List of Plasmodium species infecting primates

The Plasmodium species infecting primates include the parasites causing malaria in humans.
Species infecting humans.
Rare cases.
While infection of humans by other species is known, they are quite rare, in some instances, only a single case. In a number of the cases, the means of infection is unknown, and may be due to accident, i.e. infection by laboratory equipment or a bite by an animal. With the use of the polymerase chain reaction additional species have been and are still being identified that infect humans.
One possible experimental infection has been reported with "Plasmodium eylesi". Fever and low grade parasitemia were apparent at 15 days. The volunteer (Dr Bennett) had previously been infected by "Plasmodium cynomolgi" and the infection was not transferable to a gibbon ("P. eylesi" 's natural host) so this cannot be regarded as definitive evidence of its ability to infect humans. A second case has been reported that may have been a case of "P. eylesi" but the author was not certain of the infecting species.
A possible infection with "Plasmodium tenue" has been reported. This report described a case of malaria in a three-year-old black girl from Georgia, United States, who had never been outside the US. She suffered from both "P. falciparum" and "P. vivax" malaria and while forms similar to those described for "P. tenue" were found in her blood even the author was skeptical about the validity of the diagnosis.
Confusingly "Plasmodium tenue" was proposed in the same year (1914) for a species found in birds. The human species is now considered to be likely to have been a misdiagnosis and the bird species is described on the "Plasmodium tenue" page.
Former names.
Taxonomy in parasitology until the advent of DNA based methods has always been a problem and revisions in this area are continuing. A number of synonyms have been given for the species infecting humans that are no longer recognised as valid. Since perusal of the older literature may be confusing some currently defunct species names are listed here.
"Plasmodium shortii" and "Plasmodium osmaniae" are now considered to be junior synonyms of "Plasmodium inui".
Notes.
Until recently the only known host of "P. falciparum" was humans but this species has also been described in gorillas ("Gorilla gorilla") and bonobos There has been a single report of "P. falciparum" in a brown howler monkey ("Alouatta guariba") and in black howler monkeys ("Alouatta caraya") but until this is confirmed its validity should be considered dubious.
A possible report of "P. falciparum" in a greater spot-nosed monkeys ("Cercopithecus nictitans") has not been confirmed in a large survey.
A species that clusters with "P. falciparum" and "P. reichenowi" has been identified in Gabon, Africa in chimpanzees ("Pan troglodytes"). This appears to have diverged from these two species about 21 million years ago. It has only been identified from the sequence of its mitochondrion to date and further work is needed to characterise the species. A second report has confirmed the existence of this species in chimpanzees. A third report has confirmed the existence of this species.
Night monkeys ("Aotus nigriceps") can be infected with "P. falciparum". This infection may occur naturally. Their potential role - if any - as a source of human infection is unknown.
Two additional species within the subgenus "Laverania" have been identified on the basis of DNA sequences alone: "Plasmodium billbrayi" and "Plasmodium billcollinsi". and bonobos "P. billbrayi" was found in two subspecies of chimpanzee ("Pan troglodytes troglodytes" and "Pan troglodytes schweinfurthii"). "P. billcollinsi" was found in only one subspecies of chimpanzee ("Pan troglodytes troglodytes"). Further work is needed to characterise these species.
Humans are currently considered to be the only host for "P. malariae". However Rodhain and Dellaert in the 1940s showed with transmission studies that "P. malariae" was present in chimpanzees.
The presence of "P. malaria" in chimpanzees has been reported in Japan suggesting that this species may be able to act as a host. A second paper has described the presence of "P. malaria" in wild chimpanzees. Another paper has reported several cases of "P. malariae" in brown howler monkey ("Alouatta guariba") and black howler monkeys ("Alouatta caraya") It has been shown that splectomised three-striped night monkey ("Aotus trivirgatus") can be infected with "P. malariae". Another paper has confirmed the presence of "P. malaria" in chimpanzees.
The existence of multiple independent reports seem to suggest that the chimpanzee and possibly other species may act as a host to "P. malaria" at least occasionally.
"P. vivax" will infect chimpanzees. Infection tends to be low grade but may be persistent and remain as source of parasites for humans for some time. "P. vivax" is also known to infect orangutans and the brown howler monkey ("Alouatta guariba clamitans") "P. vivax" has been reported from chimpanzees living in the wild. It has been suggested that "vivax" infection of the great apes in Africa may act as a reservoir given the prevalence of Duffy antigen negative humans in this area.
Like "P. vivax", "P. ovale" has been shown to be transmittable to chimpanzees. "P. ovale" has an unusual distribution pattern being found in Africa, Myanmar the Philippines and New Guinea. In spite of its admittedly poor transmission to chimpanzees given its discontigous spread, it is suspected that "P. ovale" may in fact be a zooenosis with an as yet unidentified host. If this is actually the case, the host seems likely to be a primate. A report has been published suggesting that "P. ovale" may be a natural parasite of chimpanzees but this needs confirmation. "P. ovale" has since been described from chimpanzees living in the wild. This suggests that human infection with this species may as previously suspected be a zoonosis.
It has been recently shown that "P. ovale" is actually two genetically distinct species that coexist. These species are "Plasmodium ovale curtisi" and "Plasmodium ovale wallikeri". These two species separated between 1.0 and 3.5 million years ago.
"Plasmodium knowlesi" has a natural reservoir in the macaques of Southeast Asia, and was only in 1965 identified as being transmissible to humans.
The remaining species capable of infecting humans all have other primate hosts.
"Plasmodium" taxonomy.
Interrelatedness - The evolution of these species is still being worked out and the relationships given here should be regarded as tentative. This grouping, while originally made on morphological grounds, now has considerable support at the DNA level.
Subspecies.
Many species of "Plasmodium" which infect primates have been divided into subspecies. Examples are listed below:
Species infecting other hosts.
Most if not all "Plasmodium" species infect more than one host: the host records shown here should be regarded as incomplete.
It has been proposed that the species "P. gora" and "P. gorb" should be renamed "P. adleri" and "P. blacklocki" respectively.
Primate groups and Plasmodium species.
New World monkeys of the family Cebidae: "P. brasilianum" and "P. simium"
Old World monkeys of the family Cercopithecidae: "P. coatneyi", "P. cynomolgi", "P. fieldi", "P. fragile", "P.gonderi", "P. georgesi", "P. inui", "P. knowlesi", "P. petersi", "P. shortti" and "P. simiovale"
Gibbons of the family Hylobatidae: "P. eylesi", "P. hylobati", "P. jefferyi" and "P. youngi"
Orangutans ("Pongo"): "P. pitheci" and "P. silvaticum"
Gorillas and chimpanzees: "P. billcollini", "P. billbrayii", "P. falciparum", "P. gabonensi", "P. gora", "P. gorb", "P. reichenowi", "P. rodhaini" and "P. schwetzi"
Mosquitoes known to transmit human malaria listed by region.
This listing may be incomplete as the taxonomy of this genus is under revision.
North American
Central American
South American
North Eurasian
Mediterranean
Afro-Arabian
Afrotropical
Indo-Iranian
Indo-Chinese hills
Malaysian
Chinese
Australasian