Clean wounds by acting the maggot

Maggot therapy is used to treat a variety of conditions including pressure sores, surgical wounds and trauma injuries, writes JILL NESBITT

MANY filmgoers will have recoiled at the sight of maggots in Russell Crowe's shoulder wound in Gladiator, but they might be surprised to know that maggot therapy is still being practised worldwide, including in Ireland.

The use of maggots to clean out dead tissue is very effective, says Dr Zena Moore, an expert in wound management and lecturer at the Royal College of Surgeons in Ireland.

Despite having been used here for more than a decade, it hasn’t been employed as much here as in Britain, which may have something to do with the level of awareness and acceptance of the idea.

Welsh company ZooBiotic says it supplies up to 2,000 applications of the greenbottle larvae Lucilia sericata, a type of blowfly, to this island every year, about 600 of which are used in the Republic. It says maggot therapy is used in the treatment of a variety of conditions, such as diabetic foot ulcers, pressure sores, surgical wounds, trauma injuries and burns, and it saves on trips to the operating theatre to clean out problematic wounds.

The greenbottles, farmed in 150 tanks in Bridgend in Wales, lay their eggs on slabs of sugar-coated liver. The collected eggs are disinfected. About 80 per cent are then used in teabag-like pouches, which completely retain the larvae while allowing them to feed.

The unique selling point of maggots is the speed with which they clean out a wound, using a “spit and suck” method of liquifying dead tissue. In doing this the maggots secrete enzymes that help to make the wound area unfavourable to bacterial growth. They will move away from a wound when only healthy tissue is left. Within a few days, the maggots grow from a few millimetres long to more than a centimetre.

A study in the British Medical Journal last year found that larval therapy “significantly” reduced cleaning time for leg ulcer wounds compared with a water-based gel. The authors say their findings “do indicate that larvae are a more effective debriding [cleaning] agent than hydrogel”.

Using larvae didn’t increase the healing rate of the ulcers, and was associated with more pain in the 24 hours before removal of the first treatment. There was no evidence of a difference between larvae and hydrogel in terms of bacterial load over time.

Overall, the study found there was no evidence from the trial on these types of leg ulcer that larval therapy should be used routinely to speed up healing or reduce bacterial load.

However, the authors found that if cleaning a wound is the treatment goal – before skin-grafting or other surgery, for example – then larval therapy should be considered. They add that further research is required to explore the relationship between the cleaning and healing of wounds of different origins.

ZooBiotic plans to hold an education seminar on maggot therapy in Dublin this autumn, according to Gill Davies, director of sales and marketing with the company.