Plasmodium falciparum is a protozoan parasite, one of the species of Plasmodium that cause malaria in humans. It is transmitted by the female Anopheles mosquito. Malaria caused by this species (also called malignant or falciparum malaria) is the most dangerous form of malaria, with the highest rates of complications and mortality. As of the latest World Health Organization report in 2015, there were 214 million cases of malaria worldwide. This resulted in an estimated 438,000 deaths. Rates of infection have decreased from 2000 to 2015 by 37%, but increased from 2014 during which there were 198 million cases. It is much more prevalent in sub-Saharan Africa than in many other regions of the world; in most African countries, over 75% of cases were due to P. falciparum, whereas in most other countries with malaria transmission, other, less virulent plasmodial species predominate. Almost every malarial death is caused by P. falciparum.