A 35-year-old man comes to the physician for evaluation of irritation in the left eye. He returned from a trip to the Ivory Coast 3 months ago. Temperature is 37.0°C (98.6°F),
blood pressure is 115/83 mmHg, and
pulse is 79/min. On physical examination, the left eyelid appears swollen. Slit-lamp examination reveals a transparent worm in the conjunctiva of the left eye. Which of the following is the most likely mode of transmission of this worm to the patient?