Plasmodium ovale: observations on the parasite development in Saimiri monkey hepatocytes in vivo and in vitro in contrast with its inability to induce parasitemia.

Research paper by P P Millet, C C Nelson, G G GG Galland, J S JS Sullivan, C L CL Morris, B B BB Richardson, W E WE Collins

Indexed on: 01 Jun '94Published on: 01 Jun '94Published in: Experimental Parasitology


Exoerythrocytic stage parasites of the human malaria parasite Plasmodium ovale were cultured in vitro by inoculating primary cultures of hepatocytes from Saimiri sciureus boliviensis monkeys with sporozoites. Morphology and size of the liver stages were similar to previous in vivo descriptions in humans and chimpanzees. Saimiri monkeys did not develop parasitemia after repeated inoculations with P. ovale sporozoites. However, liver-stage parasites were observed in liver biopsies performed 7 days after sporozoite inoculation. Together with observations on other parasite development, these results demonstrate that host specificity for many malaria parasites occurs at the blood-stage level. Lack of host specificity of primary malaria parasite species for the liver forms the basis for the close relationship existing between human and nonhuman primate malaria species.