Ophthalmomyiasis Externa and Importance of Global Warming: A Case Report by Lucilia sericata and Review of the Medical Literature
Authors: Martínez-Rojano Hugo , Huerta Heron , Samano Reyna , Chico-Barba Gabriela , Mier-Cabrera Jennifer , Plascencia-Nieto Estebiyesbo Said 
Published: August 2023

Myiasis is a medical condition in humans caused by the larvae and worms of certain types of flies, specifically the Sarcophagidea species. If this parasitic infection occurs in the external part of the eye, it is known as external ophthalmomyiasis. This condition is more commonly found in the Mediterranean and the Near East and is rare in North America.
Objective: This report and review aim to describe and compare the risk factors, clinical course, and parasitologic features of external ophthalmomyiasis. We also discuss the different preventive measures in a large case series reported from January 2000 to December 2022. Methods: We report the first case of external ophthalmomyiasis in Mexico caused by Lucilia sericata in an adolescent with no clinical risk factors. Additionally, we perform a literature review of reported cases of external ophthalmomyiasis to determine the clinical characteristics, therapeutic management, and information on the organisms that most commonly cause external ophthalmomyiasis. Results: A total of 312 cases of external ophthalmomyiasis were recorded, with 208 cases in males (66.7%) and 102 cases in females (32.7%). In two cases, the gender and species responsible for the ophthalmomyiasis were not reported (0.6%). The mean age of those affected was 32.1 ± 18.5 years, ranging from newborns to 91 years old. The male-to-female ratio was 2:1. The most common causative organism was Oestrus ovis, accounting for 72.1% of cases, followed by Dermatobia hominis at 5.4%, Lucilia sericata at 0.96%, and Chrysomyia bezziana at 0.96%. Before experiencing symptoms, 43.6% of cases reported having direct contact with flies or being hit in the eye, 33% reported no associated risk factors, 9.3% reported living with sheep and goats, and 7.7% reported a history of foreign objects entering the eye. The most common symptoms for those affected by Oestrus ovis were sudden onset, including a foreign body sensation and movement, redness, tearing, itching, swelling, irritation, photophobia, burning, and ocular secretion. In cases caused by Dermatobia hominis, symptoms included eyelid edema, pain, redness, itching, movement within the lesion, ocular irritation, and discharge. Regarding occupational or recreational activity, agriculture and livestock had the highest incidence, followed by trades and technical activities, being a student, and having traveled to an endemic region for work or recreation. Conclusion: Patients with red eyes may suffer from external ophthalmomyiasis, which requires a thorough examination to diagnose and treat it early. Moreover, as the temperature increases due to climate change, it is essential to consider how this will affect the spread of different pathogens. Specifically, the life cycle of Oestrus ovis is greatly influenced by temperature, which suggests that the incidence of ophthalmomyiasis will rise with warmer temperatures.