Malaria is a disease that kills up to 3 million people every year, most of which are children in sub-Saharan Africa. More than 50 percent of the world's population is exposed to the disease, and there are an estimated 300-500 million episodes of acute illness every year. Malaria has been recognized as having a deleterious economic effect by increasing mortality rates (and subsequently encouraging parents to have many children), discouraging investment in malarious areas, and limiting labor force productivity due to frequent bouts of disease. The disease is caused by a single-cell parasite called the plasmodium, which is transmitted from human to human by the female anopheles mosquito. The plasmodium invades and reproduces inside red blood cells, destroying the cells in the process and eventually causing anemia, hemorragic effects and often fatal cerebral malaria. Interestingly, malaria is regulated to a large extent by ecology. First, the mosquito's larval stage requires ponds of water, which means that a minimum level of precipitation is required or the life cycle will be broken. Second, the plasmodium's life cycle is regulated by temperature. The higher the temperature, the faster the plasmodium develops in the mosquito's gut. When temperatures are too low, the plasmodium's development requires a period longer than the mosquito's lifespan, thus preventing transmission.

In the MV Sim, your family members are more likely to contract malaria at lower levels of health or when not sleeping under a bednet at home. In addition, your family members are more likely to contract malaria when transmission in the village is high.