Persisting Exo-erythrocytic Cycle in Plasmodium Cynomolgi

Abstract
A monkey (Macaca mulatta) infected with P. cynomolgi developed a characteristic malarial infection, with parasites in the blood for about 2 months. Two months after parasites had disappeared from the blood a liver biopsy revealed 2 bodies, one 16u and the other 30u in diam., which were considered to be exo-erythrocytic forms of P cynomolgi. Shortly after the operation parasites again appeared in the blood. The authors consider that relapses in patients treated for malaria result from the persistence of the exo-erythrocytic stage of the organism in the liver.