The "us-against-them" mindset may take on new meaning when applied to infections by the parasitic protozoan Trypanosoma cruzi. New research shows that bits of foreign DNA from the parasite become integrated into the DNA of an infected person. This is the first time that parasitic DNA has been found in the human genome, says Antonio Teixeira of the University of Brasilia in Brazil.
"This is a very new idea, and as such it will be controversial," says parasitologist David A. Campbell of the University of California, Los Angeles, who was not involved in the study. "It's surprising, but I'm convinced by the data."