Entopolypoides macaci Mayer, 1934 in the African Baboon (Papio cynocephalus L. 1766)

Abstract

Entopolypoides macaci occurs in different populations of Papio cynocephalus in Kenya, but not in the same host with Hepatocystis kochi. Parasitemia may be greatly enhanced by splenectomy, but there is little effect on the host in spite of substantial alteration in hemoglobin and RBC counts, and transferability to other primates is erratic. Descriptions are presented for differentiation of E. macaci from H. kochi.

Detection of Enzootic Babesiosis in Baboons (Papio cynocephalus) and Phylogenetic Evidence Supporting Synonymy of the GeneraEntopolypoidesandBabesia

“…The finding of 31% of baboons overall infected with PB-1 on the basis of blood smear evaluations and the presence of the parasite in animals born and raised in three different geographic locations, including 12% of those directly imported from Africa, points to the origin of the parasite in the animals' ancestral homelands, with continued, effective, transmission occurring in breeding colonies in North America. This is consistent with the findings of Moore and Kuntz, who found 13% of baboons surveyed in central Kenya positive for E. macaci (24). While this preliminary epidemiological data does not permit us to more specifically address what mechanisms of transmission may be involved, either horizontal (mechanical or vectoral) transmission, vertical (maternal-fetal) transmission, or a combination of the two is possible.…”

“…Subsequently, Kuntz and Moore found feral baboons in Kenya infected with a small, intraerythrocytic parasite which they also called E. macaci (21). In most naturally occurring Entopolypoides infections, parasitemias remained low and pathogenic effects were slight or unnoticeable unless the animal had undergone splenectomy, in which case high parasitemias usually did result but, again, with few apparent side effects (8,12,13,16,24). These published clinical observations of African and Asian primates closely parallel our experiences with baboon infections.…”

“…Throughout the course of this recrudescence, the animal displayed no overt ill effects, although it became profoundly anemic and displayed clinical pallor. The variety of parasitic forms seen among the one splenectomized baboon and the other chronically infected baboons was most consistent with that described for E. macaci, reported to naturally infect Macaca irus, Macaca mulatta, Macaca fascicularis, Cercopithecus spp., and P. cynocephalus (8,12,13,23,24,26).…”

“…erythrocytes were found to be infected with typical Babesia-like organisms. Both baboons received blood transfusions from two donors, one of which was shown to be parasitemic, with very rare and delicate intracellular hematozoa most suggestive of Entopolypoides macaci, a Babesia-related parasite described in African and Asian nonhuman primates and, rarely, in humans (8,12,13,23,24,26). Detection of these parasites in animals with intact and abrogated immune systems raised important questions regarding their characterization and origins, whether they represented variants of the same species, their prevalences in colony animals, and mechanisms of transmission.…”

The Pathoparasitology of Nonhuman Primates: A Review

“…The second babesia-like organism, Entopolypoides macaci, is a mildly pathogenic hemosporozoal parasite that has been described in Old World monkeys (cynomolgus monkeys, rhesus monkeys, baboons, and guenons) and great apes (chimpanzees) [32,269,290,332,363,564,565,596,791]. This organism does not have true pyriform stages, but early ring-shaped stages and ameboid stages with polypoid projections of cytoplasm similar to the true Babesia species have been seen.…”