Abstract:

A well-cared-for, bedridden, and helpless 94-year-old female resident in a Tennessee nursing home experienced sudden, rapid weight loss, severe lethargy, and increasingly foul-smelling bed sores between late February and April 2022. By April 5, her modern, climate-controlled room became infested with small flies, initially identified as “gnats” by staff. Despite immediate pest control measures—removal of plants and food, spraying, sealing drains, and deploying insect traps—the infestation intensified, with hundreds of tiny flies spreading to other rooms by April 12. By April 13, the facility administration, out of options, considered isolating the patient. On April 14, her family identified the flies as parasitoid scuttle flies, Megaselia scalaris (Lowe, 1866) (Diptera: Phoridae), a species capable of human myiasis.

Following a literature review, a simple treatment protocol by Sayeed et al. (1) was administered on April 15 and 16, resulting in the complete elimination of M. scalaris within 3 days. The patient subsequently lived an additional 7 months with improved quality of life, awareness, appetite, and comfort, without further weight loss, progression of bedsores, or visible insect presence. Zevo insect traps remained in place for monitoring, and the patient received weekly ivermectin prophylaxis against further phorid myiasis and COVID-19, which was prevalent in the facility. Awareness of M. scalaris myiasis in vulnerable patients and effective treatment protocols remains limited among healthcare personnel across much of the United States.

Keywords: Ivermectin, phorids, Megaselia scalaris, parasitoid, scuttle flies, gnats, elderly, incapacitated, fly larvae.