Tuberculosis (TB) is a disease that is
spread from person to person through the
air. This disease is particularly dangerous
for persons infected with HIV. Worldwide, TB
is a leading cause of death among persons
infected with HIV [1].
This high level of risk underscores the
need for TB screening and preventive
treatment programs for HIV-infected persons
and those at greatest risk for HIV
infection. Everyone infected with HIV
should be tested for TB. Everyone infected
with TB should complete preventive therapy
as soon as possible to prevent progression
to TB disease.
THE NUMBERS
Worldwide
- At the end of 2007, approximately
33.2 million persons were living with
HIV infection [2].
- In 2007, approximately 2 billion
persons (one third of the world’s
population) were infected with
Mycobacterium tuberculosis, the
organism that is the most common cause
of TB in the United States [1].
- An estimated one third of the
persons living with HIV infection are
coinfected with TB [3].
- TB is the cause of death for as many
as half of all persons with AIDS [3].
- Since 1990, TB infection rates have
increased 4-fold in countries that are
heavily affected by HIV [3].
United States
- Approximately 1 million persons were
living with HIV infection at the end of
2003. As many as 25% of infected persons
are unaware of their infection [4].
- An estimated 9–14 million Americans
are infected with TB bacteria. If they
are not treated, TB will develop at some
point in about 5% to10% of these persons
[5].
- As of 2005, CDC estimated that 9% of
all TB cases and nearly 16% of TB cases
among persons aged 25 to 44 were
occurring in HIV-infected persons.
Because HIV infection so severely
weakens the immune system, persons
dually infected with HIV and TB,
compared with persons not infected with
HIV, are at very high risk for active TB
disease, which may be contagious [6].
- Of the TB patients reported (in
2005) to be infected with HIV, 63% were
non-Hispanic blacks [6].
PREVENTION CHALLENGES
Multidrug Resistance to TB
Multidrug-resistant TB (MDR TB) is TB
that is resistant to at least 2 of the best
anti-TB drugs—isoniazid and rifampin. MDR TB
is extremely difficult to treat and can be
fatal. Every nation must face the challenge
of combating MDR TB. People living with HIV
infection or with AIDS are at greater risk
of dying of MDR TB. Although the number of
cases in the United States decreased during
the past few years, MDR TB has now been
reported in nearly all states and the
District of Columbia [7,
8].
To prevent the continued emergence of drug-resistant strains of TB, treatment
for TB must be improved, not only in the United States but worldwide.
Inconsistent or partial treatment is the main cause of MDR TB. The most
effective strategy for ensuring the completion of treatment is directly observed
therapy (DOT), and its use must be expanded.
Treatment Interactions
Coinfection with HIV and TB presents
another challenge: possible complications
from interactions between the drugs used to
treat HIV and the drugs used to treat TB.
When prescribing these drugs, physicians
must carefully consider all potential
interactions.
WHAT CDC IS DOING
TB control is an exercise in vigilance. The goal of controlling and
eventually eliminating TB worldwide requires a focused, continual effort to
address the prevention and treatment needs of persons most at risk, including
those who are infected with HIV. Efforts to eliminate TB are therefore essential
to reducing the global toll of HIV infection.
Additional resources are as follows:
REFERENCES
- World Health Organization.
2007 Tuberculosis facts.
Accessed January 14, 2008.
-
Global summary of the AIDS epidemic,
December 2006.
Accessed January 7, 2008.
- UNAIDS.
Frequently asked questions about
tuberculosis and HIV.
Accessed January 10, 2008..
- Glynn M, Rhodes P.
Estimated HIV prevalence in the United
States at the end of 2003.
National HIV Prevention Conference; June
2005; Atlanta. Abstract
T1-B1101. Accessed January 19, 2008.
- CDC.
Controlling tuberculosis in the
United States: recommendations from the
American Thoracic Society, CDC, and the
Infectious Diseases Society of America.
MMWR 2005;54(RR-12):1-83.
- CDC.
Reported HIV status of
tuberculosis patients—United States,
1993–2005. MMWR 2007;56:1103-1106.
- CDC.
Extensively drug-resistant
tuberculosis—United States, 1993–2006.
MMWR 2007;56:250-253.
- CDC.
Reported Tuberculosis in the United States,
2006. Atlanta: US Department of
Health and Human Services, CDC; September
2007. Accessed January 15, 2007.
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