Cookiecutter Shark-Related Injuries: A New Threat to Swimming Across the Ka'iwi Channel.

In a 5-month period in 2019, 3 long-distance swimmers sustained cookiecutter shark-related injuries while attempting to cross the Ka'iwi Channel between the Hawaiian Islands of O'ahu and Moloka'i. This report is the first case series of cookiecutter shark bites on live humans. A retrospective review of the State of Hawai'i Division of Aquatic Resources Shark Incidents List was conducted between March 1, 2019, and July 31, 2019. Trauma registry data and medical records were reviewed in patients treated for cookiecutter shark bites at The Queen's Medical Center in Honolulu, Hawai'i. All 3 patients sustained nonfatal cookiecutter shark bite circular wounds measuring between 8-13 cm in diameter. They were injured swimming over waters with depths of greater than 2000 feet at night. Patients had prolonged transport times to the emergency department (ED), averaging 73 minutes, due to their injuries occurring on the open water. All were hemodynamically stable upon ED arrival and did not require blood products. Tetanus toxoid was updated, and prophylactic antibiotic coverage, including doxycycline for Vibrio spp., was administered. Two of 3 patients were treated with operative management. Open water swimmers crossing the deep waters between the Hawaiian Islands at night are most at risk for cookiecutter shark bites. Wounds may penetrate down to and through the fascial level. Immediate life-saving hemorrhage control administered by personnel accompanying the swimmers on the open water is important for preventing morbidity and mortality. Antibiotic prophylaxis for marine bacteria is recommended.