Parasitic diseases are the foremost worldwide health problem today, particularly in the under developed countries. It is estimated that the global prevalence of some of these diseases already exceeds 60% among the more than three billion people living in parasite endemic areas. Parasitic diseases are not confined to humans but also affect many domestic and wild animals causing an enormous economical blight to already poor countries and societies. In spite of the present alarming health and economic proportions of parasitic infections, these diseases are still on the rise largely because of poor sanitation and health education, inadequate control of measures, greater use of irrigation for agricultural development, increase and redistribution of world population, increased world travel, and development of resistance to drugs used for chemotherapy or control of vectors. In addition, with the recent advent of AIDS, several parasitic diseases which previously did not constitute a major threat to human health