title: Transmission of tuberculosis in a South African community with a high prevalence of HIV infection.
abstract: BACKGROUND
  In settings of high tuberculosis transmission, little is known of the interaction between human immunodeficiency virus (HIV) positive and HIV-negative tuberculosis disease and of the impact of antiretroviral treatment (ART) programs on tuberculosis transmission dynamics.
  
  
  METHODS
  Mycobacterium tuberculosis isolates were collected from patients with tuberculosis who resided in a South African township with a high burden of tuberculosis and HIV infection. Demographic and clinical data were extracted from clinic records. Isolates underwent IS6110-based restriction fragment length polymorphism analysis. Patients with unique (nonclustered) M. tuberculosis genotypes and cluster index cases (ie, the first tuberculosis case in a cluster) were defined as having tuberculosis due to reactivation of latent M. tuberculosis infection. Secondary cases in clusters were defined as having tuberculosis due to recent M. tuberculosis infection.
  
  
  RESULTS
  Overall, 311 M. tuberculosis genotypes were identified among 718 isolates from 710 patients; 224 (31%) isolates were unique strains, and 478 (67%) occurred in 87 clusters. Cluster index cases were significantly more likely than other tuberculosis cases to be HIV negative. HIV-positive patients were more likely to be secondary cases (P = .001), including patients receiving ART (P = .004). Only 8% of cases of adult-adult transmission of tuberculosis occurred on shared residential plots.
  
  
  CONCLUSIONS
  Recent infection accounted for the majority of tuberculosis cases, particularly among HIV-positive patients, including patients receiving ART. HIV-negative patients may be disproportionally responsible for ongoing transmission.
authors: Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine Department of Medicine.
authors: Keren
authors: K
authors: Middelkoop
authors: Department of Epidemiology, Mailman School of Public Health, Columbia University, New York Public Health Research Institute Tuberculosis Center.
authors: Barun
authors: B
authors: Mathema
authors: Division of Epidemiology and Biostatistics, School of Public Health and Family Medicine, University of Cape Town.
authors: Landon
authors: L
authors: Myer
authors: Public Health Research Institute Tuberculosis Center.
authors: Elena
authors: E
authors: Shashkina
authors: Division of Medical Microbiology, University of Stellenbosch National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa.
authors: Andrew
authors: A
authors: Whitelaw
authors: Laboratory of Mycobacterial Immunity and Pathogenesis, Public Health Research Institute, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark.
authors: Gilla
authors: G
authors: Kaplan
authors: Public Health Research Institute Tuberculosis Center.
authors: Barry
authors: B
authors: Kreiswirth
authors: Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine Department of Medicine.
authors: Robin
authors: R
authors: Wood
authors: Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine Department of Medicine.
authors: Linda-Gail
authors: LG
authors: Bekker
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology*; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000235:genetics; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission* / Q000821:virology*
chemical_list: D044966:Anti-Retroviral Agents
keywords: HIV; genotyping; molecular epidemiology; transmission; tuberculosis