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

New Jersey Medical School National
Tuberculosis Center (Newark):
Web address: www.umdnj.edu/ntbc
Telephone: 973/972-3270
My Perspective on TB Control over the
Past Two to Three Decades
by Jeffrey Glassroth, MD
Prof of Medicine, Univ of Wisconsin Medical School
President, American Thoracic Society
In 1975 case rates for tuberculosis (TB) in the
United States were in double digits per
100,000. Increasingly, those patients were
individuals with serious social problems. A
major concern at CDC that year was the
screening for TB of newly arriving Vietnamese
refugees; the treatment of active cases was
provided, and notification to local health
departments of latently infected individuals
was undertaken. There was also concern about
the quality of immigrant screening done
overseas, but the major focus of “imported”
TB was along the border with Mexico.
Monitoring of TB drug resistance, particularly
primary resistance (i.e., among persons not
previously treated), was pursued and,
reassuringly, indications were found that these
rates were generally stable and low,
particularly with respect to rifampin. A major
treatment study was beginning and it would
help to define the role of rifampin in so-called
“short-course chemotherapy,” meaning 9
months of daily treatment as opposed to the
standard of 18-24 months that existed at the
time. “TB Today!,” an intensive educational
program that provided essential knowledge to
TB control staff from around the country,
presented material on TB microbiology and
diagnosis that emphasized the (then) state-ofthe-art
methods; a description of classical
microbiologic techniques that had changed
little in the near-century since Koch described
the tubercle bacillus. Also taught in the course
was a segment on optimizing the use and
interpretation of the tuberculin skin test for
identifying TB infection. A study was about
to begin to assess the importance of skin test
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boosting when sequential tuberculin tests were
applied. Much of what was underlying those
efforts with tuberculin skin testing actually
reflected concerns and frustrations with the
use of isoniazid (INH) for treating latent TB
infections, so-called TB prophylaxis. On the
one hand prophylaxis was effective but, on the
other hand, it came with a risk of side effects,
most notably hepatitis. The challenge was to
identify, via skin testing, the persons most
likely to derive benefit from INH and least
likely to be harmed by it; a classic benefit/risk
“equation.” BCG vaccination, though widely
used outside the US, was rarely used here,
because of perceived limited effectiveness and
problems with skin test interpretation.
The intervening quarter century has seen
remarkable changes with respect to TB but, in
some ways, little has changed. A number of
years ago, then–CDC Director Dr. James
Mason urged that CDC’s TB unit not think in
terms of TB “control” but of “elimination.”
The name of the unit changed to reflect this
new, more ambitious mission. Indeed, in the
US, after some years of rising rates, TB rates
are again falling and are a fraction of what
they were 25 years ago. However, in many
ways the challenges to TB elimination in the
US are greater today than a quarter century
ago. Worldwide, TB prevalence is increasing,
and today over 40% of cases reported in the
US are “imported” in the person of
immigrants from high-prevalence countries.
The worldwide TB burden is fueled by HIV
infection, an entity unknown in 1975, which
facilitates every aspect of the natural history of
TB from transmission to disease. In
recognition of this, and to more efficiently
combat these interrelated public health
problems, the TB division at CDC is now
administratively “housed” with the HIV
division. Moreover, CDC has dramatically
increased its worldwide collaborations to assist
in efforts at containing TB abroad.
Rifampin is now well entrenched as a
cornerstone of treatment, and several related