Did you know that micro-organisms can live in blood? Plasmodium parasites can infect red blood cells and cause a serious disease called malaria. This disease is mostly seen in young children living in Africa. Sick children have a fever, aches, can feel very tired, and in bad cases, they can even die from malaria. There are medicines that cure malaria, but it is hard to get these to everyone who needs them. Fortunately, as children grow older, they do not feel as sick when they are infected by the malaria-causing parasite. Better yet, adults hardly ever get malaria. The reason for this difference between children and adults has to do with how well the body's defense system can fight off the parasite. Keep reading if you want to learn more about malaria, the Plasmodium parasite and how the immune system fights against it.