Transmission of tuberculosis in a South African community with a high prevalence of HIV infection

J Infect Dis. 2015 Jan 1;211(1):53-61. doi: 10.1093/infdis/jiu403. Epub 2014 Jul 22.


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.

Keywords: HIV; genotyping; molecular epidemiology; transmission; tuberculosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Retroviral Agents / therapeutic use
  • Female
  • Genotype
  • HIV Infections / drug therapy
  • HIV Infections / epidemiology
  • HIV Infections / microbiology*
  • HIV Infections / virology*
  • Humans
  • Male
  • Mycobacterium tuberculosis / genetics
  • Prevalence
  • South Africa / epidemiology
  • Tuberculosis / epidemiology
  • Tuberculosis / microbiology
  • Tuberculosis / transmission*
  • Tuberculosis / virology*


  • Anti-Retroviral Agents