Caracterização do Calomys callosus como modelo experimental para o estudo da malária

Abstract

Malaria is an infectious parasitic disease caused by the protozoan Plasmodium spp., transmitted by the female Anopheles mosquito. Symptoms vary according to the Plasmodium species and the age of the infected individual, who may remain asymptomatic or progress to severe forms of the disease, such as cerebral malaria. Although several studies involve malarial anemia and BALB/c mice, its pathogenesis regarding the use of these animals is not yet fully elucidated. Calomys callosus rodents have been used as experimental models for the study of parasitic diseases such as Trypanosoma cruzi, Toxoplasma gondii, and Schistosoma mansoni. Therefore, the aim of this study is to investigate the possibility of establishing a new experimental animal model to study the mechanisms of malaria pathogenesis using C. callosus rodents. During the experiment, the animals were infected with Plasmodium berghei ANKA at different doses and evaluated for parasitemia, morbidity score, and body weight. Additionally, the infected animals were later euthanized for the collection of material for hematological analyses. The results obtained revealed that animals infected with 1x10⁷ parasitized red blood cells showed higher parasitemia levels compared to the other dosage groups. Moreover, in the 1x10⁷ dose groups, the parameters of gait, grooming, balance, and weight were altered. Hematological analyses in the 1x10⁷ groups showed neutrophilia, thrombocytopenia, anisocytosis, and a more pronounced reduction in hematocrit compared to the other groups. The survival curve indicated lower survival rates in the groups infected with 1x10⁷. These results demonstrate the effectiveness of the experimental model used and highlight its potential for future research. However, further studies are necessary to confirm these findings and to investigate other variables related to the course of infection.