Tuberculosis and MDR-TB
A curable disease that kills millions in the developing
world, tuberculosis offers a glaring example of global inequalities in access
to health care. Drugs to fight tuberculosis (TB) have been in existence for
50 years, and deaths from TB are rare in rich countries. Yet TB kills 5,000
people every day, nearly 2 million people per year. More than 2 billion people,
almost one-third of the world’s population, are infected with the microbes
that cause TB.
TB and HIV/AIDS
In recent years, the tuberculosis epidemic has intensified alongside another global plague of the poor: HIV/AIDS. People whose immune systems have been weakened by HIV are particularly vulnerable to catching and dying from TB. The spread of HIV has led to millions of new TB infections—particularly in sub-Saharan Africa—making TB the leading cause of death for people infected with HIV/AIDS. Because of this destructive relationship, the PIH model of care for HIV emphasizes coordination with expanded calls for aggressive treatment of tuberculosis in people living with HIV/AIDS.
If TB patients in treatment do not take each medication at the prescribed time or are unable to complete the full course of treatment, their tuberculosis may become resistant to those medications. To avoid the development of resistant TB, patients typically take TB medications under the supervision of health workers, a method known as Directly Observed Therapy, or DOT.
Over the past 15 years, however, incomplete TB treatments—due to shortages of medicines and medical personnel, civil disruptions, and socioeconomic barriers for patients—have led to a proliferation of strains of tuberculosis resistant to two or more TB medications. These strains, known as multi-drug resistant tuberculosis, or MDR-TB, are now present throughout the world.
MDR-TB can be treated and cured. But treatment regimens are complicated, lengthy
and expensive. Medications that are currently available can produce crippling
side effects and are less effective than drugs for non-resistant TB. If
left untreated, however, MDR-TB not only kills the patients but can spread
to other people, where it may develop additional drug resistance.
Extremely virulent strains of tuberculosis (XDR-TB) that are resistant to three or more of the second-line drugs used to treat MDR-TB have reached epidemic proportions in several areas. One outbreak in KwaZulu-Natal, South Africa, killed 74 of 78 patients within a matter of weeks, sparking fears that XDR-TB could spread rapidly and lethally, particularly in areas with high prevalence of HIV infection. In September 2006, the World Health Organization issued an alert regarding the emergence of XDR-TB.
Leading the fight against MDR-TB in Peru and Russia
PIH has been a world leader in developing and demonstrating the effectiveness
of clinical regimens and community-based strategies for combating MDR-TB in
resource-poor settings. In
partnership with our sister organizations in Peru and Russia, PIH has published
clinical care manuals for management of MDR-TB in English, Spanish and Russian. And
PIH continues to advocate for expanding access to treatment for TB, and for
development of new, more effective drugs to combat the disease.
When an epidemic of MDR-TB was discovered in the shantytowns of northern Lima, Peru, in 1996, PIH and its Peruvian affiliate, Socios En Salud (SES), initiated the world’s first community-based treatment program for MDR-TB in a resource-poor setting. SES was the lead organization in this effort, which created a treatment strategy to cure patients infected with MDR-TB and stop ongoing transmission. At a time when the World Health Organization (WHO) and the Peruvian Ministry of Health considered treatment of MDR-TB impractical and unaffordable, SES trained and hired people from the community to accompany patients through the long and arduous course of treatment with difficult-to-obtain second-line drugs. The result was a comprehensive approach to MDR-TB that enhanced access to care and achieved one of the highest cure rates for MDR-TB ever reported, an astonishing 83 percent.
The success of Socios En Salud’s patients in Peru made a powerful case
for treating MDR-TB in developing countries. In 2002, the WHO agreed and began
approving treatment plans for MDR-TB on a country-by-country basis. Four
years later, in 2006, new guidelines for treatment of MDR-TB were released
jointly by the WHO and other leaders in the fight to stop TB, including the
U.S. Centers for Disease Control and Prevention and PIH. The guidelines were
accompanied by a plan to increase the number of MDR-TB patients receiving treatment
worldwide from 16,000 in 2006 to a total of 800,000 by 2015.
The new guidelines for treatment of MDR-TB were also influenced by research
documenting the success of PIH's MDR-TB program in Siberia. Russia’s
epidemic of drug-resistant tuberculosis is among the worst in the world. In
Tomsk Oblast, Siberia, where PIH has been working since 1998 to expand the
MDR-TB model developed in Peru, 14 percent of patients newly infected with
TB are multi-drug resistant. The TB epidemic is especially complex in
the prison system, where drug resistance is even more prevalent.
PIH-Russia has worked to strengthen MDR-TB care for patients, particularly those in prisons, by renovating TB hospitals, training medical personnel, and distributing educational materials on MDR-TB throughout the former Soviet Union. By February 2005, the first group of MDR-TB patients in Russia had achieved a 78 percent cure rate, and nearly 1,700 TB and MDR-TB patients had received support from PIH-Russia. PIH-Russia and Boston staff have also worked to develop and carry out a research agenda that has demonstrated the effectiveness of treatment and disproved theories that adding treatment for MDR-TB would undermine the standard Directly Observed Treatment, Short Course (DOTS) program for non-resistant TB.