 2006 Oct 10;6:90
references: 17032442
references: Clin Infect Dis. 1997 Jan;24 Suppl 1:S121-30
references: 8994791
references: Epidemiol Infect. 2011 Jan;139(1):130-8
references: 20429968
references: Infect Genet Evol. 2006 Nov;6(6):491-504
references: 16632413
references: Am Rev Respir Dis. 1970 Jul;102(1):97-100
references: 4316799
references: Microb Drug Resist. 2008 Sep;14(3):227-32
references: 18707239
references: BMC Infect Dis. 2010 Feb 28;10:43
references: 20187977
references: J Clin Microbiol. 2009 Feb;47(2):335-44
references: 19036933
references: BMC Public Health. 2009 Jun 29;9:211
references: 19563647
references: BMC Infect Dis. 2009 Aug 06;9:122
references: 19660112
references: Lancet. 2007 Oct 27;370(9597):1500-7
references: 17964351
references: J Clin Microbiol. 2008 Sep;46(9):3005-11
references: 18614651
references: PLoS Med. 2006 Jul;3(7):e241
references: 16796403
references: Int J Tuberc Lung Dis. 2008 Nov;12(11):1300-5
references: 18926041
references: Biomed Environ Sci. 2010 Jun;23(3):188-93
references: 20708497