Written by Amelia Tait - February 28, 2023

The rise in global antibiotic resistance means huge sums are being invested in ground-breaking treatments. But some scientists are turning back the clock in the hunt for effective alternatives

For several long months in the 1990s, Ronald Sherman traveled all over southern California catching flies.

As a qualified doctor pursuing an infectious diseases fellowship, Sherman was curious about a potential new – and also very old – way to clean wounds.

At medical school, he’d written a paper on the history of maggot therapy, tracing how the creepy crawlies helped heal soldiers in the Napoleonic wars, the American civil war and the First World War.

Now Sherman wanted to test maggots in a modern setting. The problem? No one farmed and sold the species of flies that the doctor needed – so he went out and caught them himself.

Once the specimens were collected and “as soon as everyone stopped laughing”, Sherman got to work. After treating his first patients with maggots, he was impressed by the results, but nonetheless he struggled to get his initial research papers published.

A rejection letter from one journal read: “Publishing the manuscript might be interpreted as an endorsement for a therapy that is ancient.” Yet today, Sherman says, “that same journal probably has two or three articles about maggot therapy every year!”

It is believed that ancient aboriginal tribes used maggots to treat the wounded and some academics argue that the practice “dates back to the beginnings of civilisation”. Hundreds of years later, these superbugs are now used to fight superbugs.

In an age of growing antibiotic resistance, maggots are an alternative to modern medicine, as they help to fight infection by consuming dead tissue and bacteria. Between 2007 and 2019, the number of NHS patients treated with maggots increased by 47 percent.

Meanwhile, there is a farm in Wales that supplies 60,000 medicinal leeches to the NHS and other healthcare providers every year. While most of us imagine that bloodsucking fell out of favour after the Middle Ages, leeches have been consistent healthcare assistants for centuries.

The parasites release chemicals that thin the blood and inhibit clotting, meaning they can prevent tissue death by improving blood circulation in areas where it has slowed. In this way, they can save limbs from amputation after nasty accidents.

Honey, which the ancient Egyptians used to treat wounds thousands of years ago, is in use, too. While medical grade honey dressings are sometimes used by the NHS, in September 2022, scientists at the University of Manchester argued that the sticky stuff should be considered as an alternative to antimicrobial drugs.

“One thing is certain,” said postgraduate researcher Joel Yupanqui Mieles, “rising global antibiotic resistance is stimulating the development of novel therapies as alternatives to combat infections – and honey, we think, has a role to play in that.”

Meet the new medicine – same as the old medicine. In an age where robots can perform hip replacements and livers can be repaired with lab-grown cells, why are ancient practices coming back into favour? Who are the doctors, farmers, professors and patients who have kept our ancestors’ practices alive? And are there more retired remedies hiding in the archives, ready to be revived?

“There is a taboo that gets in the way of people using the technique,” says Sherman of maggot therapy. “But for many practitioners, once they try their first case – even if it’s a last resort – they see what it can do.”

Studies have found that maggots reduce a wound’s surface area and promote healing faster than conventional dressings. Following Sherman’s work and the concurrent work of British doctor Steve Thomas, the NHS accepted the use of maggot therapy in 2004.

In 2005, a private company spun out from the Welsh NHS Trust where Thomas worked – ZooBiotic, now BioMonde – a sterile maggot-production facility in Wales that is currently home to 24,000 flies.

Vicky Phillips, a clinical support manager at BioMonde, educates clinicians about the benefits of maggot therapy. “The larvae will only eat dead tissue,” she explains. BioMonde’s maggots are shipped out in aseptic polyester nets known as BioBags, each one made to order with a patient in mind, the larvae bagged in the morning and shipped in the afternoon in insulated boxes.

“I think there’s only one postcode we haven’t shipped to in the whole of the UK,” she says. BioMonde is the sole provider of medical maggots to the NHS, and an average of 9,000 BioBags are sent out to UK healthcare providers every year.

The bags come in five different sizes and each is used for a four-day treatment cycle, after which the maggots are disposed of as clinical waste. “I always tell patients and clinicians that these are the cleanest little maggots that they’re ever going to meet,” Phillips says – the flies’ eggs are disinfected before they hatch.

While a Nursing Times study published in October 2022 found that a “yuck factor” was preventing nurses from using maggot therapy, Phillips says acceptance has increased over the four years she’s been at BioMonde. “Generally, clinicians are more and more keen to avoid using antibiotic therapy,” she comments.

Patients, somewhat surprisingly, are also keen. Rosalyn Thomas is an acute foot podiatrist for Swansea Bay University Health Board who has been using maggots on her patients for 26 years.

Thomas specialises in diabetic foot care and has found maggot therapy to be “the quickest way to clean up a wound” – it is an alternative to invasive and costly surgery and it is less disruptive for patients, who can often go home after having a bag applied.

For these reasons, Thomas has found that patients are happy to give maggots a go. “Over the 26 years, I’ve only had one patient who took about three weeks to reluctantly agree, but she did agree in the end,” she says. “I can’t recall anybody point blank refusing to have the treatment.”

So what exactly does maggot therapy feel like?

Susan Barnard, a type 1 diabetic who had maggots applied to a foot wound in 2016, says “to begin with, it doesn’t feel like anything, really.” The 48-year-old from Holywood, Northern Ireland, compares BioBags to teabags and says the maggots inside look like grains of rice.

But as the maggots fed on Barnard’s wound, they grew, and then she started to feel “a crawling, like how your skin crawls but without the shivers”. Still, she didn’t feel squeamish about the treatment – she was simply amazed, and “actually felt really guilty” that the maggots had to die after they’d eaten her flesh . . .

[SNIP]