Tuberculosis among the homeless, United States, 1994–2010

OBJECTIVES: 1) To describe homeless persons diagnosed with tuberculosis (TB) during the period 1994–2010, and 2) to estimate a TB incidence rate among homeless persons in the United States.

METHODS: TB cases reported to the National Tuberculosis Surveillance System were analyzed by origin of birth. Incidence rates were calculated using the US Department of Housing and Urban Development homeless population estimates. Analysis of genotyping results identified clustering as a marker for transmission among homeless TB patients.

RESULTS: Of 270 948 reported TB cases, 16 527 (6%) were homeless. The TB incidence rate among homeless persons ranged from 36 to 47 cases per 100 000 population in 2006–2010. Homeless TB patients had over twice the odds of not completing treatment and of belonging to a genotype cluster. US- and foreign-born homeless TB patients had respectively 8 and 12 times the odds of substance abuse.

CONCLUSIONS: Compared to the general population, homeless persons had an approximately 10-fold increase in TB incidence, were less likely to complete treatment and more likely to abuse substances. Public health outreach should target homeless populations to reduce the excess burden of TB in this population.