Virulence of Trypanosoma cruzi in Açai (Euterpe oleraceae Martius) Pulp following Mild Heat Treatment

ABSTRACT Outbreaks of acute Chagas disease (ACD) in northern Brazil can be caused by the ingestion of unprocessed acai pulp contaminated with Trypanosoma cruzi. The aim of this study was to determine the minimum thermal process required to inactivate T. cruzi in acai pulp. Trypomastigotes (100,000) of T. cruzi Y strain were added to 0.15 M NaCl or acai pulp and continuously mixed while being heat treated at 37 to 49°C for up to 1 h. When necessary, parasites were separated from acai pulp by forced sieving. Inocula were administrated intraperitoneally in inbred immunodeficient C.B-17-Prkdcscid/Pas Unib mice, and the recipients were monitored for parasitemia and mortality. Mice received prophylactic antibiotic therapy by using cephalexin to prevent bacterial infection from the acai pulp. T. cruzi retained its virulence in 0.15 M NaCl and acai pulp at 44 ± 0.1°C for 10 min and at 43 ± 0.1°C for 20 min, respectively, causing ACD and death in mice up to 24 days after infection. Incubation of acai pulp inoculum...