Lucilia sericata larvae
Effect measure has got a good post on this.
The Guardian has now got a layman’s summary of the paper. It’s published in association with the BMJ but nonetheless seems a fairly balanced summary.
***Edit 21/03/2009 13:40***
Changes: 1. Image caption changed to describe species. 2. Quoted both BBC and Times more extensively, with headlines, for fairer comparion. 3. Added paragraph below:
Let me just clarify that I think that while nothing in either report is untrue, the fact that the two headlines seem to be suggesting very different things about the study suggests that one of them is more balanced. The Times story focuses on debridement, rather than time to healing or pain. In the words of the study authors:
the study raises uncertainty about the role of debridement in the care of leg ulcers. Although debridement is viewed as an important part of preparationof the wound bed, data describing the relation between debridement and healing are sparse. Research is required to explore the relation between debridement, healing, and microbiology as well to better understand the value of debridement as an outcome from the patient’s perspective.
A randomised controlled trial on maggot therapy was published in this week’s British Medical Journal. The researchers’ conclusion:
Larval therapy did not improve the rate of healing of sloughy or necrotic leg ulcers or reduce bacterial load compared with hydrogel but did significantly reduce the time to debridement and increase ulcer pain.
Seen in the BBC as this:
Maggot therapy hope ‘premature’
Maggots may not have the miracle healing properties that have been claimed, a UK study suggests. Researchers comparing maggots with a standard “hydrogel” in treating leg ulcers found little difference…
…There was no significant difference in the time it took the ulcer to heal between the two treatments or in quality of life.
Maggots were not more effective than hydrogel treatment at reducing the amount of bacteria present or in getting rid of MRSA and were, on average, associated with more pain.
Compare with this:
When it comes to wound healing, the maggot cleans up
A study by a team of British scientists, published today, lends support to the use of the maggot in high-tech healthcare. They found that, left to graze on the skin, maggots can clean wounds that fail to heal five times faster than conventional treatments…
…Professor Nicky Cullum, a specialist in wound care, who led the maggot therapy study published in today’s British Medical Journal, said that maggots had cleaned wounds in 14 days — compared with 72 days with gel treatment. She said there was anecdotal evidence of increasing maggot use in the NHS.
The Times of London
It is a classic mistake in science reporting to fail to distinguish the subtleties in phrasing of positive vs. negative outcomes. While debridement was indeed faster the primary outcome – the wound’s actual healing – was no faster. And to top it off, the levels of pain reported were increased. This is certainly no miracle cure. If you read Nicky Cullum’s letter to the BMJ from 2006 entitled Not so fast with vacuums and maggots as firstline treatment you might also infer that the Times selectively quoted Prof. Cullum, who does not appear to be a maggot therapy enthusiast, to make it sound like she was supporting maggot use as first-line treatment.
I suspect that this story was intentionally misreported, in order to appeal to those readers who like the sound of maggots because they are ‘natural’. It is worth bearing in mind that maggots also ‘naturally’ cause disease by feeding on necrotic tissue – this is called fly strike or myiasis (warning: nasty pictures).
I have e-mailed this to Ben Goldacre at Bad Science.