Ticks: The Nasty Little Vampires
Nowt like a nice drop o' blood for lunch.Click thumbnail to view full-size
There's a Suckee born every day!
They're small, but can be deadly
(also see Mites).
Lyme Disease Spreading in the UK
It’s really hard to find anything to like about TICKS. We are immediately predisposed against any creature that only views us as a host to find a blood meal, be it vampire bats, mozzies, fleas, ticks or Count Dracula. We are especially concerned when we also find that taking a few drops of blood is not always the end of the affair, they can also inject us with some pretty nasty disease-causing pathogens as well.
First, ticks are not insects such as beetles or bugs, but ARACHNIDS, the same family as spiders and scorpions. They can confuse us in this regard, because young ticks have only six legs and we know arachnids have eight, which we only find in mature ticks. Ticks are all blood-sucking creatures and feast on the blood of birds, wild and domestic animals, as well as man, especially when their usually hosts are not to be found. They are opportunistic, dropping on us from trees or shrubs or crawling along the ground and climbing from below. We can even become infested with tiny, immature ticks, which invade dwellings, stables or kennels, etc., in huge numbers of many thousands; if not discovered early, they can cause anaemia in farm animals or pets, apart from any other dangerous bacteria or viruses they may be carrying.
Ticks are ECTOPARASITES, which means they are external blood suckers. They can carry a whole hosts of disease causing organisms which can be responsible for Lyme Disease, (More on this follows), Q Fever, Tularaemia, Relapsing Fever, Babeoisis, Ehrlichiosis, Meningoencephalitis and Anaplasmosis in Cattle, as well as Canine Jaundice in dogs.
When a tick lands upon an exposed part of its host, it first cuts an entrance with its Chelicerae, then probes with the Hypostome, its straw if you like. This is barbed to act as an anchor and it is why they are so hard to remove.
Most wild mammals are victimized by one of the many species of tick. This includes lions, moose and deer. (by the infamous Deer Tick). They have few predators themselves, although one remarkable bird, the Guinea fowl, adores ticks and eats them by the bucketful and is able to clear 2 acres of ticks in just one year. A wasp, the Ichneumon Wasp, something of an arachnid specialist, also paralysis ticks and lays its eggs in them. These then feed on the tick’s inert body when they leave the egg in the larvae stage. All ticks are difficult to see or sense, especially the minute young, making them difficult to eradicate. This is compounded by the fact that the substances we do know kills them in swathes, is also very poisonous to the higher animals as well.
Many species of ticks are a nuisance to man and other mammals, They are found world-wide, anywhere the habitat is adequate for their concealment and the supply of blood meals are sufficient.
Australia has 75 species about what little, really, is known; they are called, with typical Antipodean’s succinctness, Australian Ticks. Among them is the Paralysis Tick, (Ioxes Holocyclos), from which most bites are harmless, although some can cause Tick Typhus, or paralysis, (as can 10 cans of Foster’s lager!).
Ixodes (Deer Tick) and the Ixodes Pacificus can be vectors for Lyme and Rocky Mountain Spotted Fever. The Dog Tick can also cause the latter disease.
There is even a “Lone Star Tick,” which may have Texans scratching, but refers to the star mark on its back and has nothing to do with the largest state in the Union. (And it can cause S.T.A.R. disease…google)
LYME DISEASE. (Or Lyme Borreliosis). This has become quite a problem in Europe, especially the British Isles over the last 20 years. (Although is has been with us from Victorian times at least). Indeed, it is the commonest tick-borne disease in the Southern Hemisphere, so requires some attention. The disease gets its name for an outbreak of the then unknown affliction in Lyme Connecticut in 1975. In the UK, the Sheep Tick carries the bacteria.
Lyme is nor contagious and commonly starts as a rash, (Erythema Migrans) after the 2 to 30-day incubation period, spreading from the bite site over 5 to 14 days. This may be accompanied by, or a prelude to, headaches, fatigue and fever. Doctors may recognise the disease and prescribe antibiotics which should clear up the disease in the early stages. Untreated, Lyme can be very nasty indeed, going on to cause abnormalities in organs such as the heart and liver, etc., etc., which may be irreversible and life threatening eventually.
The last set of figures I have is for 2006, when there were 684 cases of Lyme reported in the UK. Many more may well be going untreated as is often the case with these types of diseases and with others, such as Chaga’s, etc., where the symptoms are not always specific. (In fact, the HPA says there may have been 3,000 or more cases that went unreported, unrecognized and untreated in the same year).
Lyme is often hard to diagnose and harder to treat. Once the common signature rash - the Bull’s Eye Rash - is seen, a standard tests, (The Western Blot Test), may or may not detect the bacteria (Borrelia Burgdorferi) in the blood. Some doctors in California, which has reported as many as 16,000 cases a year, say the initial antibiotic treatment is often not aggressive enough as doctors don’t want to over prescribe when they are not 100% sure of their diagnosis.
Two other diseases caused by ticks in the UK and Europe are Babesiosis where red blood cells are compromised as in malaria and Erlichiosis which attacks the white blood cells. Ticks are a greater nuisance during the spring and summer, from May to October. Wikepedia and other sites have full details of these and other tick diseases and are outside the scope of this general information and interest article.
Rocky Mountain Spotted Fever is an even worse tick borne disease. The culprit here is the Demencentor Tick, and the bacteria responsible is the Rickettsia rickettsi. This is an animal disease, (zoonosis) transmitted to humans by the tick vector (go-between). Before the discovery of antibiotics such as tetracycline, etc., up to 30% of victims died from this disease. Even today, as many as 3 to 5% of patients loose their lives. Treatment needs to be prompt with this difficult to diagnose infection. In this case, the rash is secondary to a whole host of symptoms (Wiki). As in all tick infections, the speed with which the tick is detected and removed is important in not allowing the bacteria or virus (Colorado fever, etc.) to enter the host by means of the tick’s saliva. This can take several hours after the blood meal commences.
Removing a tick from you or a pet. The secret is to never press or compress the body of the tick or leave the mouth parts in situ. Also, do NOT use a hot match, a cigarette, Vaseline or other fluids. (This might work for leeches). You have to remove tick gently with a specialist tick tool or tweezers which grasp the tick below the engorged body and gently twist the creature until the barbs disengage from the bite site. (see photo). Then the whole tick can be killed. Tick tools can be found in large pet shops and vet’s clinics.
Other Arachnids: Mites are the smallest and most numerous Arachnids ((subclass Acarina), and have been around since the Devonian period, that ancient time from 360 to 416 million years ago. There are literally millions of species we know and many more we do not. They are everywhere in every habitat, from the sea and the forests, to your bed. Some are beneficial to us and break down decaying matter, etc., some definitely not, causing skin complaints, disease such as a form of typhus, and even aggravating asthma. At this level of miniaturization, not all have 8 legs and the rule book regarding arachnids can be thrown out of the window. It almost seems as if these tiny creatures are bridging the chasm between higher animals and the bacteria and viruses: many of their actions are similar to those of bacteria in fact.