Baylisascariasis By Chelsea Marie, PhD, University of Virginia; William A Petri, Jr, MD, PhD, University of Virginia School of Medicine Reviewed / Revised Sep 2022 View Patient Education Diagnosis Treatment Prevention Key Points Baylisascariasis is a rare infection with the raccoon ascarid, Baylisascaris procyonis, which may cause fatal central nervous system (CNS) infection, ocular disease, or a visceral larva migrans syndrome in humans.