12 Jul Thicks?

 
 
 
An invasion of ticks?
  
More and more often, climbers returning after a day at the crag or bouldering find, often in the most unlikely places, these small and unwelcome blood-sucking animals, so much so that the word “invasion” has started to be used.
 
In this article, an expert gives us a picture of the situation and some useful advice.
 
By Simone Manzocchi
 
Ticks, even though they are undoubtedly interesting, are not very popular, given their nasty habit of burrowing into our skin and sucking our blood. In addition, and unlike other parasites such as fleas and mosquitoes, ticks remain attached to our bodies for days on end, so we can watch with disgust the little bastard as it feeds on us.

With the arrival of summer and the increase of temperatures and humidity, lots of creatures wake up from their winter torpor and start their frenetic activity: the bees buzz from one flower to the next, the butterflies flutter up and down the meadows, and the famished ticks set about waiting for their unlucky hosts!
 
In academic language, ticks are “hematophagic ectoparasites”, that is, animals which survive by sucking the blood from the outside of the bodies of other animals. They are arthropods, like insects and crustaceans, and are part of the arachnid family, together with their cousins such as spiders, scorpions and mites. The ticks are divided into two main families, hard ticks and soft ticks, which in turn are subdivided into many genera and species, with different ecological characteristics, preferred hosts, periods of activity and “diseases” transmitted.
 
The tick which climbers and walkers are most likely to come across, especially in woods, is Ixodes ricinus, also called in Italy the wood tick (zecca dei boschi) or the hooved animals’ tick (zecca degli ungulati). This nice little beast is found throughout Europe, including Italy; it lives in woods below 1200 m altitude, particularly in areas well-covered with broad-leaved trees, and shrubs, bushes and ferns, and with high humidity (for example, near to water courses or where rain water collects). A large presence of wild hooved animals (such as deer) raises substantially the tick density, because these mammals are a walking buffet for the parasites.

Ixodes ricinus is most active in the spring and summer, in the months of May, June and July, although, with favourable temperatures, you can come across ticks from March to October. Its life cycle has three phases: larva, nymph and adult. In each one of these stages, when it is active, the tick goes in search of a prey and, when it finds it, feeds on it for a single long meal, and then lets go and falls to the ground where it changes into the successive stage.
 
During the winter the tick seeks shelter in cracks in the ground and remains in a quiescent state (diapause). The larvae are yellow and almost invisible to the naked eye (0.5 mm), the nymphs are yellowy-brown and about 1 mm long, while the adults are reddish-brown and about 3 mm long. In central Europe, the life of Ixodes ricinus lasts on average 3 years, one for each stage of the life-cycle, but this can vary according to temperatures. When the tick is active (and not in diapause) it spends most of its time waiting for prey under the leaves of bushes and shrubs and, as soon as it smells or feels the heat and movement of a passing mammal or bird (or possibly also a reptile), it lets go of the vegetation and grabs onto the fur or clothing of its unwary future blood donor.
 
The arrogant little thing then climbs up the fur or clothing until it finds a quiet, welcoming place (for example, a human’s groin) where it can bury its head and feed. Each of the three stages “hunts” at different heights: the larvae more or less at ground level, the nymphs between the vegetation and the ground and the adults on vegetation up to 1.5 m. The hunting elevation is strictly linked to the type of prey sought, that is small mammals (voles, mice, shrews, hedgehogs) for the larvae; wild hooved animals for the adults; and almost any vertebrate (including humans and dogs) for the nymphs.
 
 The tick’s bite isn’t painful, since its saliva contains a cocktail of anti-inflammatory, anti-coagulant and vasodilatory substances. The tick, once it’s attached to the skin, takes its time and remains attached for a long period, from several days up to a week, sucking blood and digesting the red blood cells and nutrients. The watery part of the blood, on the other hand, is excreted through the secretions from the salivary glands and is literally “spat” into the host, together with the pathogenic microbes from the tick’s body.
 
We have all, at least once, coming home after a nice day out, found one of these animals attached to us, snuggled happily into our skin. If it was only the fact that the tick tastes us every so often, we wouldn’t bother too much, but it’s the sucking and spitting out that can transmit several unpleasant diseases. In Italy the tick transmits Lyme disease and TBE (tick-borne encephalitis).

