All about Leeches (2)

Medicinal Leech

Reproduction

Leeches are hermaphrodites, meaning each one of them has both female and male reproductive organs (ovaries and testes respectively). Leeches reproduce by reciprocal fertilization, and sperm transfer occurs during copulation. The leech exercising the role of the male will grow a sperm sack near the end of its tail, and the leech playing the female will bite it off, thus reproducing. Similarly to the earthworms, leeches also use a clitellum to hold their eggs and secrete the cocoon.

During reproduction leeches utilize hyperdermic injection of their sperm. They use a spermatophore, which is a structure containing the sperm. Once next to another leech, the two will line up with their anterior side opposite the other's posterior. The leech then shoots the spermatophore into the clitellur region of the opposing leech where its sperm will make its way to the female reproductive parts.

Leeches and a History of Medicine

For over 4000 years, the leech has been a familiar remedy, with Greek and Roman physicians praising the application of this clever invertebrate.

In the 19th century leeches were enjoying a golden age. Millions were raised for medical use as their fame as a cure-all ensued. The mid 1800s saw their constant use for local bloodletting. Druggists administered thousands of leeches to patients with anything from gumboils to facial discoloration.

Leeches were applied to the mouth and inside of the throat using a leech-glass, although patients frequently swallowed them. Patients were relieved only with a salty drink of water or perhaps the most popular cure-all of the day, a couple of glasses of wine. Sometimes the leech would not drink and then had to be encouraged by some blood or cream smeared at the puncture site or bathed in a warm glass of beer until ready.

Once sucking, an average leech would drink blood weighing as much as itself in about 15 minutes and consume between 2.5-5.5 grams of blood (half a teaspoon). If the bite failed to stop bleeding after the leech was removed then vinegar, silver nitrate and hot wires were applied.

Apart from using the English and Scottish leeches, huge numbers were imported from France, Hungary, the Ukraine, Turkey, Romania, Russia, Egypt and Algeria. In 1846 in France alone, 30 million leeches were used. Hospitals in both London and Paris required 13 million between them for that single year. America produced their own leeches and one farm sold over a thousand per day.

Leeches were also caught from the wild by many interesting ways, including men bathing a muddy ditch or in a stream with a glass of pig blood, rolling their trousers up and wading into the water. Here they would wait patiently for leeches to adhere themselves to their legs. After a while, back on land the feeding leeches would be stripped off and sold to leech dealers. The leech industry began its decline due to the over collection of the animal and its discredit by the medical profession. By the end of the 19th century the golden age of the leech had passed.

Today leeches are bred in captivity in many institutions including Bristol Zoo Gardens. Leeches have found new fame in microsurgery, where doctors require the precision of the leech to drain congested blood from wounded sites. Plastic surgeons are particularly grateful for the contribution made by the leech, due to their use in the treatment of difficult grafts and reconstructive surgery.

In the past

In medieval and early modern medicine, the medicinal leech (Hirudo medicinalis and its congeners Hirudo verbana, Hirudo troctina and Hirudo orientalis) was used to remove blood from a patient as part of a process to "balance" the "humors" that, according to Galen, must be kept in balance in order for the human body to function properly. (The four humors of ancient medical philosophy were blood, phlegm, black bile, and yellow bile.) Any sickness that caused the subject's skin to become red (e.g. fever and inflammation), so the theory went, must have arisen from too much blood in the body. Similarly, any person whose behavior was strident and "sanguine" was thought to be suffering from an excess of blood.

The first recorded use of leeches in medicine was in 200 BC by the Greek physician Nicander in Colophon. Hirudotherapy, the use of medicinal leech for medical purposes, was later popularised by Avicenna in The Canon of Medicine (1020s). He considered the application of leech to be more useful than cupping in "letting off the blood from deeper parts of the body." He also introduced the use of leech as treatment for skin disease. Leech therapy became a popular method in medieval Europe, namely the leeches from Portugal and France, due to the influence of his Canon.

A more modern use for medicinal leech was introduced by Abd-el-latif al-Baghdadi in the 12th century, who wrote that leech could be used for cleaning the tissues after surgical operations. He did, however, understand that there is a risk over using leech, and advised patients that leech need to be cleaned before being used and that the dirt or dust "clinging to a leech should be wiped off" before application. He further writes that after the leech has sucked out the blood, salt should be "sprinkled on the affected part of the human body. The use of leeches began to become less widespread towards the end of the 19th century.

