According to the Centers for Disease Control and Prevention (CDC), myiasis is infection with a fly larva, usually occurring in tropical and subtropical areas.
There are a number of ways to contract it–getting an infection from accidentally ingesting larvae, from having an open wound or sore, or through your nose or ears. People can also be bitten by mosquitoes, ticks, or other flies that harbor larvae. In tropical areas, where the infection is most likely to occur, some flies lay their eggs on drying clothes that are hung outside.
In Hong Kong, health officials reported two human myiasis cases in late January and early February.
The first case affected a 99-year-old elderly home resident. She was bedbound with multiple medical illnesses and was on Ryle’s tube feeding. She presented with gum swelling and bleeding on January 15, and was admitted to a public hospital the next day. Surgical examination found a large oral ulcer with deep cavity and maggots in wound. The maggots were confirmed to be Chrysomya bezziana. Her condition remained stable and she was discharged on January 22. Advice on oral care for Ryle’s tube fed residents and environmental hygiene were given to the elderly home.
The second case affected a 68-year-old woman with multiple medical illnesses. She had a chronic wound in her left leg for three to four years. She was noted to have increased pain, swelling and discharge of the wound on January 15 and was admitted to a public hospital on January 31. Excision debridement was performed and revealed maggots in the wound. The maggots were confirmed to be Chrysomya bezziana. Her clinical condition remained stable and she was currently hospitalized. Health advice on environmental and personal hygiene and fly proofing measures were given to the patient’s family.