Outbreak investigations should include case finding and identification of exposed contacts so that tuberculin skin testing and screening for tuberculosis disease can be performed. Contact investigations are usually performed using a concentric circle approach, where contacts with the greatest exposure, such as household members, are identified and tested. If the rate of Mycobacterium tuberculosis infection is greater than expected, the investigation should move to the next highly exposed circle of contacts, such as work or school contacts. Subsequent concentric circles of contacts should be tested until the rate of infection is thought to be equal to that of the surrounding community.

Outbreaks represent experiments of nature, and while the first duty is interruption of transmission and identification and testing of exposed contacts, outbreaks also are an opportunity to learn valuable lessons. Examining missed opportunities that may have lead to the outbreak can point out areas within a tuberculosis control program in need of improvement or strengthening. This is clearly the case for the Florida Department of Corrections, and important steps have been taken to improve TB control.

In addition, new information about the pathogenesis and transmission of M. tuberculosis can be learned from outbreak investigations. Examples of lessons learned from outbreak investigations include that children, who were thought not to transmit infection, can be highly infectious; that M. tuberculosis can be transmitted through improperly disinfected bronchoscopes; and that in those with HIV infection, the time to development of tuberculosis disease after infection is accelerated when compared to those without HIV infection. In all cases, suspected outbreaks of tuberculosis should be reported promptly to public health authorities and investigations should be performed in conjunction with state and local tuberculosis control programs.

The algorithms included in this issue depict how to proceed when someone presents with suspected TB in the correctional setting, and the TB 101 details how to classify the tuberculin skin test reaction. At the conclusion of this issue, readers will be more familiar with TB treatment guidelines and how to prevent TB outbreaks in the correctional setting, know more about who should be tested for tuberculosis, and be aware of different tuberculin skin test reactions, and their implications. Let's all hope that this TB update prevents a few outbreaks of TB in the future.