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| Treatment of wounds with live larvae that antibiotics do not work on |
From a laboratory in Campinas in Sao Paulo, Brazil, the tiny larvae have been sent to hospitals in several Brazilian cities.
These were the larvae of two species of bees that were developed for a very specific medical purpose and that medical purpose is the 'treatment of hard-to-heal wounds.'
Campinas State University biologist Patricia Thiessen not only created the larvae but also fed and sterilized them.
In fact, these larvae feed on the dead tissues of the human body.
So when the larvae are placed on the skin of infected wounds—for example, in wounds caused by diabetes or venous ulcers—the larvae eat the dead tissue and secrete healing substances, making the use of antibiotics ineffective. Reduce or eliminate the need for them altogether.
The technique, known as larva therapy, is still in its infancy in Brazil, with its roots in ancient medicine.
Although this practice is somewhat counterintuitive, there are historical records showing that thousands of years ago, Mayan people in Central America and Australians used larvae to heal wounds.
For example, the Maya washed tissues with animal blood, then exposed them to sunlight to attract flies, and then applied the larvae to human wounds where they began to spread.
The technique was also experimentally documented by physicians in medieval Europe, the American Civil War (1861–65), and World War I (1914–18).
By the 20th century, the inventions of penicillin and antibiotic drugs eliminated such treatments.
The problem is that more and more antibiotics today lose their effectiveness against resistant bacteria, which the World Health Organization (WHO) considers one of the ten greatest threats to public health today.
As a result, in recent decades more and more health professionals have turned to the larvae to treat chronic and infected wounds that do not heal with antibiotics and traditional dressings.
Researchers in Brazil want the National Health Surveillance Agency (Anvisa) to allow this type of therapy. Because this type of treatment is not currently classified as a drug or medical treatment.
But it's a treatment that faces many obstacles and risks.
The larvae eat the infected tissue
Maggot therapy (therapy using insects or mites) was first used by American physician William Beer in 1917 to treat soldiers in France during World War I.
In a hospital on the front lines, Beer saw two patients who were in great pain: soldiers with open wounds on their legs and stomachs, who had spent days without treatment in trenches where they could not even get water or food. And they were fighting in a dirty environment.
However, Beer noted that both soldiers' wounds were filled with maggots. And that, despite appearing weak, the two soldiers arrived at the hospital without fever or odor, or signs of serious infection.
Beer wrote in his study that 'when I looked at the wounds, especially the thigh wounds, I was astonished at the good condition of the patients.'
After this incident, the American doctor decided to test the effect of the larvae on wounds in the laboratory, identifying the healing potential of some of them, although it is important to mention here that the larvae used by Beer were not sterilized. were performed, they led to serious secondary infections such as tetanus in some patients.
Sterilization
More than a century later, today's maggot therapy is very different, and unlike Beer or Mayan, it is practiced today with hygiene in mind. However, its basis is the same: namely, bees.
Actually, very special bees and the UK only uses one of the millions of species of bees for medicinal purposes called Lucilia Select.
Speaking to BBC Brazil, Dr. Yamni Nigam, professor of biomedical sciences at Swansea University in the UK, says it is a species of fly known to breed in rubbish and decaying corpses. And this is what enables its larvae to treat chronic human wounds.
"They feed on infected and decayed tissues, clean the wound, and create a healthy skin growth process," says Nigam.
Its main use is in diabetic patients whose wounds, if left untreated, are at risk of amputation or death.
Nigam explains that these are wounds that do not heal and sometimes the patient does not even realize it, because the nerves in the injured area stop working. Their nervous system deteriorates and usually, in such patients, larvae are used.
He says the larvae of the Lucilia select bee are a non-invasive species, unable to invade the human body, and do not eat healthy tissue, so they are perfect for the job.
In the UK, this treatment is carried out in the laboratory with sterile larvae and collected in small biological bags similar to tea bags.
These bags are kept on the infected wound for five days under medical supervision and then discarded.
Seven wounds to the pore-sac larvae allow direct contact and feeding on diseased waste can cause larvae to quadruple their size from 3 to 12 mm.
Nigam explains that the larvae don't have teeth: they just secrete a liquid that passes through the pouch to digest and clean the wound. And then they swallow the liquid again and during this whole process, they (larvae) remain inside the sac continuously. She explains that this treatment not only helps prevent disability but also reduces the need for antibiotics.
Maggot therapy has been used in a few British Public Health Service (NHS) hospitals since the 2000s, around the same time it was approved by the US Drug Regulatory Agency (FDA).
British larvae are cultured, sterilized, and packaged by the Welsh company Bio Monde. The company told BBC News Brazil that it supplies more than 5,000 biobags to the NHS annually.
The company also has a unit in Germany which exports larvae to European countries.
According to the NHS, in some cases, the treatment causes pain, skin irritation, or bleeding, and in these cases, the larvae must be removed.
"The larvae produce anticoagulants, so we can't use them in patients who are at high risk of bleeding," says Dr. Nigam.
Patricia Thiessen of Brazil cautioned that it is important to point out that this type of treatment should never be done without medical experts and that the larvae should be sterilized in the laboratory.
She further explains that 'you should never use wild larvae, because (someone who is not an expert) has no way of knowing if it is a harmless and safe species of larva and Nor do they know how much bacteria these larvae can digest.
But if the risks of therapy are less than the potential benefits (eg, disability (limb amputation) and prevention of mass infection), etc. why is the treatment so restricted?
Disgust
Yamni Nigam says that this method of treatment is still being used. We have used it only on very difficult wounds that are otherwise untreatable. And we are working to use it on other wounds as well.
"Why do we leave larval treatment only as a last resort?" she asks. Why do we wait for some patients to suffer for years, sometimes trying different types of bandages and ointments, when using the larvae for only four days would be enough?'
Last year Nigam and his colleagues conducted a poll in the UK, in which only 36 percent of 412 respondents said they would agree with using maggots to treat a hypothetical painful wound.
According to the survey, the main concern with this therapy is obesity.
Other difficulties, according to Nigam, are that, unlike traditional medicines and ointments, the larvae are not so easily produced and stored, and they often face resistance from doctors and nurses.
But he says superbugs have spurred new research.
"Bacteria are highly intelligent creatures," says Nigam. Some antibiotics work against certain diseases, but in most cases, bacteria settle in the wounds and form a wall, which we call a bacterial biofilm, which is something that is very resistant to antibiotics and this is very difficult to treat.'
"We were able to show in the laboratory and in patients that the larvae were not only able to break down this biofilm but that their fluid also prevented it from forming."
Experts say that as this knowledge advances, it is possible that in the future the fluid produced by the larvae could be used to protect human prostheses from water before surgery, for example from infection. To prevent
Nigam believes that we need to change the way we look at these creatures.
"I think larval therapy is not going to be very popular because of the smell factor and people will always be reluctant."
She says, "I think that the negative perception associated with insects, bees, and insects needs to be changed." We need to think of them as medicine or medical devices, not something hard to see in the trash.'