TABLE 1.

Tissue parasitism in the chronic phase of T. cruzi infection^a

Mouse group	% Parasitized samples (no. parasitized/total no. examined)
	Heart	Liver	Striated muscle	Blood
With tissue nestsb
A/J	0 (0/24)	0 (0/24)	4.8 (1/21)
C3H	13.0 (3/23)	0 (0/23)	0 (0/20)
With positive LIT culturesc
A/J	0 (0/14)	0 (0/14)	NDd	28.6 (4/14)
C3H	38.5 (5/13)	0 (0/13)	ND	38.5 (5/13)

^aAt the time of sacrifice, all C3H/HePAS and A/J chronically infected mice displayed positive serology for Sylvio X10/4 parasite antigen.

^bParasite nests were observed by optical microscopy in tissue sections stained with hematoxylin-eosin.

^cTissue parasites were evaluated by culture of tissue homogenate aliquots in LIT medium, as described in Materials and Methods.

^dND, not done.