Dr. Michelle Barron, medical director of infection prevention and control at UCHealth University of Colorado Hospital [and CU School of Medicine], received an unusual call last month from the microbiology lab: Confirmation of the third case this year of trench fever, a rare condition transmitted by body lice that plagued soldiers during World War I. Barron’s epidemiological training kicked in. “Two is always an outbreak, and then when we found a third — OK, we clearly have something going on,” Barron recalled thinking.