Today

Medicinal leeches are now making a comeback in microsurgery. They provide an effective means to reduce blood coagulation, relieve venous pressure from pooling blood (venous insufficiency), and in reconstructive surgery to stimulate circulation in reattachment operations for organs with critical blood flow, such as eye lids, fingers, and ears. The therapeutic effect is not from the blood taken in the meal, but from the continued and steady bleeding from the wound left after the leech has detached. The most common complication from leech treatment is prolonged bleeding, which can easily be treated, although allergic reactions and bacterial infections may also occur.

Because of the minuscule amounts of hirudin present in leeches, it is impractical to harvest the substance for widespread medical use. Hirudin (and related substances) is synthesized using recombinant techniques. Devices called "mechanical leeches" have been developed which dispense heparin and perform the same function as medicinal leeches, but they are not yet commercially available.

Hirudo medicinal

The medicinal leech and the leech therapy are thousands of years old well known medical treatment. The medicinal leech is assigned with problem definitions such as cramp veins, vein diseases and arthritis or tinnitus. One already finds the first recordings over the use of the medicinal leech for the leech therapy in the 2ten century before Christi from the Greek Nikander von Kolophon, who used the leech and the leech therapy particularly for the treatment of poisoned snake bites.

In the modern medicine the medicinal leech and the leech therapy experiences nowadays again renaissance in its use for different diseases.

Apart from the classical areas for the medicinal leech for the leech therapy such as cramp veins, vein diseases, arthritis, tinnitus today the leech therapy is used also in the modern reconstructive and plastic surgery. Here the medicinal leech helps to improve a venous congestion in case of e.g. reimplanting a lost finger through an accident.

The leech therapy

The leech therapy should be accomplished only by experienced Therapists!

How many leeches do I need for a therapy.

The necessary number of leeches depends by the following factors: Age and weight of the patient, the kind of disease and the size of the leeches available.

The leech sucks approx. 30 minutes. One should let the animals in peace suck and under no circumstances when sucking disturb. Likewise should not be under any circumstances smoked in the environment. Sucking should not be artificially interrupted. At the end of sucking the leech of alone drops. Sometimes it happens that the animals suck after that is so slow-acting that they remain hanging on the patient. Into such to fall it helps to drive with a putty under the front suction cup and take so the leech off. Please you make sure however that them the leech thereby not crimping around vomiting the leeches, and thus a possible infection to prevent. For this reason also no salt may be used for removing the leeches.

When chronic illnesses one sets fewer animals for it the therapy however in shorter time intervals is on repeated. With acute diseases one uses more leech and has a longer period up to the next treatment. For a normal adult with standard weight and no further medical treatment and in a healthy condition 10 leeches may be use for a therapy.

All about Leeches (1)

How blood sucking leeches suck our blood?

Two ways:

1. They use a proboscis to puncture our skin.

2. They use their mouths and million of little teeth.

Leeches find us by detecting skin, oils, blood, heat, or even the carbon dioxide we breathe out.

Identification

The bodies of all leeches are divided into the same number of segments, 34, with a powerful clinging sucker at each end. Body shape is variable but to some extent depends on the degree to which their highly muscular bodies are contracted. The mouth is in the anterior sucker and the anus is on the dorsal surface (top) just in front of the rear sucker.

Leeches usually have three jaws and make a Y-shaped incision. The Australian land leech has only two jaws and makes a V-shaped incision. Australian leeches can vary in size from about 7 mm long to as much as 200 mm when extended.

Size range

7 mm long to 200 mm when extended.

Habitat

Most leeches are freshwater animals, but many terrestrial and marine species occur.

Land leeches are common on the ground or in low foliage in wet rain forests. In drier forests they may be found on the ground in seepage moistened places. Most do not enter water and cannot swim, but can survive periods of immersion.

In dry weather, some species burrow in the soil where they can survive for many months even in a total lack of environmental water. In these conditions the body is contracted dry and rigid, the suckers not distinguishable, and the skin completely dry. Within ten minutes of sprinkling with a few drops of water, these leeches emerge, fully active.

