Acute Chagas' disease in non-human primates. 1. Chronology of clinical events, clinical chemistry, ECG, radiology, parasitemia, and immunological parameters in the Cebus apella monkey

Abstract

Forty Cebus apella monkeys free from Chagas' disease were subcutaneously infected with 3 x 10(5) trypomastigotes of the Ypsilon strain of T. cruzi and followed-up for 6 months. Seventeen monkeys were controls. Body weight, temperature, direct parasitemia (DP), IgM and IgG were determined weekly. Hematology was performed weekly up to day 40 p.i. and monthly thereafter. Clinical chemistry was performed every two weeks up to day 33 p.i. and monthly thereafter. ECG was performed weekly up to day 47 p.i. and at 2,3, and 6 months p.i. Chest X-ray was done at 45 days, 4 and 6 months p.i. Xenodiagnosis was only performed after two negative DP. All infected monkeys developed fever, beginning 6.0 +/- 0.6 day p.i. and lasting 21.9 +/- 6.7 days, and lost 14% of their body weight the first month, 11% the third month and 7% the 6th month. DP was already detected 4.4 +/- 0.29 days after infection and it was detectable in all monkeys up to 96.0 +/- 6.9 days p.i. Cyclical peaks of parasitemia were observed throughout the study. IgM and IgG titers which permitted a diagnosis of T. cruzi infection occurred at 33.0 +/- 2.9 days p.i., respectively. Fifty-seven percent of infected monkeys presented ECG alterations one week after inoculation reaching a maximum of 86% at the third week. A normocytic, normochromic anemia was observed in all monkeys being significantly (p less than 0.02) more severe in the infected animals. No effects of T. cruzi on the clinical chemistry were observed.(ABSTRACT TRUNCATED AT 250 WORDS)