Plasmodium vivax
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring (Benign tertian) malaria, "P. vivax" is one of the five species of malaria parasites that commonly infect humans. Although it is less virulent than "Plasmodium falciparum", the deadliest of the five human malaria parasites, "P. vivax" malaria infections can lead to severe disease and death, often due to splenomegaly (a pathologically enlarged spleen). "P. vivax" is carried by the female "Anopheles" mosquito; the males do not bite.
History of malaria
Britain's Sir Ronald Ross, an army surgeon working in Secunderabad India, proved in 1897 that malaria is transmitted by mosquitoes, an event now commemorated via World Mosquito Day. He was able to find pigmented malaria parasites in a mosquito that he artificially fed on a malaria patient who had crescents in his blood. He continued his research into malaria by showing that certain mosquito species ("Culex fatigans") transmit malaria to sparrows and he isolated malaria parasites from the salivary glands of mosquitoes that had fed on infected birds. He reported this to the British Medical Association in Edinburgh in 1898.