Chronic experimental infection by Trypanosoma cruzi in Cebus apella monkeys

Abstract

Twenty young male Cebus apella monkeys were infected with CA1 Trypanosoma cruzi strain and reinfected with CA1 or Tulahuen T. cruzi strains, with different doses and parasite source. Subpatent parasitemia was usually demonstrated in acute and chronic phases. Patent parasitemia was evident in one monkey in the acute phase and in four of them in the chronic phase after re-inoculations with high doses of CA1 strain. Serological conversion was observed in all monkeys; titers were low, regardless of the methods used to investigate anti-T. cruzi specific antibodies. Higher titers were induced only when re-inoculations were performed with the virulent Tulahuén strain or high doses of CA1 strain. Clinical, electrocardiographic and ajmaline test evaluations did not reveal changes between infected and control monkeys. Histopathologically, cardiac lesions were always characterized by focal or multifocal mononuclear infiltrates and/or isolated fibrosis, as seen during the acute and chronic phases; neither amastigote nests nor active inflammation and fibrogenic processes characteristic of human acute and chronic myocarditis respectively, were observed. These morphological aspects more closely resemble those found in the "indeterminate phase" and contrast with the more diffuse and progressive pattern of the human chagasic chronic myocarditis. All monkeys survived and no mortality was observed.

First report of Sapajus cay naturally infected by Trypanosoma cruzi in San Pedro Department, Paraguay

“…apella is highly susceptible to T. cruzi infection and has been used as a model for experimental infections, being able to maintain parasitemia during long-term infection, with low level of severe symptoms that characterized Chagas disease in humans and without mortality (ALMEIDA et al, 1992;RIARTE et al, 1995). Long-lasting natural infection was also observed in L. rosalia (golden lion Tamarin) specimens, which after ten-year follow-up were able to maintain high parasitemias (LISBOA et al, 2015).…”

Chronic Chagas’ Disease in Rhesus Monkeys (Macaca Mulatta): Evaluation of Parasitemia, Serology, Electrocardiography, Echocardiography, and Radiology

“…[54][55][56][57][58][59][60][61][62][63][64] Electrocardiographic abnormalities, suggesting the presence of acute T. cruzi-elicited myocarditis, have been described in Cebus apella and Saimiri sciureus. 44,[65][66][67][68][69][70] In fact, our animals presented several ECG abnormalities attributed to the presence of the parasite in the cardiac tissue from the fourth week of infection up to the 12th week of the acute phase. 13 Moreover, after 17 years of infection, the ECG abnormalities in monkeys 90, 95, and 103 may have been due to T. cruzielicited myocardial damage, while the alterations observed in monkeys 42 and 64 were transitory and isolated, consequently without diagnostic significance, suggesting that these animals had the indeterminate form of chronic Chagas' disease.…”

Reservoir host competence and the role of domestic and commensal hosts in the transmission of Trypanosoma cruzi

“…Comparison of the age-specific infectiousness of T. cruzi-seropositive dogs before and 1-2 years after suppression of domestic bug infestations revealed insignificant differences over time (Gürtler et al, 1992b). Similarly, the experimental effects of reinoculations on infectiousness in dogs, monkeys and mice were also slight and transient or nil (Andrade et al, 2006;Bustamante et al, 2007;Machado et al, 2001;Riarte et al, 1995). However, when dogs were inoculated successively with two stocks of T. cruzi, both genotypes were recovered from three out of eight dogs and one of the genotypes predominated during the follow-up (Machado et al, 2001).…”