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

(If annual incidence rates rather than case
numbers had been presented, the trends would
have been the same).
Here is my explanation for the trends shown
in the figure. At the national level, we are now
reaping the harvest of reinvesting in good TB
control. We have secured the necessary
funding and have applied those funds
strategically throughout the country to
strengthen surveillance and case finding, to
expand directly observed therapy for TB cases
in order to increase completion rates and
reduce acquired drug resistance, and to stop
nosocomial transmission and other pockets of
current transmission of TB.
Speaking in terms of a theory of TB control,
our investment has allowed us to regain the
ground that was lost during the resurgence by
applying to their best advantage our current
tools (this fact was noted in a JAMA editorial
written in 1997 by Drs. Bess Miller and Ken
Castro of the Division of TB Elimination). In
that sense, the drop in cases and case rates
nationally represent a reduction in “excess
morbidity” that arose during the time when
the national infrastructure was weakened in
relation to the strength of the dual epidemics
of TB and HIV, increased immigration from
high-prevalence areas, and person-to-person
transmission of TB, including nosocomial
transmission.
Some places such as Seattle, however, did not
experience the full power of the TB
resurgence. For example, we were only
modestly impacted by the HIV/TB
phenomenon, with rapid person-to-person
spread of disease, and MDR TB. Our
infrastructure had not been dismantled, and
we experienced less excess morbidity in those
bad days. In the decade of the 1990s, however,
even though we believe we have a good
program structure, a talented staff, and
funding sufficient to allow us to do good TB
control work, we have failed to effect a
meaningful reduction in TB morbidity in our
TB Control at the Millennium
38
community. In other words, we appear to
have reached an equilibrium with our target
disease, given its current epidemiological
pattern in our community. This experience is
the basis for my suggestion that it is possible
that the nation as a whole will also reach such
an equilibrium point, once its excess TB
morbidity has been “mopped up.” When that
point may be reached, and at what level of
morbidity, I of course cannot say.
I don’t want to leave the impression that we
have passively accepted the current status quo
in Seattle. We are aggressively attempting to
disrupt the equilibrium between TB and TB
control by learning more about the
epidemiology of TB in our community and by
increasing the effectiveness of our communitybased
TB control plan. For example, in our
community, persons born outside the US
account for 70%-75% of cases, and RFLP
survey data suggest that nearly all of our cases
in foreign-born persons arise through
reactivation of latent infection, including
persons who have received preventive therapy.
This information suggests that we need to
expand treatment of latent TB infection in
high-risk foreign-born persons; to accomplish
that, we have established a Preventive Therapy
Partnership Program with a number of health
care facilities that provide primary health care
to high-risk foreign-born persons. Also, given
that we regularly see TB occur in foreign-born
persons who have received preventive therapy
in the past, we are reevaluating the traditional
approach to preventive therapy, and have
secured funding to develop new approaches to
increase the uptake and completion of
preventive therapy by newly-arrived
immigrants and refugees.
Should the nation encounter such a “mud
hole” in the road to TB elimination, similar
strategies will be required to move beyond it.
ACET, in its recent publication, TB
Elimination Revisited: Obstacles, Opportunities,
and a Renewed Commitment, has made several
practical suggestions, including the need for