Chagas is transmitted by bugs that excrete while feeding. N. American bugs do not excrete while feeding but there is the possibility that the trypanosome will alter bug behavior - S. American bugs are bolder feeders, prefer the face of humans, and excrete while eating.
Ticks transmit disease by regurgitating into the host’s bloodstream - not much benefit in that for the tick - benefit for the bacteria or protozoa.
Toxoplasmosis changes mouse behavior and quite possibly human behavior and there are a number of weird infections that completely override insect behavior.
All that said, since new infections are decreasing even in the tropics and are associated with thatched roofs and dirt floors, there’s not much likelihood of Chagas becoming a major concern here except for already infected immigrants.
Fascinating. I thought that all those little black blobs around a tick bite on my dog they were tick poop. So are they dried regurgitated blood?