Prevention

Prevention is achieved with improved sanitation, especially good water and sewer systems and proper washing of fruits, vegetables, and hands. Routine chlorination of water does not destroy cysts. A Brazil­ian root, ipecacuanha, and its active ingredient, emetine, have been given orally to treat dysentery since the seventeenth century. It was first given by injection in 1912 and, despite its toxicity, is some­times still employed for both intestinal and ex- traintestinal amebiasis. Safer drugs, such as metro­nidazole, are usually employed but must be given over 10- to 20-day periods and relapses are frequent. Infection does not produce immunologic protection against reinfection with the same or another strain.