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doi:10.1111/jpc.12701
EDITORIAL
The much maligned leech
Most people find leeches repulsive. Leeches are segmented annelid worms from the subclass Hirudinea. Most leeches are haematophagous, literally blood-eaters. They suck blood by injecting into the host’s bloodstream an anticoagulant hirudin. They are mainly hermaphrodites and belong to the class Clitellata, as they have a clitellum near their gonads, not far from their heads. About 500 of the 700 known species live in fresh water. Leech infestation is common where children are constantly exposed to wetland environments. While local skin attachment is by far the commonest site, leeches sometimes penetrate body orifices and have been described causing disease in places that defy belief, including the eye, nose, larynx, urethra, bladder, vagina and rectum.1 The medicinal leech Hirudo medicinalis has a long and distinguished history.2 Leeches can be seen in ancient Egyptian cave paintings over 3500 years old, at the beginning of what we call human civilisation. Their medicinal use was first documented in a medical poem ‘Alexipharma’ by Nicades of Colophain, who was born in 200 BC. Around the first century AD, descriptions of medicinal leeching appeared in the Arabic, Chinese, Persian and Sanskrit literature. It was the Romans who gave leeches the name Hirudo. The word leech derives from the Anglo-Saxon word laece, a physician, indicating the close tie between leeches and doctors.2 Leeches were farmed and were so popular in the United States and Europe in the early 19th century that there was a shortage.2 But what was the scientific basis of this therapy? The concept of blood-letting as therapeutic may derive from the belief of Asclepius and his Syrian pupil Themisson of Laodicae that evil spirits causing illness could be removed by blood loss. Galen described four bodily humours, blood, phlegm, yellow bile and black bile, which needed to be in equilibrium for good health. If this equilibrium was disturbed, he argued, health could be
restored by blood-letting. Barber-surgeons in the Middle Ages had patients grip a staff tightly, causing their veins to become prominent and easily bled. The bleeding was often done using leeches and blood dripped onto linen bandages. It has been suggested that the image of blood-stained bandages wrapped around the barber’s white pole gave rise to the red and white pole still displayed outside some hairdressing salons.3 The leech was a kinder option than alternative means of blood-letting such as lancets. Why are we so repelled by leeches? Although leeches can carry blood-borne viruses, they have not been shown to transmit them. In contrast, blood-sucking vampire bats are important vectors of rabies. It is interesting to speculate that mythological human vampires could owe their conception to blood-sucking leeches and bats. Many different cultures have ancient myths of blood-sucking creatures, often in human form. In Europe, vampire stories only became really popular in the 18th century, when the name vampire was first used. Despite the widely known legend of Count Dracula, many vampires were women. Doctors increasingly realised that the most effective use of leeches was to decompress inaccessible collections causing problems such as enlarged haemorrhoids or a prolapsed rectum. This more modern use of leeches has seen a modest resurgence over the last 25 years. Microsurgeons have used leeches to salvage skin and flaps compromised by venous congestion.4 As an infectious disease physician, I was intrigued to read that leech therapy is not infrequently complicated by infection with the Gram-negative rod Aeromonas, which can be prevented by prophylactic ciprofloxacin, given either to the patient or put in the leeches’ water. Less commonly but more dramatically, leeches have been used to treat traumatic macroglossia and to improve microcirculation to the hands of children with meningococcal or pneumococcal purpura fulminans. The leech can cause disease in children has been used as therapy of highly dubious efficacy for millennia, but is now being used therapeutically with a slightly stronger rationale. So far, there have been no randomised controlled trials of leeches although, to my delight, a search of the Cochrane library revealed a protocol for a trial of leech therapy for osteoarthritis.5 It will be an inventive mind that comes up with a sham leech for a double-blind trial.
References 1 Hannan MJ, Hoque MM. Leech infestation in children through body orifices: experience in a hospital in Bangladesh. World J. Surg. 2012; 36: 2090–2. 2 Whitaker IS, Rao J, Izadi D, Butler PE. Historical article: Hirudo medicinalis: ancient origins of, and trends in the use of medicinal leeches throughout history. Br. J. Oral Maxillofac. Surg. 2004; 42: 133–7.
Journal of Paediatrics and Child Health 50 (2014) 661–662 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
661
The much maligned leech
D Isaacs
3 Fitzharris L A History of the Barber’s Pole. Wonders & Marvels, 2011. Available from: http://www.wondersandmarvels.com/2011/10/a-history -of-the-barbers-pole.html [accessed March 2014]. 4 Whitaker IS, Josty IC, Hawkins S et al. Medicinal leeches and the microsurgeon: a four-year study, clinical series and risk benefit review. Microsurgery 2011; 31: 281–7. 5 Croft AM, Chandra S, Perez Fernandez GA, Michalsen A. Leeches (Hirudinea) for osteoarthritis (Protocol). Cochrane Database Syst. Rev. 2014; 2: CD010962. doi: 10.1002/14651858.CD010962.
Professor David Isaacs Editor-in-Chief Children’s Hospital at Westmead Sydney, New South Wales Australia
Sunflower, by Sali Tipa from Operation Art 2012.
