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SOCIAL MEDICINE Community-based Treatment Shows Success Against Resistant TBMultidrug-resistant tuberculosis no longer must be considered a death sentence for infected people living in poor nations, according to a study by a consortium of researchers led by HMS's Program in Infectious Disease and Social Change in the Department of Social Medicine.
A family in Peru mourns the loss of a child to tuberculosis. (Courtesy of Partners in Health and the HMS Dept. of Social Medicine) The study, which appears in the Jan. 9 New England Journal of Medicine, provides the first hard evidence that outpatient community care in poor, urban settings can work for this most difficult to treat form of the disease. The treatment model could ultimately help save hundreds of thousands of lives worldwide. Among those who completed at least four months of therapy, the percentage with probable cures in this community-based study was 83 percent, as high as any study reported to date, even in hospital settings. In contrast, the seminal report on the treatment of resistant TB in a referral hospital in the U.S. documented a favorable response in 65 percent of patients.
"Finding an end to this tragedy requires high-quality ambulatory care that can be delivered in resource-poor nations," said Mitnick. "This study reveals the effectiveness of our model against multidrug-resistant tuberculosis and offers new hope to those sick with this and other chronic infectious diseases." Targeting TBTB is a highly infectious bacterial disease transmitted by the coughs of those who are sick. The bacterium destroys the lungs and kills approximately two million people each year, making it one of the leading infectious causes of death worldwide. The World Health Organization declared TB a global emergency in 1993 and launched an aggressive, comprehensive program known as DOTS to eliminate the epidemic. The standardized short-course treatment regimen on which the DOTS model is based, however, usually fails to cure multidrug-resistant tuberculosis (MDR-TB).Two WHO studies, released in 1997 and 2000, found that MDR-TB strains were present in 63 of the 72 countries or regions surveyed; in some known TB hot spots, MDR-TB accounted for at least 20 percent of all previously treated TB cases. Strains of MDR-TB are resistant to the two most important drugs in the DOTS regimen and, therefore, existing therapy in poor countries has been inadequate. It has been argued that drug-susceptibility testing and second-line drugs are not cost-effective in these poor countries due to limited resources and that intensive clinical management is impossible because of a lack of infrastructure. But the collaborative model described in this study counters these assumptions. Working in Lima, Peru, where there is a TB epidemic with a high percentage of MDR-TB patients, the consortium developed a treatment model called DOTS-Plus. In it, urban patients receive directly observed individualized therapy. Community members in northern Lima were taught to care for MDR-TB patients, who in other nations would be hospitalized. These health promoters ensure that patients continue their medications, manage adverse drug events, keep patients well nourished, and provide other support services. Drug-susceptibility testing was conducted to determine which TB drugs were likely to be effective for each patient, and cultures were performed monthly to monitor the effectiveness of the treatments. Cure RatesThe consortium--which includes Partners in Health, an HMS-affiliated non-governmental organization; its Peruvian sister organization, Socios en Salud; and the Peruvian Ministry of Health--enrolled 75 patients in the study between August 1, 1996, and February 1, 1999. All of them had failed treatment in the DOTS program and were diagnosed with MDR-TB, with an average resistance to six of the approximately 13 TB drugs.Of these 75 patients, 66 completed four or more months of therapy, receiving 58 different regimens lasting a median of 23 months. At the completion of therapy, 55 of the 66 (83 percent) had probable cures, defined as at least 12 months of consecutive negative cultures during therapy. Five patients (8 percent) withdrew from therapy; therapy failed in 1 patient; and 5 patients (8 percent) died while receiving therapy, after more than four months in the program. "While developing a new model of care may not appear as dramatic as the discovery of a more effective drug, for those who might have otherwise been lost, this model brings similar hope," said Mitnick, who is also with Partners in Health. "Among the hundreds of families affected by this epidemic in northern Lima alone, we found scores who had resorted to desperate measures such as selling their land or livestock or prostitution to buy medicines for loved ones--often two, three, or four with MDR-TB in a household. Some had been told simply to save their money to 'buy their own coffins.'" "Our experience establishes that patients with chronic MDR-TB can be treated successfully as outpatients outside referral centers and in a resource-poor country," said Paul Farmer, the study's principal investigator and the Maude and Lillian Presley professor of social medicine and codirector of the Program in Infectious Disease and Social Change. "By moving treatment into the community, it is possible, without compromising the quality of therapy, to lower costs and reduce the risk of spread of MDR-TB. Successful community-based therapy for MDR-TB--and potentially HIV--provides hope for the tens of millions of patients who are suffering from chronic infectious diseases in settings with limited health infrastructure." --John Lacey |
