She remembered dislodging a fly from her ear while in Peru but thought nothing more of it until she started getting headaches and pains down one side of her face and woke up in Britain one morning with liquid on her pillow.
Thinking she had a routine ear infection caused by a mosquito bite, she sought medical treatment at the Royal Derby Hospital in northern England, where a consultant noticed worms in a small hole in her ear-canal.
Doctors tried first to flush the worms out of the ear using olive oil. When flushing the worms out failed, the medics resorted to surgery and found a "writhing mass of worms" within her ear, raising concern they could eat into her brain.
The surgery removed a family of eight worms.
The worms that Harris, 27, was hosting were the larvae of the New World screwworm fly (Cochliomyia hominivorax). The fly is a notorious livestock pest that also seeks out pets, zoo animals and occasionally humans as hosts.