Malaria occurs in nearly 100 countries worldwide, exacting a huge toll on human health and imposing a heavy social and economic burden in developing countries, particularly in Sub-Saharan Africa and South Asia. An estimated 207 million people suffered from the disease in 2012, and about 627,000 died. About 90 percent of the deaths were in Sub-Saharan Africa, and 77 percent were among children under age 5.