TB Challenge: Partnering to Eliminate TB
in African Americans
Lessons Learned in a Mid-Western African-American
Community with Low TB Incidence and Program Resources
Dawn Tuckey, Program Consultant, DTBE/FSEB
From 2001 through 2004, a low-incidence state experienced an increase
in the number of tuberculosis (TB) cases. In March 2004, the state
department of health invited staff of CDC, the Division of Tuberculosis
Elimination, to assist the state and local health officials in an
epidemiologic investigation to prevent further spread of M. tuberculosis.
As a result of the investigation, a total of 26 TB cases were determined
to be outbreak related. Only cases that had a matching genotype
of M. tuberculosis or, when no isolate was available for genotyping,
an epidemiologic link to a previously identified case were included
as outbreak-related cases in the investigation.
During 2004, the county reported a total of 22 confirmed cases
of TB. The case rate (6.5 per 100,000) was more than three times
the TB rate of the entire state (2.1 per 100,000). Current data
indicate that 1,090 contacts to outbreak-related cases were identified.
Of the 26 outbreak-related cases, 10 (40%) had delayed diagnosis.
The median age was 27 years (range: 6 months 51 years), 25 (96%)
were African American, and 15 (58%) were female.
CDC staff determined that several factors contributed to this outbreak.
One factor was nonadherence to latent TB infection (LTBI) treatment
among the contacts. If four nonadherent contacts had completed the
LTBI treatment regimen, their own disease plus 16 additional cases
may have been prevented. A second contributing factor was delayed
diagnosis. This was caused by health care providers, as well as
the patient's own delay in accessing health care. For example,
health care providers in low-incidence areas may have a low index
of suspicion for TB. Patients, on the other hand, may delay seeking
medical care or may not disclose TB exposure to health care providers.
The delayed TB diagnosis in this outbreak emphasizes the importance
of educating both health care providers and patients about TB. Thirdly,
the need to expand contact investigations was a critical factor
in this outbreak.
Prior to CDC's involvement, the contact investigation had two limitations.
Even though 43% of the close contacts had a positive skin test result,
the initial contact investigation was not expanded beyond close
friends and family to include contacts at work and other social
settings. The second limitation was the lack of staff to manage
the TB patients and contacts; this occurs many times in low-incidence
areas where resources are limited.
Thus, the lessons learned from this outbreak are as follows: (1)
ensure completion of testing and treatment of contacts, (2) treat
persons with LTBI and TB disease using directly observed therapy
to ensure adherence, and (3) provide TB education to health care
providers and the community.
This investigation also illustrates what can happen in a low-incidence
area with limited TB resources, which is not uncommon in the United
States. Therefore, this outbreak provides lessons for TB control
by emphasizing the continued threat of TB in the United States,
the importance of successful execution of TB control measures, and
the need for resources to achieve prompt public health responses.