Outbreak of human external ophthalmomyiasis due to Oestrus ovis in northwestern Spain: Diagnosis, management, and case series.

INTRODUCTION

To present a case series of external ophthalmomyiasis caused by Oestrus ovis (L. 1758) (Diptera, Oestridae) larvae over an eight-week period in Santiago de Compostela (NW Spain), highlighting its entomology facts, epidemiological factors, clinical management, and possible complications.

METHODS

Five cases were detected at the Ophthalmology Emergency Department of the Hospital Clínico Universitario de Santiago de Compostela. All patients presented with foreign body sensation, tearing, and ocular redness. Larvae were mechanically removed and identified as O. ovis in the L1 larval stage.

RESULTS

Early treatment with larval extraction, antiseptics, and anti-inflammatory agents led to complete resolution without complications. Cases were associated with rural exposure during late summer and early autumn under warm and humid climatic conditions.

CONCLUSION

External ophthalmomyiasis is an uncommon parasitic zoonosis caused by dipteran larvae, with O. ovis being the most common agent. Accurate diagnosis and early treatment prevent complications. This series highlights the importance of considering climatic and rural exposure factors in endemic areas and suggests the potential impact of climate change on the disease's distribution.