Malaria is a disease that spreads via mosquito-borne parasites. It causes fevers, flu-like symptoms, and anemia, and can be fatal if not treated. It has been essentially eradicated from North America, but travelers to malaria-infected parts of the world should take precautions. Forty-one percent of the world's population lives in areas with malaria. Pregnant women are particularly susceptible, and malaria can contribute to low birth weight babies.