Oroya Fever and Verruga Peruana (Carrión Disease) By Larry M Bush, MD, FACP, Charles E Schmidt College of Medicine, Florida Atlantic University; Maria T Vazquez-Pertejo, MD, FACP, Wellington Regional Medical Center Reviewed / Revised Apr 2022 | Modified Sep 2022 View Patient Education Oroya fever and verruga peruana are infections caused by the gram-negative bacterium Bartonella bacilliformis.