662
Journal of Paediatrics and Child Health 50 (2014) 661–662 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
doi:10.1111/jpc.12701
EDITORIAL
The much maligned leech
Most people find leeches repulsive. Leeches are segmented annelid worms from the subclass Hirudinea. Most leeches are haematophagous, literally blood-eaters. They suck blood by injecting into the host’s bloodstream an anticoagulant hirudin. They are mainly hermaphrodites and belong to the class Clitellata, as they have a clitellum near their gonads, not far from their heads. About 500 of the 700 known species live in fresh water. Leech infestation is common where children are constantly exposed to wetland environments. While local skin attachment is by far the commonest site, leeches sometimes penetrate body orifices and have been described causing disease in places that defy belief, including the eye, nose, larynx, urethra, bladder, vagina and rectum.1 The medicinal leech Hirudo medicinalis has a long and distinguished history.2 Leeches can be seen in ancient Egyptian cave paintings over 3500 years old, at the beginning of what we call human civilisation. Their medicinal use was first documented in a medical poem ‘Alexipharma’ by Nicades of Colophain, who was born in 200 BC. Around the first century AD, descriptions of medicinal leeching appeared in the Arabic, Chinese, Persian and Sanskrit literature. It was the Romans who gave leeches the name Hirudo. The word leech derives from the Anglo-Saxon word laece, a physician, indicating the close tie between leeches and doctors.2 Leeches were farmed and were so popular in the United States and Europe in the early 19th century that there was a shortage.2 But what was the scientific basis of this therapy? The concept of blood-letting as therapeutic may derive from the belief of Asclepius and his Syrian pupil Themisson of Laodicae that evil spirits causing illness could be removed by blood loss. Galen described four bodily humours, blood, phlegm, yellow bile and black bile, which needed to be in equilibrium for good health. If this equilibrium was disturbed, he argued, health could be
restored by blood-letting. Barber-surgeons in the Middle Ages had patients grip a staff tightly, causing their veins to become prominent and easily bled. The bleeding was often done using leeches and blood dripped onto linen bandages. It has been suggested that the image of blood-stained bandages wrapped around the barber’s white pole gave rise to the red and white pole still displayed outside some hairdressing salons.3 The leech was a kinder option than alternative means of blood-letting such as lancets. Why are we so repelled by leeches? Although leeches can carry blood-borne viruses, they have not been shown to transmit them. In contrast, blood-sucking vampire bats are important vectors of rabies. It is interesting to speculate that mythological human vampires could owe their conception to blood-sucking leeches and bats. Many different cultures have ancient myths of blood-sucking creatures, often in human form. In Europe, vampire stories only became really popular in the 18th century, when the name vampire was first used. Despite the widely known legend of Count Dracula, many vampires were women. Doctors increasingly realised that the most effective use of leeches was to decompress inaccessible collections causing problems such as enlarged haemorrhoids or a prolapsed rectum. This more modern use of leeches has seen a modest resurgence over the last 25 years. Microsurgeons have used leeches to salvage skin and flaps compromised by venous congestion.4 As an infectious disease physician, I was intrigued to read that leech therapy is not infrequently complicated by infection with the Gram-negative rod Aeromonas, which can be prevented by prophylactic ciprofloxacin, given either to the patient or put in the leeches’ water. Less commonly but more dramatically, leeches have been used to treat traumatic macroglossia and to improve microcirculation to the hands of children with meningococcal or pneumococcal purpura fulminans. The leech can cause disease in children has been used as therapy of highly dubious efficacy for millennia, but is now being used therapeutically with a slightly stronger rationale. So far, there have been no randomised controlled trials of leeches although, to my delight, a search of the Cochrane library revealed a protocol for a trial of leech therapy for osteoarthritis.5 It will be an inventive mind that comes up with a sham leech for a double-blind trial.
References 1 Hannan MJ, Hoque MM. Leech infestation in children through body orifices: experience in a hospital in Bangladesh. World J. Surg. 2012; 36: 2090–2. 2 Whitaker IS, Rao J, Izadi D, Butler PE. Historical article: Hirudo medicinalis: ancient origins of, and trends in the use of medicinal leeches throughout history. Br. J. Oral Maxillofac. Surg. 2004; 42: 133–7.
Journal of Paediatrics and Child Health 50 (2014) 661–662 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
661
The much maligned leech
D Isaacs
3 Fitzharris L A History of the Barber’s Pole. Wonders & Marvels, 2011. Available from: http://www.wondersandmarvels.com/2011/10/a-history -of-the-barbers-pole.html [accessed March 2014]. 4 Whitaker IS, Josty IC, Hawkins S et al. Medicinal leeches and the microsurgeon: a four-year study, clinical series and risk benefit review. Microsurgery 2011; 31: 281–7. 5 Croft AM, Chandra S, Perez Fernandez GA, Michalsen A. Leeches (Hirudinea) for osteoarthritis (Protocol). Cochrane Database Syst. Rev. 2014; 2: CD010962. doi: 10.1002/14651858.CD010962.
Professor David Isaacs Editor-in-Chief Children’s Hospital at Westmead Sydney, New South Wales Australia
Sunflower, by Sali Tipa from Operation Art 2012.
662
Journal of Paediatrics and Child Health 50 (2014) 661–662 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
