Case series of Airway Myiasis with maggots, in the Intensive care unit
S. Young, M. Slattery, Ed Major Critical Care Unit, Morriston Hospital, ABM University Trust, Swansea
Morriston Intensive care unit is large mixed level 3 and 2 unit in Morriston Hospital Swansea catering for Medical and surgical patients. There are separate Cardiac and Burns units. It comprises of five sub units with a total of 28 beds.
In the early summer of 2017 the unit became extremely warm, as a result the windows were opened to allow a breeze. This unfortunately let some flies into the unit. They were ignored and not thought to be an issue however they were occasionally seen close to the patients.
The Calliphora is the common blue bottle fly that develops from a few days from larvae to cocoons while growing as a maggot. The larvae are laid by fully grown flies that lay eggs where they feed and are attracted by smell such as decaying or rotting meat. The life cycle in demonstrated in figure 1. According to the life cycle the maggots have a very short life, there are three larval stages that develop from the egg. The first larval stage is 27 hours, the second 22 hours and the third 130 hours. The maggots observed were first seen in the 1st stage and then removed while in the second stage.This species of maggot is commonly used in the treatment of wound infections. They have unique properties in this respect:
The maggots are not invasive and do not feast on healthy flesh but debride necrotic tissue leaving a clean wound.The maggots themselves secrets substances that resist the growth of bacteria most notably MRSA, the only bacteria that they cannot tolerate is Pseudomonas