Guinea worm disease is not curable, but it is easily preventable. The most effective method is teaching villagers in Asia and Africa how to filter their drinking water through a tightly woven cloth developed and donated by DuPont and manufactured by Precision Fabrics Group of Greensboro, N.C. The cloth is distributed to villagers who make water filters for individual households. There were more than 3.2 million reported cases of the disease in 1986. By 2011, that number had dropped to 1,060, according to the World Health Organization.