Risk of Oral Myiasis in Intensive Care Unit: A Case Report Caused by Calliphoridae.

Myiasis is a rare ectoparasitic infestation characterized by the invasion of living tissue by fly larvae of the order Diptera. While larvae typically target wounded skin, ocular, nasopharyngeal, and gastrointestinal regions, oral myiasis is a less frequently reported but clinically significant site of infestation. Herein, we report a case of oral myiasis in a 68-year-old male patient who was intubated and managed in the intensive care unit following a high-altitude fall resulting in a Type III odontoid fracture. A tracheostomy was subsequently performed and during routine replacement of a nasogastric tube, multiple motile larvae were observed in the oral cavity. The larvae were mechanically removed, and the affected area was thoroughly irrigated with a sodium bicarbonate solution. Parasitological examination, including both macroscopic and microscopic analysis, identified the larvae as third-instar forms of the Calliphoridae family. Despite ongoing intensive supportive care, the patient developed sepsis and multiorgan failure, culminating in cardiopulmonary arrest and death. This case suggests that oral myiasis may occur even under strict adherence to standard infection control measures. It highlights the necessity for individualized risk assessment and the implementation of advanced, targeted prevention strategies in vulnerable intensive care unit populations, considering the complex interplay of host, environmental, and systemic factors.