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.
Plasmodium knowlesi
"Plasmodium knowlesi" is the sixth major human malaria parasite (following the division of "Plasmodium ovale" into 2 subspecies). It may cause severe malaria as indicated by its asexual erythrocytic cycle of about 24 hours, with an associated fever that typically occurs at the same frequency (i.e. the fever is quotidian). This is an emerging infection that was reported for the first time in humans in 1965. It accounts for up to 70% of malaria cases in certain areas in South East Asia where it is mostly found. This parasite is transmitted by the bite of an "Anopheles" mosquito. "Plasmodium knowlesi" has health, social and economic consequences for the regions affected by it.