A tropical disease, marked by severe chills and fever, caused by a microscopic parasite called Plasmodium carried by mosquitoes and introduced into the human bloodstream through the mosquito’s bite. The parasites invade the red blood cells and multiple, eventually causing the cells to burst. Symptoms include severe, regularly recurring bouts of fever and prostration. After repeated attacks of malaria, a person will develop anemia and the liver and spleen will become enlarged. Quinine was once the only drug available for treatment but today new, more effective drugs have been developed to prevent and treat the disease. While the malaria mosquito is confined to certain regions of the world, it is important for travelers who intend visiting such places to take a course of preventative drugs.