CDC History of Tuberculosis Control - Medical and Public Health ...

issue
recommendations,
OSHA has the
capacity to enforce its
standards. In 1997,
OSHA published a
draft TB standard in
the Federal Register.
Following the
publication of the
draft standard, there
was a period for
public comment
followed by a series of hearings for testimony.
Detailed comments were submitted from a
CDC committee including staff members of
NIOSH, the Hospital Infections Program, and
the Division of Tuberculosis Elimination, as
well as many other professional organizations.
In July 1999, OSHA reopened the docket for
further public comment. The OSHA TB
standard is currently undergoing revision, and
its final content and release date are not yet
known.
In order to better understand the risk of
transmission of M. tuberculosis to health care
workers, CDC undertook several studies
designed to examine rates of skin test
conversions in health care workers. The most
comprehensive of these was a study initiated
in 1995 called StaffTRAK-TB. This study
included over 13,000 health care workers.
Data from this study demonstrate a rate of
skin test conversions among health care
workers of 4.4 conversions per 1,000 personyears
of follow-up. For US-born persons, the
rate was even lower at 3.2 conversions per
1,000 person-years. From data currently
available from studies such as StaffTRAK-TB,
the risk of nosocomial transmission of TB
appears to be quite low. As a result CDC is
considering revision of the 1994 guidelines,
especially in the areas of frequency of
tuberculin skin testing of health care workers.
The risk of transmission of M. tuberculosis in
health care settings is a real one. However, the
TB Control at the Millennium
62
magnitude of this risk depends on many
factors such as implementation of
administrative and engineering controls,
prevalence of patients with infectious TB
within the facility, and risk for infection
outside of the healthcare facility. All of these
factors need to be weighed in decisions
regarding recommendations or mandates for
TB control measures within health care
facilities. As the rates of TB in the US
continue to decline, these recommendations
will need to be tailored to offer protection to
patients and workers within the health care
setting, without an unnecessary burden of
testing and expense.
A Decade of Notable TB Outbreaks:
A Selected Review
by Scott B. McCombs, MPH
Deputy Chief, Surveillance and Epidemiology Branch
The Surveillance and Epidemiology Branch is
charged with monitoring TB morbidity and
mortality in cooperation with state and local
health departments. One of the most
fascinating and important parts of our role is
to assist our partners in responding to
outbreaks of TB when they occur. This article
summarizes a cross-section of some of the
more notable outbreaks from the 1990s.
Extensive transmission of Mycobacterium
tuberculosis from a child (Curtis, Ridzon,
Vogel, et al. N Engl J Med 1999;341:1491-
1495).
Although young children rarely transmit TB,
infectious TB was diagnosed in a 9-year-old
boy in North Dakota in July 1998. The child
was screened because extrapulmonary TB was
diagnosed in his female guardian. The child,
who had come from the Republic of the
Marshall Islands in 1996, had bilateral cavitary
TB. Because he was the only known possible
source of his guardian’s TB, an investigation of
the child’s contacts was undertaken. Family,
school, day-care, and other social contacts
were notified of their exposure and given
tuberculin skin tests (TST). Of the 276