The lower parts of the Everest trek pass through rather humid parts of the land. Vegetation and fog abound there, creating a haven for leeches; passing trekkers transform this haven into a real heaven for these obnoxious creatures: pleasant climate and easy meals. Knowing how they work and what can be done is essential for ensuring a safe and satisfying trek.
In two different occasions I fed leeches. The first was near Lamjura Pass and by far was the most dramatic. Despite the fog and the altitude, it was a rather hot day, thus I let my T-shirt over my belt so that sweat would evaporate more easily. My two backpacks left very few evaporation spots available and I was determined to use every available inch; climbing up was truly exhausting. I was too new to the scene to understand my error. My action had left a very comfortable opening for a leech. Expectedly, one of them found a comfortable spot on my stomach. Unable to see the parasite, I wasn’t aware of the event. The leech detached itself after the meal was over and I never saw it.
That’s one of the peculiarities of these beasts. Leeches release an anesthetic to prevent the trekker from feeling its biting jaws, so if they attach themselves on a spot which cannot be seen by the victim, they’ll enjoy a quiet and prolonged meal. Once attached, they secrete an anti-clotting enzyme, hirudin, so that the wound continues bleeding, allowing it to suck the blood easily. The effect of this anticoagulant can last several hours, which in certain cases can be worrying.
Later – and for obvious reasons I cannot be specific on the time - I entered a teahouse for a short break. After putting my backpacks on the ground, I found the lower part of the T-shirt was red with blood and that I had an open wound on my stomach. Since the stomach moves while walking, the wound couldn’t close; that happened only after I pressed on it for a while sipping my tea. The only thing to do after the bleeding stops was disinfecting the area and bandaging it lightly; the place healed in a few days and left no marks.
The second occasion was more visual in nature. Near Kharikhola I found a leech on the inner side of my right wrist, it was on the process of attaching itself. I shook my hand and the mighty predator was left on the ground, where it began a hysteric attempt to run away from me. Yet, we shared the same blood; thus sparing it was the only viable solution
My shaking it away is not a standard way of detaching a leech; it worked only because the jaws weren’t still properly attached. The wound hardly bled this time and in a few minutes there it was difficult to even see the spot. Those facing such an event for the first time may be tempted into pulling away the fat worm; however, that’s an error. Its jaws will break apart and that may break the host’s skin in an unclean way (in contrast, regular jaw-cuts look surgical). Such irregular cuts may cause an infection since leeches can carry a variety of bacteria, viruses, and parasites from previous blood sources; these can survive within a leech for months, and may infect subsequent hosts. In order to avoid that, the most popular way of detaching them is with the help of salt. Just pour a few grains next to the jaws, and the beast would jump away in disgust (apparently they worry about their blood pressure…).