The severity depends on which species of the parasite is responsible for the disease. Severe falciparum infection can cause cerebral malaria with seizures, coma, kidney failure and death.
Mixed infections can occur.
Of the four species, Plasmodium falciparum is the most lethal. It is a major cause of illness and death in many tropical and subtropical areas in South America, Southeast Asia and parts of subSaharan Africa. The occurrence of antibiotic-resistant malaria in many parts of the world is a major concern. All reported cases have acquired their infections while travelling abroad. The other parasites infecting humans are more benign.