Lice, fleas, bugs, ticks, body lice [1]

Poux, puces, punaises, tiques, morpions (Parasites humains) [1]

Such trivial tiny beasts : should we be upset ? [Genista]

By Nicolle Mathé, 'Genista Informations' No. 278, November 2001 (Strange animals)

When the evening comes, all the members of the family gather to share a few hours of happiness in the kitchen, the living-room and even the bedroom : the children, exhausted by a day's schoolwork, Wolf the dog and Chloe the she-cat, with their dirty fur, tired for having wandered in the neighbouring streets and gardens. Everyone, with a care for affection, is looking for comforting words and caresses.

But careful !

Don't the fur of pets, hair, clothes, bring home some undesirable clandestine ones, so small that they cannot be seen and that they slip everywhere into clothes, armchairs, carpets and beds ? Are they dangerous for the family ?

Ticks not so common !

An Arachnida belonging to the group of Acarina, the tick is a large ixode with a flat body when it has not eaten, looking like a sphere when it has eaten enough. It is in fact a hématophagus which firmly clings into the slin because of the claws and suckers at the end of its four pairs of legs and the large teeth on their mouth grippers.

tick [tique]

Sting and bite

At the time the tick bites, it inoculates an anti-coagulant saliva et the blood of the bitten host, being liquefied, is est sucked through the pharynx. But, this saliva is, too, rich in bacilli !

The bites can, by themselves, cause serious diseases of the nervous system, such as encephalitis and tick paralyses : a few days after a female tick has settled, a motor deficiency appears in the region of the legs, arms, and then the respiratory muscles. This is because of the injection of a neurotoxin which is fatal for the dog as well as the child, if the female tick is not taken off before the respiratory muscles are affected.

The inoculation of Thrombicula automnalis or chiggers and of Demodex, which lives in hair follicles and sebaceous glands of the face and the sides of the nose, cause unbearable itches.

Other diseases

Tick borreliosis is caused by the inoculation of a spirochete, or helical bacterium called Borrelia burgdorferi and giving Lyme disease, with an exanthema (red blotch) close to the bite then migrating, together with headaches, a recurrent fever with several peaks, pains in the muscles and joints, symptoms of meningitis, des oligo-arthrites, paralysis in the face, lymphocytosis.

Rickettsioses are infectious diseases caused by rickettsiae, a germ between viruses et bacteria, conveyed by the dog-tick. Thus, mediterranean spotty fever is caused by Rickettsia conori with a generalised eruption of macula and papulas (red pimples) and a scab around the inoculation point.

Tularemia, set off by Pasteurella tularensis conveyed by rodents, hares and rabbits, affect children, hunters and cooks, noticeably while while cutting up the animals : after a short incubation, fever stays for over a week, with headaches, stiffness, an big and painful axillary lymphatic ganglion and, at the inoculation spot, a small painful sore looking like a suppurating canker. Known forms affecting breathing and the skin can also be found.

Reproduction

Ticks lay a large number of eggs which give out hexagonal larvae after six weeks. This proliferation makes it difficult to get rid of them.

Go away, you have got scabies !

The one responsible is also an Acarina, called Sarcopte scabiei. Its oval body bears four pairs of legs, the two forelegs bearing suction pads.

The sarcoptid digs galleries in the epidermis of mammals in order to lay inside their eggs which hatch after ten days. It then causes intense itches with skin lesions at the elbows, the armpits, between the fingers, in the folds of the abdomen... those are the scabious furrows or laying galleries, like greyish linear trails and and granulous beads at the end of the furrows. Sometimes these are not visible.

This scabies is very contagious and some types of scabies — that of the dog, cat and horse, for example — can be transmitted to humans.

Good heavens, a bug !

Cimex lectularius or bed bug (house bug) is also a hematophagus which can stay without food for three months and over.

It is an oval, flat, soft insect black or reddish, ²/₁₆ to ⁵/₁₆ inches long (3·5 to 8 mm). Its fore wings are reduced to scales and the back ones are missing. The legs are armed with two sharp claws and a proboscis with a bulging centre bends under the head between the two forelegs.

A light-avoiding insect, the bug bites humans during the night on uncovered parts of the body and, during the day, they shelter in bedclothes, woodwork and curtains. The bites give painful papulas and itches.

The females lay large quantities of eggs (fifteen every day) which hatch after a week. The complete evolution is completed in eleven weeks and, if the temperature is above 15°C, the development is continuous. It is therefore also difficult to get rid of them.

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Part 2 : Tiny ones not so trivial • [Deuxième Partie : Des bestioles plus si banales]

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