The World Health Organization (WHO) announced this year that only 396 cases of Guinea worm disease had been diagnosed in four African countries in the first half of 2012, down from twice that many in the first half of 2011 and millions throughout Africa and Asia during the 1980s. The WHO thinks that sometime in the next couple of years Guinea worm will become the second known disease, after smallpox, to be completely eradicated.
The disease is a painful parasitic affliction caused by a long, threadlike worm that grows in the patient's body, usually in joints and extremities, after being ingested in contaminated water. Although usually not fatal, it is debilitating for up to months on end and can wreak economic devastation on the communities it afflicts. There's no known cure, and the only remedy is pulling out the worm through a skin blister -- a brutally painful operation that some scholars think may have inspired the ancient snake-and-staff symbol used by the medical profession. The disease has been known to afflict humans for thousands of years, and Guinea worms have even been found in the bodies of Egyptian mummies. Although once common throughout Asia and the Middle East, the worm owes its name to its former prominence on Africa's west coast.
The successful war on the worm has been long in the making. In 1986, former U.S. President Jimmy Carter, along with the WHO and the U.S. Centers for Disease Control and Prevention, spearheaded an effort to eliminate Guinea worm disease at a time when 3.5 million people were affected. Unlike with other diseases, the campaign against Guinea worm has focused not on developing a cure, but on educating people about how it spreads and improving water quality in affected areas. Ninety-nine percent of the cases remaining are in newly independent South Sudan, so whether the worm can be eradicated entirely may depend on whether the country's fragile peace can be maintained.
COMEBACK BUGS Guinea worm may be down and almost out, but doctors worry that the following nasty diseases are poised to pick their heads off the mat. Tuberculosis TB has been treatable for decades through a six-month antibiotics course. But poor-quality diagnoses, treatment, and medicines contributed to the rise of 8.7 million new cases in 2011, particularly in Eastern Europe, India, China, and parts of Africa. Leprosy As early as 600 B.C., leprosy was stigmatized in China, Egypt, and India. The modern world has an effective treatment regimen, and in 1991 the WHO set a goal of eliminating the disease by 2000. Yet 219,000 new cases were reported last year, mostly in Africa and Asia. Gout The disease of medieval kings has returned to hobble average Westerners who now have a king's capacity for indulging in rich diets. Six million Americans report suffering from the disease, which causes intense pain in the joints, and rates have more than doubled since the 1960s. Bubonic plague To call it a comeback might be strong, but the same Black Death that wiped out millions in Europe has cropped up in the United States, with human cases reported this year in Oregon and Colorado, and a ground squirrel testing positive for plague exposure in California. Between 1,000 and 2,000 cases of plague are still reported worldwide each year. —Alicia P.Q. Wittmeyer
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