Freshwater leeches prefer to live in still or slowly flowing waters, but specimens have been collected from fast flowing streams. Some species are considered amphibious as they have been observed in both terrestrial and aquatic habitats.

Respiration takes place through the body wall, and a slow undulating movement observed in some leeches is said to assist gaseous exchange. Aquatic leeches tend to move to the surface when they find themselves in water of low oxygen content. As a fall in atmospheric pressure results in a small decrease in dissolved oxygen concentrations, rising leeches in a jar of water provided nineteenth century weather forecasters with a simple way of predicting bad weather.

Sensory organs on the head and body surface enable a leech to detect changes in light.

1. The jawed leeches or Gnatbobdellida, have jaws armed with teeth with which they bite the host. The blood is prevented from clotting by production of a non-enzymatic secretion called hirudin. The land leech commonly encountered by bushwalkers is included in this group.

2. The jawless leeches or Rhyncobdellida, insert a needle-like protrusion called a proboscis into the body of the host and secrete an enzyme, hemetin which dissolves clots once they have formed. Leeches which live on body fluids of worms and small freshwater snails possess such an apparatus.

3. The worm leeches or Pharyngobdellida, have no jaws or teeth and swallow the prey whole. Its food consists of small invertebrates.

Feeding and Diet

Most leeches are sanguivorous, that is they feed as blood sucking parasites on preferred hosts. If the preferred food is not available most leeches will feed on other classes of host. Some feed on the blood of humans and other mammals, while others parasitise fish, frogs, turtles or birds. Some leeches will even take a meal from other sanguivorous leeches which may die after the attack.

Sanguivorous leeches can ingest several times their own weight in blood at one meal. After feeding the leech retires to a dark spot to digest its meal. Digestion is slow and this enables the leech to survive during very long fasting periods (up to several months).

Leeches are grouped according to the different ways they feed.

Leeches do not feed often. That is because they take in a lot when they do feed. A few large leeches can drain the life from rabbit in less than half in hour. Leeches feeding unnoticed, until they are the size of small banana.

Removal

One recommended method of removal is using a fingernail to break the seal of the oral sucker at the anterior end (the smaller, thinner end) of the leech, repeating with the posterior end, and then flicking the leech away. As the fingernail is pushed along the person's skin against the leech, the suction of sucker's seal is broken, at which point the leech should detach its jaws.

A common but medically inadvisable technique to remove a leech is to apply a flame, a lit cigarette, salt, soap, or a caustic chemical such as alcohol, vinegar, lemon juice, insect repellent, heat rub, or certain carbonated drinks. These cause the leech to regurgitate its stomach contents into the wound and quickly detach. However, the vomit may carry disease, and thus increase the risk of infection.

Simply pulling a leech off by grasping it can also cause regurgitation, and adds risks of further tearing the wound, and leaving parts of the leech's jaw in the wound, which can also increase the risk of infection.

An externally attached leech will detach and fall off on its own when it is satiated on blood, usually in about 20 minutes (but will stay there for as long as it can). Internal attachments, such as nasal passage or vaginal attachments are more likely to require medical intervention.

Treatment

After removal or detachment, the wound should be cleaned with soap and water, and bandaged. Bleeding may continue for some time, due to the leech's anti-clotting enzyme. Applying pressure can reduce bleeding, although blood loss from a single bite is not dangerous. The wound normally itches as it heals, but should not be scratched as this may complicate healing and introduce other infections. An antihistamine can reduce itching, and applying a cold pack can reduce pain or swelling.

Some people suffer severe allergic or anaphylactic reactions from leech bites, and require urgent medical care. Symptoms include red blotches or an itchy rash over the body, swelling away from the bitten area (especially around the lips or eyes), feeling faint or dizzy, and difficulty breathing.

Prevention

There is no guaranteed method of preventing leech bites in leech-infested areas. The most reliable method is to cover exposed skin. The effect of insect repellents is disputed, but it is generally accepted that strong (maximum strength or tropical) insect repellents do help prevent bites.

Leech socks can be helpful in preventing bites when the full body will not be at risk of contact with leeches. Leech socks are pulled over the wearer’s trousers to prevent leeches reaching the exposed skin of the legs and attaching there or climbing towards the torso. The socks are generally a light color that also makes it easier to spot leeches climbing up from the feet and looking for skin to attach to.

