The leeches used in leech therapy are not chosen at random. Only medical leeches specially bred for this purpose in isolated laboratory conditions are suitable for treatment. These leeches have had no contact with the external environment, ensuring they are free from diseases and bacteria, making the therapy with their participation safe for health.
Breeding of medical leeches
In the past, leeches obtained from the natural environment, which fed on the blood of random hosts and were often infected with bacterial or viral diseases, were used for leech therapy. Applying such leeches to a patient’s skin transferred pathogens to their body, leading to severe conditions such as myocarditis or meningitis.
Currently, the leeches used for treatments come from laboratory breeding, where they are raised in isolated conditions. They are fed in a controlled manner with blood from animals that veterinarians have vetted. The EURO-BION laboratories are gradually introducing a new feeding method with the blood substitute preparation HirudoCibum.
Unfortunately, medical leeches from illegal fishing in the natural environment or breeding in various open water bodies, where their feeding cannot be controlled, are still available for sale. These leeches feed on the blood of insects, birds, and rodents, often diseased or carriers of swine or bird flu, posing a potential risk of infections with viral, bacterial, parasitic, and zoonotic diseases.
Therefore, leeches must have a certificate of origin to be used in leech therapy. Verifying this helps to avoid cases of illness after treatment, as seen in the past.
What does a medical leech look like?
The Hirudo verbena leech used for therapy reaches about 1.2 cm in length and 1 cm in diameter, although its body can contract and elongate. When intensely fed, leeches can reach a height of even 0.4 m in breeding. The body of a medical sponge is perfectly smooth and slightly flattened – the dorsal side is convex, and the ventral side is flat. It is divided along its entire length by circular grooves into regular rings (one segment of internal segmentation corresponds to five rings of external segmentation). Usually, the dorsal side of the leech has shades of green and six lines of orange colour, while the ventral side is uniformly teal-olive coloured, bordered on both sides by a dark stripe.
The leech’s mouth opening, leading to the oral cavity, is located on the suction cup at the front of its body. Inside the mouth opening are radially arranged three pairs of jaws. Each has from 60 to 100 microscopic sharp teeth, with which the leech can bite through the skin to a depth of about 1.5 mm. Each tooth has an opening of the secretory canal, through which protein and mucous hirudin compounds produced in the salivary glands flow into the patient’s body during feeding.
Leech therapy procedure
It’s not enough to verify the origin of medical leeches; it’s also necessary to ensure that the person performing the leech therapy procedure has the competence and knowledge required to conduct it according to all safety rules. The place where treatment with leeches is performed should allow for maintaining high hygienic standards and monitoring the patient’s condition during therapy.
It’s also important to be aware that a leech applied to one patient cannot be reused for therapy involving another patient. Such a leech could transfer dangerous viruses such as hepatitis or HIV.
How are medical leeches applied?
The leech therapy procedure itself is not painful. However, at the moment the leech attaches to the skin, a slight discomfort is felt – patients compare this sensation to a mosquito bite. The leech saliva contains anaesthetic substances that additionally neutralise any sensation of pain.
For the procedure, 2 to 10 leeches are used at a time (depending on the needs), and each of them sucks 10-15 ml of blood. Notably, a leech is attached to a specific place and is not moved around the body afterwards. Once connected, it remains for about 1.5 hours, usually until it falls off.
After the leech therapy is completed, the wounds are cleaned with a disinfectant and covered with a sterile dressing. A mark on the skin and slight swelling may persist for a few days.
Medical leeches are considered living pharmacological laboratories. To date, more than 100 bioactive organic compounds have been isolated from them. Therapy with their participation can bring many health benefits. Check it out and see for yourself.