Hirudo Medicinalis: A Medicinal Leech
Hirudo medicinales is a medicinal leech. It is an invertebrate species, more precisely a type of annelid, which belongs to the Hirudinidae family. This type of leech has been used widely in medicine throughout history.
Medical leech and its history
The therapeutic use of medicinal leeches is already mentioned in the ancient civilizations of Egypt, Greece, Rome and Mesopotamia . Even during the Middle Ages, leeches were used in various treatments.
This was due to the belief that the body was made up of four bodily fluids: blood, phlegm, yellow bile, and black bile. It was believed that changing the balance between the bodily fluids led to various diseases.
The removal of the most important body fluid, contaminated blood, was seen as essential to restore balance. Therefore, bleeding was carried out or therapy based on medicinal leeches was carried out.
Medical leech and its anatomy
The medicinal leech is a hermaphroditic, segmented worm that belongs to the group of annelids and the Hirudinidae family. The species Hirudo Medicinales, which comes from a family of more than 600 species, is the one that is particularly valued in the field of medicine.
If the animals are well fed, they can grow up to twelve centimeters in length. If they haven’t eaten, they are only a third of it. Characteristic for the species are two suction cups with which they can suck.
They have these two suction cups in different places: one is their mouth, small and movable with three jaws. They suck blood with him. Each jaw has between 60 and 100 teeth, which give the animal a set of teeth in the shape of a “Y”.
The other suction cup is called the anal suction cup. The animal uses it to first suck in and move.
Components of the saliva of the medicinal leech
The salivary glands of the medicinal leech release a number of components that have various therapeutic properties. We can briefly list the following:
- Anticoagulant. The most popular substance is called hirudin, it inhibits the blood-clotting effect of thrombin.
- Vasodilator. Various substances that are similar to histamine make blood flow easier by widening the arteries.
- Anesthetic. The bite is painless due to the anesthetic agents that a medicinal leech expels.
- Anti-inflammatory
- Antimicrobial
- Proteolytic enzymes
How is a medicinal leech used?
The therapy with medicinal leeches is called leech treatment. The animals are kept in glass containers, which are closed with a damp compress and kept in a cool place. You can’t hermetically seal it.
Tweezers and a glass are used to move the leeches. So they can’t move around and suck in the optimal place. The skin has to be clean and if the animal doesn’t bite it is rubbed with sugar water.
The animals let go when they have suckled themselves full of blood. The skin then releases abundant tissue fluid from the wound for hours. Therefore, a wound bandage is used, which is changed the next day to observe the healing progress.
After a few days, the skin area shows a noticeable improvement. If a leech does not let go, although it has soaked up, salt water is used. This makes it easier to let go and avoids infections that can occur if you pull it away.
Leeches can only be used once. After use, they must be isolated and killed. There are no known cases of infection resulting from the bite.
Diseases that have been treated with leeches
The diseases for which this type of therapy has been used include the following:
- Inflammation of the joints
- Plastic reconstruction surgery
- migraine
- External hemorrhoids
- Chronic skin eczema
An anecdote has it that centuries ago pilgrims on the Way of St. James often stopped near ponds and rivers. There they refreshed themselves and rested from the exertions of the walk. In doing so, they had some unexpected allies. The leeches relieved her edema and prevented thromboembolism from occurring.
The benefits and contraindications of medical leeches
The leech treatment has no side effects and no negative consequences. It is safe and completely painless. On the other hand, it must be mentioned that there are a number of contraindications.
Their use is not allowed in patients with a weakened immune system or arterial insufficiency. One must also find out in advance about the possible risk of Aeromonas hydrophila infection .
This bacterium has a symbiotic relationship with the medicinal leech. It lives in its bowels and releases enzymes that make blood digestion easier.
The leech treatment is only used in those cases where absolutely no other solution has been found. Of course, you always have to inform the patient beforehand and obtain their consent. It is also necessary to mention that this treatment can only take place in a hospital.
