Tuberculosis outbreak associated with a homeless shelter - Kane County, Illinois, 2007-2011.

Despite the overall decline in tuberculosis (TB) incidence in the United States to a record low, outbreaks of TB among homeless persons continue to challenge TB control efforts. In January 2010, public health officials recognized an outbreak of TB after three overnight guests at a homeless shelter in Illinois received diagnoses of TB disease caused by Mycobacterium tuberculosis isolates with matching genotype patterns. As of September 2011, a total of 28 outbreak-associated cases involving shelter guests, dating back to 2007, had been recognized, indicating ongoing M. tuberculosis transmission. The subsequent investigation found that all patients were homeless and had been overnight shelter guests. Excess alcohol use was common (82%), and two bars emerged as additional sites of potential transmission. Patients with outbreak-associated TB were treated successfully for TB disease. To prevent future cases of TB, public health officials are implementing a program to offer 12 once-weekly doses of isoniazid and rifapentine under direct observation for treatment of latent tuberculosis infection (LTBI) in this high-risk population. Although the United States has made progress toward TB elimination, this outbreak demonstrates the vulnerability of homeless persons to outbreaks of TB, highlighting the need for aggressive and sustained TB control efforts.