There are many home remedies to help prevent leech bites. Many people have a great deal of faith in these methods, but none of them has been proven effective. Some home remedies include: a dried residue of bath soap, tobacco leaves between the toes, pastes of salt or baking soda, citrus juice, and eucalyptus oil. Diluted calcium hydroxide may also be used as a repellent, but may be damaging or irritating to the skin.

Bloodletting (or blood-letting) is the withdrawal of often considerable quantities of blood from a patient to cure or prevent illness and disease. It was the most common medical practice performed by doctors from antiquity up to the late 19th century, a time span of almost 2,000 years.The practice has been abandoned for all except a few very specific conditions.

It is conceivable that historically, in the absence of other treatments for hypertension, bloodletting could sometimes have had a beneficial effect in temporarily reducing blood pressure by a reduction in blood volume.However, since hypertension is very often asymptomatic and thus undiagnosable without modern methods, this effect was unintentional. In the overwhelming majority of cases, the historical use of bloodletting was harmful to patients.

Medicinal leech

Leeches and a History of Medicine

For over 4000 years, the leech has been a familiar remedy, with Greek and Roman physicians praising the application of this clever invertebrate.

In the 19th century leeches were enjoying a golden age. Millions were raised for medical use as their fame as a cure-all ensued. The mid 1800s saw their constant use for local bloodletting. Druggists administered thousands of leeches to patients with anything from gumboils to facial discoloration. Leeches were applied to the mouth and inside of the throat using a leech-glass, although patients frequently swallowed them. Patients were relieved only with a salty drink of water or perhaps the most popular cure-all of the day, a couple of glasses of wine. Sometimes the leech would not drink and then had to be encouraged by some blood or cream smeared at the puncture site or bathed in a warm glass of beer until ready.

Once sucking, an average leech would drink blood weighing as much as itself in about 15 minutes and consume between 2.5-5.5 grams of blood (half a teaspoon). If the bite failed to stop bleeding after the leech was removed then vinegar, silver nitrate and hot wires were applied.

Apart from using the English and Scottish leeches, huge numbers were imported from France, Hungary, the Ukraine, Turkey, Romania, Russia, Egypt and Algeria. In 1846 in France alone, 30 million leeches were used. Hospitals in both London and Paris required 13 million between them for that single year. America produced their own leeches and one farm sold over a thousand per day.

Leeches were also caught from the wild by many interesting ways, including men bathing a muddy ditch or in a stream with a glass of pig blood, rolling their trousers up and wading into the water. Here they would wait patiently for leeches to adhere themselves to their legs. After a while, back on land the feeding leeches would be stripped off and sold to leech dealers. The leech industry began its decline due to the over collection of the animal and its discredit by the medical profession. By the end of the 19th century the golden age of the leech had passed.

Today leeches are bred in captivity in many institutions including Bristol Zoo Gardens. Leeches have found new fame in microsurgery, where doctors require the precision of the leech to drain congested blood from wounded sites. Plastic surgeons are particularly grateful for the contribution made by the leech, due to their use in the treatment of difficult grafts and reconstructive surgery.

In the past

In medieval and early modern medicine, the medicinal leech (Hirudo medicinalis and its congeners, Hirudo verbana, Hirudo troctina and Hirudo orientalis) was used to remove blood from a patient as part of a process to "balance" the "humors" that, according to Galen, must be kept in balance in order for the human body to function properly. (The four humors of ancient medical philosophy were blood, phlegm, black bile, and yellow bile.) Any sickness that caused the subject's skin to become red (e.g. fever and inflammation), so the theory went, must have arisen from too much blood in the body. Similarly, any person whose behavior was strident and "sanguine" was thought to be suffering from an excess of blood.

The first recorded use of leeches in medicine was in 200 BC by the Greek physician Nicander in Colophon. Hirudotherapy, the use of medicinal leech for medical purposes, was later popularized by Avicenna in The Canon of Medicine (1020s). He considered the application of leech to be more useful than cupping in "letting off the blood from deeper parts of the body." He also introduced the use of leech as treatment for skin disease. Leech therapy became a popular method in medieval Europe, namely the leeches from Portugal and France, due to the influence of his Canon. A more modern use for medicinal leech was introduced by Abd-el-latif al-Baghdadi in the 12th century, who wrote that leech could be used for cleaning the tissues after surgical operations.

