Leeches are ‘worms’ with suckers on each end. Leeches can range in size from from a half of inch to ten inches long. They are brown or black in colour. Some feed on decaying plant material. Others are parasites, feeding on blood and tissue of other animals.
Blood-sucking leeches suck your blood in two ways: they use a proboscis to puncture your skin, or they use their three jaws and millions of little teeth. They live just about anywhere there is water. Leeches find you by detecting skin oils, blood, heat, or even the carbon dioxide you breathe out. Leeches do not feed often. That is because they take in a lot when they do feed.
Doctors often used leeches in the past to draw blood. Some barbers used to do surgery as well as cutting hair, and they used leeches. When a barber finished surgery, he took the bloody bandage and wrapped it around a pole to show he did surgery too. That’s how the white and red swirled barber pole came to be.
Today, maggots and leeches are being used for different reasons. Scientists are studying leech saliva. They believe the substance that stops or prevents blood clots will one day be able to be used on humans. Researchers have also identified several medical compounds which can be developed from leech saliva. The anticoagulant and clot-digesting properties of these substances make them potentially useful as drugs for the treatment of cardiovascular diseases such as heart attacks and strokes. Leeches can be “milked” for their secretions without being harmed, and research is continuing into the possibility of synthetically engineering leech saliva.
Remove the leech
One recommended method of removal is using a fingernail or other flat, blunt object to break the seal of the oral sucker at the anterior end (the smaller, thinner end) of the leech, repeating with the posterior end, then flicking the leech away. As the fingernail is pushed along the person’s skin against the leech, the suction of the sucker’s seal is broken, at which point the leech should detach its jaws.
Common but medically inadvisable techniques to remove a leech are to apply a flame, a lit cigarette, salt, soap, or a 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.
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 have 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, Neem oil and eucalyptus oil. Diluted calcium hydroxide may also be used as a repellent, but may be damaging or irritating to the skin. One other remedy commonly practiced in the western ghats of southern India is castor oil mixed with snuff powder, or powdered tobacco.