This is a hookworm egg. Hookworms hatch in damp vegetation. Their larvae can enter the human body through the skin, even without cuts or abrasions. Once through the skin, they begin the next step of their life cycle.
Review Date 9/1/2021
Updated by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.