WHO's Leprosy-Elimination Program Targets Brazil

In memoriam Baba Amte: a review of the worldwide status of leprosy.

 

First described in the 6th century BCE, leprosy is a chronic, nonfatal disease due to infection with the acid-fast bacillus Mycobacterium leprae. Following inoculation with the organism and a lengthy incubation period of years or even decades, clinical illness typically manifests in the cooler parts of the body—the skin, peripheral nerves, anterior eye, upper respiratory tract, and testes. Untreated, the disease is notorious for causing permanent disfigurement and deformity—often the result of neuropathy-associated injury—which consequently leads to social stigma and isolation.

 

Despite the historical segregation of lepers in colonies, the disease is not highly contagious. In untreated individuals, M. leprae is most likely transmitted to close and frequent contacts by means of respiratory droplets; however, transmission through colonized soil has also been postulated. Infected individuals are no longer contagious, however, after the first dose of multidrug therapy (dapsone, rifampicin, and clofazimine), and within 12 months of treatment, the disease is cured with (according to WHO) virtually no risk of relapse. Leprosy-related disability is averted with early treatment.

 

In 1991, the World Health Assembly resolved to eliminate leprosy (that is, to reduce the prevalence rate to <1 case per 10,000 persons) by the year 2000, and WHO claims that this goal overall was achieved. From 1985 to 2007, the number of world citizens affected by leprosy dropped by 96%, from 5.2 million to less than 225,000. As of 2007, leprosy was virtually eradicated in all but 4 of 122 countries where the disease was believed to be a public health problem in 1985 (Wkly Epidemiol Rec. 2007;82:225-32; Wkly Epidemiol Rec. 2007;82:388). Leprosy cases in these 4 countries—Brazil, the Democratic Republic of the Congo, Mozambique, and Nepal—accounted for nearly one quarter of all new cases globally in 2006 and one third of all registered cases at the beginning of 2007, according to WHO.

 

The number of leprosy cases in Brazil (60,567) makes up approximately half of all registered cases in the Americas. The National Hansen’s Disease (Leprosy) Program indicates that 166 new cases of leprosy were reported in the United States in 2005 (the most recent year for which data are available), and 60% of these cases occurred in 5 states: California, Texas, Louisiana, Massachusetts, and New York.* Although leprosy in the United States has been reported to affect immigrants preferentially, approximately half of the individuals infected in 2005 described themselves as white.

 

WHO advises that those with leprosy can receive free multidrug therapy from the organization, through a donation from Novartis and the Novartis Foundation for Sustainable Development. WHO acknowledges that the stigma of leprosy continues to hinder self-reporting and treatment and urges that “[a] new environment, in which patients will not hesitate to come forward for diagnosis and treatment at any health facility, must be created.”

 

*Notably, 9-banded armadillos are believed to be a reservoir for M. leprae in the United States; 15% of these animals in Texas and Louisiana are reported to be infected with the organism.