Fall 2001 Issue
Controlling Multidrug-Resistant Tuberculosis
Most Americans no longer consider tuberculosis a threat. Although this treatable and curable disease is at its lowest levels ever in the United States, it is one of the biggest killers worldwide, claiming nearly two million lives annually. About eight million people develop active cases of TB each year, and each can infect 10 to 15 others by coughing, sneezing, or simply breathing. With the increase in travel and immigration, national borders provide little defense against the transmission of TB.
A major concern of the public health community is the emergence of multidrug-resistant tuberculosis throughout the world, caused by strains of bacteria that standard drug treatments cannot cure. These bacteria develop resistance when individuals with tuberculosis are inappropriately treated, or they do not complete treatment regimens. When people with TB develop drug-resistant TB, the others they infect will have the same drug-resistant strain. The emergence of resistant forms of the disease, primarily among the poor and underserved, is compounded by the fact that many countries have poor TB control programs and some have none.
An innovative demonstration project underway in the shantytowns of northern Lima, Peru, offers hope for controlling drug-resistant TB in countries with limited resources. The project, called PARTNERS TB Control Program, involves a consortium of health organizations brought together by Harvard University and is funded by a grant from the Bill and Melinda Gates Foundation to address the problem of drug-resistant TB in Peru. Supported by a $2.1 million subcontract to the CDC Foundation from Harvard, CDC is providing technical assistance in epidemiology, infection control, community outreach, training, and cost analysis.
CDC project leader Kayla Laserson, S.D., S.M., EIS ‘97 says, “Under normal circumstances, treating tuberculosis is pretty straightforward. If a patient is compliant - that is, takes all the medication as prescribed - there is a high likelihood of cure.” Laserson, an epidemiologist with CDC’s Division of Tuberculosis Elimination, says most forms of tuberculosis are treated with a standard four-drug, six- to seven-month regimen that has been in use for the past decade.
However, treating drug-resistant TB requires a combination of what are called “second-line” drugs - those used when the “first-line” or standard treatment fails. These drugs are very expensive - $33,000 per patient in industrialized countries compared to $84 for first-line drugs. In addition, the second-line drugs need to be administered for longer periods of time, from 18 to 36 months. Because they are toxic with unpleasant side effects, people on a regimen of second-line drugs need to be monitored to ensure they take all the medication as prescribed and for the full period of time. Thus, treating drug-resistant TB requires both money and trained personnel to track patients, neither of which are likely to be available in many of the resource-poor nations where drug-resistant TB is emerging.
The Peruvian project employs two innovative tactics to address cost and compliance. It makes available second-line drugs obtained at substantially lower costs negotiated with pharmaceutical companies by a special World Health Organization committee - the Green Light Committee. Also, it employs lower-level health care workers and community volunteers to monitor patients for compliance.
“Getting the cost of the drugs down to affordable levels is one of the biggest hurdles in controlling drug-resistant TB,” says Alan Hinman, M.D., M.P.H., EIS ‘65, of the Task Force for Child Survival and Development and coordinator of the PARTNERS TB Control Program. “Most developing countries can’t afford usual market prices.
“Assuring completion of treatment is another major part of the effort,” Hinman says. “The Lima project demonstrates that you can train lower level health care workers and community volunteers to administer medications, recognize adverse events, and assure compliance. This reduces personnel costs.”
The five-year project in Lima is yielding a model for control of drug-resistant TB that can be expanded into other parts of Peru, as well as adapted for application in other countries. “Drug-resistant TB is an overwhelming problem in some developing countries,” says Kayla Laserson. “The Lima project offers one model for defeating tuberculosis in resource-poor countries.”
PARTNERS TB Control Program is a consortium that includes Harvard Medical School’s Partners in Health, its Peruvian chapter Socios en Salud, the Peru National TB Control Program, the Task Force on Child Survival and Development, the World Health Organization, and CDC.
- Rosemarie Perrin