Tuberculosis is one of the oldest diseases of
humans. Also known as the "galloping consumption" or "great white
plague", this affliction has scourged the world for centuries. While our grandparents
lived in fear of its dreaded reputation and deadly consequences, "TB" causes
little concern to most present-day Americans. Few realize that around the turn of the 20th
century, more Americans died of tuberculosis than any other cause of death. The battle
against TB began to be waged in 1944 by the United States Public Health Service and its
innovative control programs. The end result of this massive effort has been a reduction in
the number of tuberculosis cases from almost 130,000 per year in 1944 to 24,400 in 1989.
Tuberculosis sanitariums - hospital complexes built specifically to care for TB afflicted
individuals - are now memories to most older doctors, their beds either empty or turned
over to others with more pressing medical problems.
In a vast nation of more than 250 million people,
a "mere" 24,000 Americans cases of tuberculosis reported in a single year
doesn’t exactly sound like an epidemic (worldwide, the problem is much bigger.) What
concerns U.S. public health authorities, however, is a worrisome trend upwards. After
decades of declining figures the number of TB cases has slowly begun to swell. Societal
problems such as AIDS, poverty, homelessness, alcohol and drug abuse as well as an
increasing nursing home population are reversing the previously downward trend. Another
disturbing aspect is a resurgence of pediatric patients with tuberculosis. All of this has
served to revive dark memories of the days when TB was a major health threat in this
country.
Tuberculosis is caused by a rod shaped
bacteria-like organism called Mycobacterium tuberculosis. It is spread by droplets
contaminated with the bacteria that are expelled into the air when an adolescent or adult
with active pulmonary TB coughs or sneezes. Singing, loud speech, or even laughing may
also scatter the organism. The TB bacterium in these excretions is so tiny that they dry
out and, floating on air currents, may survive for long periods. When inhaled, the smallest
droplets end up in the alveoli, the lung’s smallest air sacs. There, in a protective
reaction, the body walls off the TB bacilli into tiny, hard, tissue masses called
tubercles. The Mycobacterium tuberculosis may remain dormant in an infected person
for months, years, or a lifetime, and may not be contagious to others. About 2 to 10 weeks
after tubercle formation, the infected person develops a positive reaction when given a
tuberculosis skin test. Most will generally test positive for the rest of their
lives.
Once infected, a lifelong balance between the
bacterium and the immune system is maintained unless the organism is
eradicated with therapy. If your resistance is lowered because of illness,
fatigue, malnutrition, malignancy, or any other factors, this balance may be upset,
allowing bacteria to break out of the capsules and enter the blood stream, causing active
disease. An important distinction is the one between tuberculosis infection and
tuberculosis disease. A person with infection has acquired the Mycobacterium
tuberculosis (as evidenced by a positive skin test) but has no symptoms and has a
normal chest x-ray. A person with tuberculosis disease, on the other hand, has symptoms
such as cough, weight loss, swollen lymph nodes, fever, and loss of appetite as well as
x-ray evidence of tuberculosis and a positive skin test. Only about 10% of people with
tuberculosis infection develop the active disease, the greater majority of these kids
being in the preschool age group.
The current epidemic of the human immunodeficiency
virus (HIV) is one of the main reasons for an increase in new cases of TB. Since HIV, the
virus that causes AIDS, impairs the body’s immune system, people with the infection
are at a higher risk to either develop a primary TB infection or reactivate a latent but
previously controlled case of TB.
The growing numbers of homeless are also
contributing to rising statistics. 7 percent of America's homeless have active TB, and
another 50 percent have TB infection. The crowded and less than sanitary conditions in
many homeless shelters and the lack of adequate medical care provide a fertile breeding
ground for the disease. Increasing enrollment of the elderly in nursing homes is also
leading to the rising incidence of TB. Other factors leading to a greater number of cases
are crowded living conditions, poor nutrition, poverty, stress, drug use, alcoholism, and
immigration into the United States from areas where TB is common.
There were 1,200 kids diagnosed with TB during
1990, up 9.4 percent from 1989. Since most kids lack the major risk factors for
contracting the disease, most were probably exposed to tuberculosis by adults such as
family members, day care workers, nannies, housekeepers, babysitters, teachers, etc.
Probably these adults did not even know that they had active tuberculosis. Every year
thousands more are apparently infected in this manner but thankfully do not get
the active disease. However, his adds to the pool of those at risk of developing active TB
in the future and is a likely occurrence if ever their immune system became unable to
control the mycobacterium.
Common sense would dictate that anybody with
symptoms suggestive of TB or who has been in close contact with someone with active TB
should first have a skin test, known as a PPD. Kids usually receive a TB skin test at
their yearly checkups, especially when entering kindergarten or day care. If a person has a
significant reaction upon being skin tested for the first time, additional laboratory
tests and a chest x-ray are usually performed to determine if the person has an active form
of TB.
The type of treatment for TB depends upon whether
or not the person has active tuberculosis. People with a positive tuberculin
test but without evidence of active disease receive an anti-tuberculosis drug called
Isoniazid. Studies have shown that this medication given for at least nine months will
protect the individual infected with tuberculosis against the development of active
disease for at least 20 years or more. People with a positive skin test, but without
active disease, should be allowed to remain in school or work, as they are not
contagious. The source of the infection in these situations is usually an adult -- a
teacher, parent, or bus driver, for example, and but not another kid. People with tuberculosis disease are treated with two additional anti-tuberculosis
medication in addition to isoniazid. Adults become noninfectious 2-4 weeks after starting
adequate therapy; kids are rarely contagious to others since their lung lesions are
small and their cough is minimal if present at all. Therefore, kids with
tuberculosis do not need to be isolated from family members, friends, or classmates.
Tuberculosis must be reported to the local health
department; Notification of a case of tuberculosis will help public health authorities
track down the infectious source and provide antituberculosis medication free to patients.
This effort will help to significantly reduce spread of the disease.
Many are of the opinion that the resurgence of tuberculosis has
occurred primarily due to failure in addressing important social issues. During the past
10 years, drug abuse, AIDS, and homelessness have left a large segment of our population
defenseless against the tuberculosis germ, and the organism has taken advantage of the
situation. Adequate detection and proven therapy for tuberculosis disease, advantages that
were not present almost one hundred years ago, are readily available to doctors in 1992.
Attention now needs to be focused on the preventive aspects of this communicable and
debilitating disease. More respect is due to Mycobacterium tuberculosis if we are
to avoid a return to the days when TB struck home in all segments of our society. The
experience of our grandparents should serve as a powerful reminder of the true health
hazards that this disease presents. Let’s heed their warnings well.
