Studies on Sporozoite-Induced Infections of Rodent Malaria

III. The Course of Sporozoite-Induced Plasmodium Berghei in Different Hosts

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  • Department of Preventive Medicine, New York University School of Medicine, New York, New York 10016


The course of sporozoite-induced Plasmodium berghei malaria was studied in albino rats, albino mice, golden hamsters, and tree rats (Thamnomys surdaster), a natural host of this parasite. Animals were inoculated with sporozoites obtained by trituration and differential centrifugation of laboratory-bred Anopheles stephensi which 14 days previously had fed on hamsters infected with the NK 1965 strain of P. berghei.

After a uniform dose (25,000 sporozoites injected intraperitoneally) the course of infection was characteristic for each rodent species and with the exception of the mice showed little variation from experiment to experiment.

The injection of smaller inocula (10,000 and 1,000 sporozoites) not only reduced the percentage of infected animals within each species but also delayed the course of the resulting infections. This was generally refected in their longer prepatent periods, delayed onset of parasitemia, and longer survival. Young rats were shown to be the most susceptible animal to sporozoite-induced infection.