Maggot therapy has been around since ancient times and is still used in our hospitals today to treat particularly troublesome wounds. But where do the maggots come from?

Deep in the base­ment of West­mead Hos­pi­tal is a door with a warn­ing sign which reads: Insec­tary- ensure air cur­tain is ON while room is in use.

Inside are a series of mesh cages filled with flies and they are care­ful­ly looked after by a small team of ded­i­cat­ed scientists.

It’s where NSW Health Pathology’s Med­ical Ento­mol­o­gy team har­vests the mag­gots that are used by hos­pi­tals across Aus­tralia, and even sent to health ser­vices over­seas, to treat patients whose wounds are not respond­ing to more con­ven­tion­al med­ical treatments.

They are the sole sup­pli­ers of mag­gots for med­ical pur­pos­es in Australia.

How does maggot therapy work?

Mag­got debride­ment ther­a­py (MDT) involves plac­ing ster­ile fly lar­vae (live mag­gots) on open wounds to assist in the removal of dead and infect­ed tissue.

The mag­gots are the imma­ture stage of the fly species Lucil­ia ser­i­ca­ta, a com­mon blowfly. It is the main species of fly utilised world­wide for MDT, as the fly’s young have the unique feed­ing behav­iour of devour­ing devi­talised tis­sue, whilst leav­ing the sur­round­ing healthy tis­sue intact. (1)

MDT was once a rou­tine pro­ce­dure in hos­pi­tals through­out Europe, the US and Cana­da dur­ing the 1930s and ear­ly 1940s. The med­ical jour­nals from this era list osteomyelitis, abscess­es, car­bun­cles, burns, cel­luli­tis, gan­grene, and leg ulcers as hav­ing been suc­cess­ful­ly treat­ed. But with the advent of antibi­otics and the devel­op­ment of new sur­gi­cal tech­niques MDT slipped into obscurity.

How­ev­er, inter­est was revived when med­ical tri­als in the 1980s con­clud­ed the ther­a­py still had many ben­e­fits to offer patients in the treat­ment of chron­ic wounds. Not only do the mag­gots remove necrot­ic tis­sue in a pre­cise man­ner, but they also assist in con­trol­ling infec­tion and pro­mote the regen­er­a­tion of healthy tis­sue and healing.

How do we harvest maggots?

The insec­tary at the Insti­tute of Clin­i­cal Pathol­o­gy and Med­ical Research at West­mead Hospital’s was estab­lished by Mer­i­lyn Geary around the year 2000 to pro­vide a dis­in­fect­ed source of mag­gots for med­ical purposes.

NSW Health Pathology’s Direc­tor of Med­ical Ento­mol­o­gy Stephen Doggett (pic­tured top) says ensur­ing the mag­gots are clean is a vital first step in the process.

“Once the flies lay their eggs, we wash the eggs with an anti­sep­tic solu­tion to remove any bac­te­ria,” he said.

“The eggs are then col­lect­ed and put into a ster­ile media to grow – we use egg yolk and that’s what they grow in.

“After they hatch there are three lar­val stages, and we breed them until they hit the sec­ond stage. They are then col­lect­ed and packed into vials, after checks that they are free of bac­te­ria, to send off to where they are need­ed,” Stephen explained.

Each vial con­tains about 100 mag­gots, and they are placed direct­ly onto the patient’s wound.

The wound is then ban­daged with spe­cial mate­r­i­al to keep the mag­gots in place, while also allow­ing air­flow to the wound. The mag­gots are left on the wound for two days and after they do their work, they are removed by nurs­ing staff and dis­posed of.

Is it making a comeback?

Stephen says depend­ing on the size, depth and com­plex­i­ty of the wound, a patient may need more than one appli­ca­tion of maggots.

“In most cas­es sim­ple wounds would only need one appli­ca­tion, but we did have a case a few years back when a patient required 45 appli­ca­tions before his wound was under control.

“The treat­ment was ulti­mate­ly suc­cess­ful and avoid­ed what would oth­er­wise have almost cer­tain­ly been the ampu­ta­tion of his foot.”

He thinks it’s a treat­ment that has found its time again.

“It is tak­ing time to find accep­tance in the med­ical com­mu­ni­ty, but once a patient receives the treat­ment, they say they would have it again.

“We have a sit­u­a­tion where antibi­ot­ic resis­tance is grow­ing. Mag­got ther­a­py is cheap, and it works.”

1. Mer­i­lyn J Geary, The Broad Street Pump, April 2010

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