Reversibility of muscle and heart lesions in chronic Trypanosoma cruzi infected mice after late trypanomicidal treatment

Abstract

The effect of trypanomicidal treatment upon established histopathological Trypanosoma cruzi induced lesions was studied in Swiss mice. The animals were inoculated with 50 trypomastigotes and infection was allowed to progress without treatment for 99 days. After this period, the animals were divided in three groups, treated for 30 days with either placebo, benznidazole (200 mg/kg/day) or nifurtimox (100 mg/kg/day). These treatments induced 94 and 100% cure rates respectively as detected by xenodiagnosis and reduction of antibody levels. Autopsies and histopathological studies of heart, urinary bladder and skeletal muscle performed on day 312 after infection showed almost complete healing without residual lesions. As long periods were allowed between infection, treatment and autopsy, the results indicate that tissue lesions depend, up to advances stages, on the continuous presence of the parasite.

Chagas disease: criteria of cure and prognosis

“…Regarding the role of the parasite in maintaining the inflammatory process in the chronic phase, recent studies by Kalil et al (1993) and Higushi (1995) confirm the historic studies of Chagas and Torres and the results of experimental research by Segura et al (1994) and Andrade et al (1991). The latter has brought new hope to clinicians because they reported the interruption of the progression of lesions in treated mice, and verified the effect of benznidazole in the regression of myocardial inflammatory lesions and in skeletal muscle of chronically infected animals that presented parasitologic cure even though serologic tests were positive.…”

Benznidazole Treatment following AcuteTrypanosoma cruziInfection Triggers CD8+T-Cell Expansion and Promotes Resistance to Reinfection

“…This nitro derivative is known to reduce the level of parasitism and eliminate the acute-phase symptoms, thus abbreviating the course of infection (for a review, see reference 10). However, the efficiency of anti-T. cruzi therapy in the chronic phase is still controversial (4,10,16,34).…”

Seroprevalence of Chagas disease in schoolchildren from two municipalities of Jequitinhonha Valley, Minas Gerais, Brazil; six years following the onset of epidemiological surveillance

“…However, one of the infected children showed an enlarged Pri, which could be an early and transient ECG Chagasic alteration, frequently found in chagasic children during and after the acute phase of the infection 13,23,26 . Similar findings were previously reported regarding the high prevalence of early ECG abnormalities in T. cruzi infected children 3 .…”

“…Further periodical clinical and laboratorial evaluations after treatment will be performed aiming to verify the parasitological cure and the impact of chemotherapy on the evolution of the disease. Considering the age of the individuals and the genetic of the parasite detected in the area, mainly T. cruzi II isolates 11 , the expectative of the authors is optimist since the benefit effects of chemotherapy can be better in young people or recent infections in both cure 2,6,29 and prognosis of the infection 5,26,28,30 .…”