Lyme disease is an infectious disease caused by the bacteria Borrelia burgdorferi. It is present throughout Europe and in the north of Italy and transmitted to humans by the tick Ixodes ricinus. The parasite acquires the infection in the larval stage when it takes blood from a small mammal or bird which carries Borrelia, a so-called reservoir, and re-transmits it to hosts of the successive stages of the life cycle (nymphs and adults), among them human beings. The typical symptoms are a rash (reddening of the skin), circular in shape, which expands in a circle, to create a round red halo. This appears a few days after the bite and after a few months disappears. Often people with this skin rash aren’t aware that they’ve been bitten by a tick and think that they have an allergic dermatitic skin rash, but usually doctors recognise this symptom and can easily diagnose the disease.
 
Lyme disease can also present with a bluish nodule, called a skin lymphocytoma, on the lobe of the ear, nipples or scrotum. Successively there may be joint pains, with swelling, which generally appear and then disappear a few days later before coming back after a short period in a different joint. Sometimes there are neurological effects, of which the principal ones are paralysis of the facial nerve and a state of sleepiness, memory loss, and inability to correctly coordinate movement associated with a form of encephalopathy. Lyme disease, in most cases, can be cured with antibiotics in 14-60 days (but chronic forms may require 30-60 days’ treatment).
 
A few simple steps allow you to avoid Lyme disease. First of all, when walking, it’s good to dress correctly, in particular if you will be walking in long grass or between bushes. The ideal is to wear long trousers and boots, or clothing that doesn’t ever leave legs and socks exposed, from which ticks can climb up to the groin. Repellents based on deet (N,N-Diethyl-meta-toluamide), applied to the skin and clothes, are useful to repel ticks; they may climb onto our clothes, but it’s unlikely they’ll try to bite us. As soon as you get home, after a nice shower, check out your entire body to find any “little friends” stuck to the skin.
 
It’s very unlikely that Ixodes ricinus transmits the bacteria in the first 24 hours attached to the skin, so if we find a tick on us, it’s very important to extract it as soon as possible. Tick-borne viral encephalitis (TBE) is a disease with two stages: the first flu-like with a fever usually less than 38° with headaches and pains in the spine and joints which gets better in about a week; a second phase which affects the central nervous system with very high fever and symptoms similar to meningitis.
 
There are many old wives’ tales about removing ticks. The only correct way is to grab it with tweezers at the base of the “head” (capitulum), as near as possible to our skin, and pull gently. Never grab the tick by the body because it can easily break and, above all, never apply trementina, acetone, petrol, alcohol, disinfectants or other substances to the tick; they don’t help at all to extract it and make the parasite “spit”, injecting the entire contents of its salivary glands (including any bacteria and viruses) into the host; in other words, the damage that the tick by itself hadn’t yet achieved gets caused by our actions.
 
Another urban legend regards leaving the “head” in the skin. Some say this can cause “serious infection” and I have even heard that the tick can grow again from the detached “head”! If the “head” breaks when the tick is being extracted, this is absolutely not a problem. In fact, what remains in the skin isn’t the head, but a barbed needle with which the tick hangs on, called the ipostoma. Obviously it doesn’t cause any “serious infection” and you can easily remove it as you would a splinter.
 
After removing the tick, you should disinfect the area and keep an eye on it for two months, to quickly identify a rash should one form. After tick removal, if there are no symptoms, use of antibiotics is categorically not advised: antibiotics could mask the rash without eliminating all the bacteria, which would continue to multiply in the body until they cause serious symptoms which you could have difficulty diagnosing as Lyme disease.
 
For our dogs, big and small, you can buy antiparasite collars which use pirethroids (permetrina; deltametrina) and “spot on” products (drops to apply to the pet’s back) based on imidacolprid or fipronil; they can be used separately or together and guarantee a certain degree of protection from infestations. For dogs, as well, it’s advisable to check fur and brush them after a walk in the woods, to avoid bringing ticks into the domestic environment.
From number 13 of the magazine Montagne Divertenti with the kind permission of the author and publisher.