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.