He did, however, understand that there is a risk over using leech, and advised patients that leech need to be cleaned before being used and that the dirt or dust "clinging to a leech should be wiped off" before application. He further writes that after the leech has sucked out the blood, salt should be "sprinkled on the affected part of the human body. The use of leeches began to become less widespread towards the end of the 19th century.

Today

Medicinal leeches are now making a comeback in microsurgery. They provide an effective means to reduce blood coagulation, relieve venous pressure from pooling blood (venous insufficiency), and in reconstructive surgery to stimulate circulation in reattachment operations for organs with critical blood flow, such as eye lids, fingers, and ears. The therapeutic effect is not from the blood taken in the meal, but from the continued and steady bleeding from the wound left after the leech has detached.The most common complication from leech treatment is prolonged bleeding, which can easily be treated, although allergic reactions and bacterial infections may also occur.

Because of the minuscule amounts of hirudin present in leeches, it is impractical to harvest the substance for widespread medical use. Hirudin (and related substances) is synthesized using recombinant techniques. Devices called "mechanical leeches" have been developed which dispense heparin and perform the same function as medicinal leeches, but they are not yet commercially available.

Hirudo medicinalis

The medicinal leech and the leech therapy are thousands of years old well known medical treatment. The medicinal leech is assigned with problem definitions such as cramp veins, vein diseases and arthritis or tinnitus. One already finds the first recordings over the use of the medicinal leech for the leech therapy in the 2ten century before Christi from the Greek Nikander von Kolophon, who used the leech and the leech therapy particularly for the treatment of poisoned snake bites.

In the modern medicine the medicinal leech and the leech therapy experiences nowadays again renaissance in its use for different diseases.

Apart from the classical areas for the medicinal leech for the leech therapy such as cramp veins, vein diseases, arthritis, tinnitus today the leech therapy is used also in the modern reconstructive and plastic surgery. Here the medicinal leech helps to improve a venous congestion in case of e.g. reimplanting a lost finger through an accident.

The leech therapy

The leech therapy should be accomplished only by experienced Therapists!

How many leeches do I need for a therapy?

The necessary number of leeches depends by the following factors: Age and weight of the patient, the kind of disease and the size of the leeches available.

The leech sucks approx. 30 minutes. One should let the animals in peace suck and under no circumstances when sucking disturb. Likewise should not be under any circumstances smoked in the environment. Sucking should not be artificially interrupted. At the end of sucking the leech of alone drops. Sometimes it happens that the animals suck after that is so slow-acting that they remain hanging on the patient.

Into such to fall it helps to drive with a putty under the front suction cup and take so the leech off. Please you make sure however that them the leech thereby not crimping around vomiting the leeches, and thus a possible infection to prevent. For this reason also no salt may be used for removing the leeches.

When chronic illnesses one sets fewer animals for it the therapy however in shorter time intervals is on repeated. With acute diseases one uses more leech and has a longer period up to the next treatment. For a normal adult with standard weight and no further medical treatment and in a healthy condition 10 leeches may be use for a therapy.

Leeches

Leeches Fact

Leeches are annelids comprising the subclass Hirudinea. There are freshwater, terrestrial, and marine leeches. Like the Oligochaeta, they share the presence of a clitellum. Like earthworms, leeches are hermaphrodites. Some, but not all leeches are hematophagous.

There are 650 known species of leeches. The largest leech discovered measured 18 inches. About one fifth of leech species live in the sea, where they feed on fish. The leech has 32 brains - 31 more than a human. The Hirudo leech lays its babies within a cocoon; whereas the Amazon leech carries its babies on its stomach - sometimes as many as 300. Not all leeches are bloodsuckers. Many are predators which eat earthworms, etc. The Amazon leech uses a different method of sucking blood. It inserts a long proboscis into the victim, as opposed to biting.

The bite of a leech is painless, due to its own anesthetic. The Hirudo leech injects an anti-coagulant serum into the victim to prevent the blood clotting. The leech will gorge itself until it has had its fill and then just fall off. The leech will gorge itself up to five times its body weight.