关键词: 疟疾, 近期复发, 动物模型, 食蟹猴疟原虫

Abstract: The present paper reports that the short-term relapse could be artificially made by the application of the experimental method, and thus we established the monkey model of the short-term relapse. According to the experimental design,when the parasitemia was detected in rhesus monkeys infected with sporozoites of Plasmodium cynomolgi, a combined therapy of pyronaridine 6 mg/kg body weight, artemether 10 mg/kg and chloroquine 20 mg/kg once daily for 3 days was carried out to clear the erythrocytic parasite and then the short-term relapse was observed in the animal follow-up for 100 days. The combined therapy was given again when relapse occurred.One onset of relapse occurred on 47 days after therapy in monkey Ml94 infected with sporozoites 11×103. In M195 infected with sporozoites 55×104, relapes occurred for 3 times on 30,37 and 51 days respectively after medication,but during a follow-up period of 200 days,no relapse was shown in M192 and M193 infected with sporozoites 50 and 55×102, respectively.The results showed that the frequency of the short-term relapse was relative to the sporozoites inoculation,and sporozoites less than 11×103 were not suitable for making short-term relapse in animal model. No long term relapse could be seen in all the 4 monkeys until 400 days.Under existing conditions that the relapse was generally explained with hypnozoite assumption, the establishment of animal model of short-term relapse could be tenable. The reasons were:(l) P. cynomolgi from Vietnam,a parasite with the biological characteristic of short-term relapse, was recognized; (2) A series of studies for the relationship between the parasite and monkey host was carried out and the experimental basis of the model establishment was put forward by the authors; (3) This study did not exclude the hypnozoite assumption.The significance of this animal model study at least included : (1) to innovate the treatment countermeasure of the short-term relapse of malaria; (2) to study the biology of the short-term relapse; and (3) to test the antimalarial drugs for the radical cure of vivax malaria. As for the animal model of the long-term relapse,it will be necessary for study to select the monkey parasite which has the biological characteristic of long-term relapse. The verification of the relative problem,hypnozoite assumption,will also be necessary.