These mosquitoes are present in the tropics and subtropics in almost all countries.
Malaria is the most deadly of all tropical parasitic diseases.
After the parasites enter the body by a mosquito bite, they disappear from the circulating blood within an hour, and gather in the liver. Generally, only falciparum malaria is potentially life-threatening. Patients with severe falciparum malaria may develop liver and kidney failure, convulsions, and coma. Infections with P. vivax and P. ovale may cause less serious illness, but the parasites can remain dormant in the liver for many months, causing a reappearance of symptoms months, or even years, later. Early stages of malaria may be similar to the flu.