Update: An Airborne Killer Returns
- A new strain of tuberculosis
is set to hit Asia
- By Catherine Shepherd
- From
- TUBERCULOSIS, or TB, was once romanticized
as the "artist's disease" in the West. Wasted youth and wan complexions
found their way into countless 19th-century poems, paintings and novels.
Today, there is no such glamorization. According to a recent report by
the World Health Organization (WHO), TB has re-emerged more powerful and
more threatening than the outbreak that killed thousands last century.
The report, entitled Anti-Tuberculosis Drug Resistance in the World, details
the spread of a "super-strain" of TB-causing bacteria. Worse
still, the area poised to be hit hardest by the disease is Asia.
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- Several factors contribute to the danger
in the region. The first, perhaps ironically, is the widespread availability
of medication. Tuberculosis sufferers in Asia have had access to common
anti-TB drugs like isoniazid and rifampicin but have failed to take them
properly or completely. This has allowed the organism responsible for TB,
Mycobacterium tuberculosis, to mutate and build up resistance.
-
- Secondly, the region has several hundred
urban centers, where overcrowding and the constant movement of people can
lead to a rapid spread of the disease. The third factor is a familiar one.
"All of Asia is at high risk, but there is no greater risk than in
Southeast Asia, because HIV is moving so quickly," says Kraig Klaudt,
WHO's external advocacy officer. Tuberculosis spreads 30 times faster in
AIDS patients than in people whose immune systems are intact.
-
- Carried in sputum droplets, the bacteria
are transmitted through the air. Even getting into a cab that was occupied
by a TB patient three hours before can lead to infection. "There is
nothing a person can do to not get TB," says Klaudt. "You can
change your behavior to lower the risk of AIDS, but you cannot stop breathing."
-
- When inhaled, the bacteria are drawn
into the lungs where the tissues react to the invaders by coating them
with cells -- much the same way an oyster coats a sand grain to form a
pearl. The trouble is, these "pearls," or tubercles, grow larger
and larger, and eventually prevent the lungs from doing their job. The
first symptoms of infection are chest pain, loss of appetite, fever and
night sweats. Secondary symptoms: coughing up blood and pus, and severe
shortness of breath.
-
- The only program that has been effective
against tuberculosis is DOTS, or Directly Observed Treatment, Short-course.
Healthcare workers under this program do not just hand out medication;
rather, the patient is required to return to the clinic daily to be given
the proper dose and is monitored for any adverse reactions.
-
- But only 12% of TB patients were treated
with DOTS this year. Because it is more costly and complicated to operate
than simply dispensing pills, health officials have been slow to change
from their old TB management programs. WHO is calling on governments to
implement DOTS and urging citizens to make the same demand. After all,
there is no defense against the disease, except treating the infected.
WASHINGTON "Hot zones" of untreatable tuberculosis are emerging
around the world and threaten a global crisis, the World Health Organization
warned Wednesday. A study of 50,000 patients in 35 nations found that a
third of the countries have a form of TB resistant to multiple drugs. Untreatable
cases account for 2 percent to 14 percent of the world total. That number
is low, but WHO said lethal tuberculosis could spread rapidly because only
one in 10 patients gets medical care appropriate to curb drug resistance.
- "Hot zones" in India, Russia,
Latvia, Estonia, the Dominican Republic, Argentina and the Ivory Coast
have so much drug-resistant TB that it threatens to overwhelm local health
systems, said the study by WHO and U.S. health officials.
- "This study shows definitively,
and for the first time, what we most feared but could not previously prove:
Our world again faces the specter of incurable tuberculosis," said
Dr. Michael Iseman, TB chief at the National Jewish Medical and Research
Center in Denver, who reviewed the study. Drug-resistant TB "is on
every continent, probably in every country," he said.
- Tuberculosis is the world's top infectious
killer. It is spread through coughing and sneezing and can be highly contagious
-- the average patient infects 10 to 20 people a year.
-
- The World Health Organization announced
last spring that TB's global spread had finally leveled off, but the new
study looks specifically at killer drug-resistant forms. The normal variety
of tuberculosis often can be cured with a combination of four drugs taken
for six to eight months.
-
- But many patients, especially in poor
countries, stop taking the drugs when they feel better or run out of money,
which allows the TB still in their bodies to mutate so that one or more
medicines no longer work. This "acquired drug resistance" is
entirely preventable with proper care, WHO said.
-
- These people also can spread drug-resistant
(MDR) TB to new patients, a circumstance that gives patients what is called
"primary drug resistance." The WHO study found spots where resistance
to a single drug is alarmingly high -- It reached 100 percent of treated
but not cured TB patients in Ivanovo Oblast, Russia, about 180 miles east
of Moscow. These people can be treated with other drugs, but they're in
danger because the TB germ must make just one more mutation to become multidrug
resistant -- and lethal.
-
- The study identified "hot zones"
with multidrug-resistant TB at levels high enough to overwhelm local TB
control programs: * India's Delhi state, where 13 percent of all TB patients
are multidrug resistant. * Ivanovo Oblast, Russia, 7 percent. * Latvia,
22 percent. * Estonia, 12 percent. * Dominican Republic, 9 percent. * Argentina,
8 percent. * Ivory Coast, 5 percent.
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- Lowest levels of multidrug-resistant
TB were no cases in Kenya, less than 1 percent in Australia and New Zealand
and 2 percent in the United States. Levels of primary resistance, people
who caught a resistant strain, to any drug ranged from 2 percent in the
Czech Republic to 41 percent in the Dominican Republic.
-
- WHO said that to stem the spread of untreatable
TB, countries must invest in therapy called DOTS -- Directly Observed Treatment,
Short-course. Health workers watch patients swallow their four TB drugs
every day, then follow up to ensure they're cured or to identify drug resistance
early. DOTS is the standard in industrialized countries and has cut drug
resistance 85 percent in metropolitan areas such as New York City, WHO
said. By LAURAN NEERGAARD, The Associated Press
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