Parasites are living creatures that keep themselves alive at the expense of other organisms (the host). Parasites occur on almost all organisms: humans, animals and plants. Some parasites cause the host to perish, others only take small amounts of what they need. In this article I discuss four parasites that affect humans: lice, fleas, bed bugs and ticks.
Lice
Lice are small parasites. They are about 3 millimeters long and have a brownish color. They have three claws on the front of their body that allow them to move easily. In humans, the louse is most common as head lice or pubic lice. The head lice lives between the hairs on the head where it feeds on the blood that is under the scalp. The louse obtains this blood by poking a hole in the scalp with its piercing muzzle. After the sting, the louse brings in some saliva, so that the blood does not immediately clot. The louse can continue to drink like this. This saliva can cause an allergic reaction, causing the host to itch. When there are several lice on the head, the louse will reproduce. This process is very fast, the louse lays its eggs (nits) very quickly in succession. She can lay about 10 per day. During her entire life, the number of nits can reach 100.
The eggs are glued to the hair, just above the scalp.
The pubic lice is not located on the head but in the pubic area. Yet this louse has also been discovered between the eyelashes, on beards or on chest hair. Both types of lice spread very quickly. When there is contact between two people, the lice jump over to the other person. The louse can also be transmitted through clothing or hugs that are in contact with each other. If someone is infected with lice and has discovered it, treatment should be initiated as soon as possible.
Fleas
More than two thousand different types of fleas have been reported on Earth. The flea can only live on warm-blooded animals with hair or feathers. The cat flea is most common in the Netherlands, this type of flea can also live on humans. Furthermore, the Human flea is still rare in the Netherlands, but in other countries such as Africa this flea is very common. Bird fleas also sometimes feast on human blood, but this species cannot live long on a human body. Fleas are tiny creatures, about 3 millimeters in size, that live off the blood of their host. Fleas move by using their long hind legs, which they can use to make big jumps. Fleas, like lice, sting the host to suck up blood. These stings can cause bumps on the host that can be very itchy. These bumps occur all over the body, which shows that the flea is also hiding everywhere.
Fleas lay very small eggs, they are barely visible to the human eye. The flea does not make any effort to store its eggs, they are scattered here and there. The cat flea can lay more than 1000 eggs during its lifetime, that’s around 50 a day. Fleas can be very annoying to humans, but these bugs often cannot survive long on a human body. The flea larvae do not yet drink blood and therefore have to live on other organic material, such as the feces of adult fleas. Larvae are therefore often found in animal nests, humans do not have these and therefore these animals cannot maintain them for long.
Bed bugs
The bed bug gets its name from the place where it is most commonly discovered in the house, in the bed. Bed bugs are about 6 millimeters in size and have a reddish brown color. The bed bug also feeds on human blood that it sucks up through its suction snout. She uses a narcotic anticoagulant to keep the blood from clotting. This causes annoying bumps, resembling mosquito bites, that are very itchy. It usually takes a long time for the bumps to disappear. The bed bug can survive for a long time without food, a few months is no exception. They usually hide between the sheets, in the folds of the bed or under the mattress. Bed bugs are attracted to warm, exhaled CO2 or body heat. For years they thought themselves free from bed bugs in the West, unfortunately this nasty little creature has reappeared more and more in recent years. Fortunately, the bed bug does not transmit diseases.
Sign
Ticks work differently from the parasites discussed above. The tick bites itself in the host, this can be a human or animal, and remains here for a few hours to a few days. The bite of the tick is generally not noticeable, although it can occasionally itch. The most famous tick in the Netherlands is the Sheep tick, which can transmit Lyme disease to its host. When a tick has not yet sucked up blood, it is a few millimeters in size, later, after or during the bite, the tick is much larger and easy to spot. Unlike most other parasites, ticks can get very old. They can go without food for months, sometimes even years, and wait patiently for their host to pass by. When the time comes, the tick jumps on its host and searches for a good place for a while, where the tick then bites. When a tick is removed or released itself, one must keep a close eye on the bite site. If a red ring develops around the bite after a few days, the victim may have contracted Lyme disease.