Yaws: forgotten but not gone
Yaws is a chronic bacterial infection of the skin, bone and cartilage which occurs mainly in poor communities in warm, humid, tropical areas of Africa, Asia and Latin America. The disease is caused by the bacterium called Treponema pertenue, a Gram-negative Spirochete closely related to Treponema pallidum which causes syphilis. However, unlike syphilis, yaws is not sexually transmitted, but spreads through direct skin contact with an infected person. About 75% of the people affected are children under 15 years of age. Overcrowding, poor personal hygiene and poor sanitation facilitate the spread of the disease. Two to fours weeks after infection, a single skin lesion develops at the point of entry of the bacterium. Eventually, without treatment, multiple lesions appear all over the body, together bone lesions and pain. Yaws is rarely fatal, but untreated it results in chronic disfigurement and disability. Without treatment, about 10% of affected individuals develop disfiguring and disabling complications after five years because the disease causes gross destruction of the skin and bones. It can also cause deformities of the legs, nose, palate, and upper jaw. There is no vaccine to prevent yaws, so prevention are based on the interruption of transmission by early diagnosis and treatment of affected individuals and their contacts.
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Fortunately, as with other Spirochete diseases, yaws is very sensitive to a range of antibiotics, and a single injection of penicillin which costs as little as 32 US cents cures the disease. For those who are allergic to penicillin, tetracycline, erythromycin and doxycycline can be used.
Between 1950 and 1970, WHO and UNICEF led a worldwide campaign to control yaws in 46 tropical countries. Mass campaigns led to the treatment of 50 million people and by 1970, the prevalence of the disease had decreased by 95%. In the 1970s health care programmes in many countries were dismantled and resources for and attention to yaws programs gradually disappeared. By the late 1970s, the disease had began to creep back. In the 1990s, WHO estimated the global prevalence at 2.5 million, of which 460,000 were new cases. The true prevalence today is not known because there is no official notification of the disease globally. It is unclear if cases of yaws still occur in the Americas. Since 1995, there have been renewed elimination efforts in some regions and countries but there is no global coordination.
And yet …
Since yaws only occurs in humans and higher primates such as gorillas and a relatively cheap and effective treatment is available, experts believe it is possible that yaws could be completely eradicated. India has eliminated yaws, showing what is possible if political will and a modest amount of funding is present. The WHO has recently announced that it would like to eliminate yaws from Asia by 2012, and is considering a revival of its 1950s-style worldwide eradication plan. “The persistence of yaws in the 21st century is unacceptable;” says Dr Lorenzo Savioli, WHO Director of Neglected Tropical Diseases. “There is a cost-effective approach to treating this disease.”
In December 2006 the Bill & Melinda Gates Foundation committed to spending $83.5 million fighting malaria. Now, Windows Vista costs US$400. At 32 cents a shot, the same money could treat 1,250 yaws patients. So which should the Gates Foundation spend their money on first, malaria or yaws? You can email the Gates Foundation at info@gatesfoundation.org and tell Bill to put his hand in his pocket, pull out some small change and eliminate the scandal of this disease of poverty once and for all.
