FIG. 1.

T. cruzi first infects and replicates in local tissues, followed by systemic dissemination. A total of 56 mice were studied by immunohistochemistry and/or real-time PCR. Early after challenge (days 3 to 5) parasites were detected only in the nasolacrimal ducts and nasal cavity (NLD/NC, white bars) and draining lymph nodes (LN, gray bars). Only 9 to 11 days after infection can significant numbers of parasites be detected in more distant tissues such as the spleen (SP, black bars). The number of mice in which evidence of infection was detected is shown in the numerator of each bar while the total number of mice studied is shown in the denominator.