A short news item published in 1843 by the Gazette Médicale de Paris contains the sort of case that would give a hypochondriac sleepless nights. It was submitted by Jean Guyon, an eminent military surgeon who spent much of his career studying tropical diseases, in particular yellow fever and cholera. Another of his interests was the leech – not so much for its therapeutic uses, but as a human parasite.
M. Guyon sent the Secretary a new paper on the Haemopis vorax, on which he has already addressed the Academy. This is a leech which is found in all the springs of Africa, and which infects many of the people and animals which come there to quench their thirst.
This species, whose modern name is Limnatis nilotica, is also known as the horse leech. In his earlier presentation to the academy Guyon showed how he had found the creature in the mouths and throats of a variety of larger animals, including cows, horses, rabbits, birds and humans.
M. Guyon has already had occasion to observe that this leech can establish itself on all the mucous membranes. The vaginal mucosa was the only one on which he had not yet seen it, when the following event came to his knowledge.
This does not sound good.
A woman living in Bone had, for about three weeks, suffered a haemorrhage which her physician referred to as ‘uterine loss’, and which he treated accordingly. This complaint grew worse every day, while the patient was growing weaker. In the meantime she moved to a new home in Algiers. This was in the last days of last April. The loss continued in Algiers, in spite of all the means employed, when Dr. Lebrun, one of M. Guyon’s colleagues, was called; the patient was then excessively weakened, lean and pale. Among the new means advised by H. Lebrun were injections of water and vinegar, repeated several times a day.
These injections made into the vagina (a douche), rather than through the skin or into a blood vessel. Not usually an advisable measure with an agent like vinegar, which would alter the delicate pH inside the vagina; but in this case it seems to have done the trick.
On the fourth day of this treatment, the patient noticed a living leech in her undergarments.
Oh dear god.
The next day, which was the 15th of last month, all discharge had ceased, and it has not reappeared since. The patient now enjoys the best health.
The obvious question now was how the hell a leech had managed to get there in the first place. The patient had no idea.
It is probable, adds M. Guyon, that it entered by means of water which contained the annelid, and which the patient had used in the form of bath or other ablution.
This sounds plausible enough, especially if the bath water was drawn from a cistern rather than from a tap.
The leech has been retained and sent with this communication. It is barely half grown. It is, as we know, in its very early stages, when it is still only threadlike, that the annelid insinuates itself inside the human body, as in animals, in order to live as an internal parasite.
Glad we’ve got that sorted out. The horse leech, which is found in southern Europe and northern Africa, can grow to quite a size; goodness knows what it would be like to harbour a fully-grown one. If you’re a hypochondriac, my apologies and good luck getting to sleep tonight.