New Report Confirms Global Spread of Drug-Resistant Tuberculosis
WASHINGTON, Oct. 22 /PRNewswire/ -- An unprecedented report jointly released today by the top U.S. and
international health agencies confirmed that tuberculosis ''hot zones'' are emerging around the world where people are nearly
helpless to protect themselves from drug resistant strains, and which could soon ignite a new wave of virtually incurable
tuberculosis worldwide.
''This report provides the first scientific evidence for what we most feared but could not previously prove: the world again
faces the specter of incurable tuberculosis,'' said Dr. Michael Iseman, of the University of Colorado and National Jewish
Medical and Research Center in the U.S. ''Today in the developing world, multidrug-resistant (MDR) TB is usually a death
sentence.''
The study, titled Anti-Tuberculosis Drug Resistance in the World, was conducted by the World Health Organization (WHO),
The Centers for Disease Control and Prevention (CDC) and the International Union Against Tuberculosis and Lung Disease
(IUATLD), with financial support from the United States Agency for International Development (USAID). The study is
based on quality control and proficiency testing performed by an international network of 22 prestigious laboratories, as well
as actual surveys done in 50,000 TB cases in 35 countries.
In each of the ''hot zones,'' the disease is often resistant to the commonly prescribed drugs isoniazid and rifamplcin. This
makes TB an incurable disease for anyone who does not have access to the most sophisticated and expensive healthcare. In
industrialized countries, MDR-TB can raise treatment costs 100-fold -- up to US$250,000 per patient.
One-third of the countries surveyed had MDR-TB levels in between 2 and 14 percent of all cases. This would suggest that
there are already many countries with 1,000 or more MDR-TB cases.
The hot zones identified in the report include India, Russia, Latvia, Estonia, the Dominican Republic, Argentina and the Ivory
Coast. Scientists expressed concern that many of the hot zones are regional centers of travel, emigration and international
economic activity, and admitted that little can be done to prevent people infected with drug-resistant TB from travelling and
spreading the bacilli to other countries.
The survey did find evidence that most drug-resistance can be prevented by addressing the bad TB treatments practices
which initially cause it. The report documents for the first time the link between poor treatment of tuberculosis and the spread
of drug resistant strains. Conversely, where a TB treatment strategy known as DOTS is in place, the level of drug resistance
is low.
''While this study demonstrates a dangerous problem, it also directs us to a powerful solution knows as DOTS,'' said Dr.
Arata Kochi, Director of the WHO Global TB Programme. ''DOTS cures sick patients and prevents drug resistance.
Alarmingly, only about one in ten patients today has access to DOTS. We have to quickly put more DOTS programmes in
place to stop MDR-TB from increasing.''
Inconsistent or partial treatment of TB is the root cause of MDR-TB. Many patients fail to take all their medicines
consistently because of the extended treatment period or because they no longer have any of the outward symptoms of the
disease. In addition, many doctors and health workers prescribe the wrong drugs or the wrong combination of drugs. DOTS
addresses many of these issues.
''No one can afford to ignore the growing incidence of drug-resistant TB,'' said USAID Administrator J. Brian Atwood. ''An
epidemic of drug-resistant TB will have global implications that all countries must immediately recognize.''
''MDR-TB is an airborne bacterium that is spread just as easily as regular TB. An individual who is sick with any strain of TB
will infect between 10 and 20 people each year with that same strain,'' said Dr. Paul Nunn, Chief, Tuberculosis Research and
Surveillance Unit of the WHO Global TB Programme. ''The only way to prevent the spread of MTR-TB is to treat new TB
cases correctly -- and cure them. This prevents drug resistance from ever developing.''
The study found that levels of resistance to a single drug -- usually isoniazid -- are alarmingly high. Presence in the community
of single drug resistance means that the tuberculosis bacillus has to mutate just once more to achieve multidrug-resistance --
making the disease more deadly and difficult to treat.
Each of the identified hot zones has MDR-TB levels that threaten to overwhelm current TB control programmes and spread
disease to populations throughout the world. In Latvia, for example, 22 percent of TB patients had resistance to two or more
anti-TB drugs.
The region of Russia surveyed showed a 7 percent rate of multidrug resistance among TB patients, in the Dominican
Republic, there was 9 percent combined resistance, and in Delhi State, in India, 13 percent of all TB patients were ill with
MDR-TB.
The DOTS strategy focuses on the cure of every TB case. Good TB control which cures patients has proved successful in
preventing drug resistance in Algeria, Chile, Korea, Tanzania and New York City. Dramatic neglect of these well-known
principles is what has fuelled the global TB epidemic and is why WHO declared TB a Global Health Emergency in 1993.
DOTS provides a standardized combination of the most effective medicines, ensures through direct observation that these
medicines are taken regularly until patients are cured, and monitors patients' overall progress so that action can be taken if
cure is not being achieved.
The United States is not immune to the dangers of drug-resistant TB. CDC recently released a separate study which found
existence of drug-resistant TB in 42 U.S. states. While the number of individuals infected with drug-resistant TB in the U.S.
has declined, the number of states where drug-resistant TB was identified grew from 13 to 42 over the last six years.
''The data speak for themselves. The science points to simple cause and effect -- proper TB control programmes prevent the
mutation of drug-resistant strains of TB,'' said Dr. Adalbert Lazio, Chairman of the Bacteriology Section of the IUATLD.
''MDR-TB is a human-made phenomenon. We have the know-how to prevent MDR-TB and, as this study underscores, it is
time we applied it.''
In calling for the wider use of DOTS, WHO recommended that TB hot zones also are targeted for additional surveillance of
TB drug-resistance, similar to the effort that culminated in the study released today. WHO urged that hot zones of increasing
emigration, such as Eastern Europe and Russia, be paid close and urgent attention.
''Tuberculosis was one of the greatest health challenges of the early 20th century. We cannot allow MDR-TB to become the
biggest health threat of the 21st century,'' said Dr. Iseman. |
