What is a parasite?
The definition of a parasite.
The definition of a parasite is an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense. This however does not always mean that the parasite harms its host, some parasites only benefit its host in fact. There are many parasitic worms that actually benefit our imune system and therefore making us healthier. As bizarre as that may sound, parasites are not all evil and scary as they are portrayed (especially in a quick google search for images of parasites). Unfortunately this is not the case for all parasites, but we will be discussing both kinds to give you a complete guide to what a parasite is.
What is a parasite?
Parasites are eukaryotic organisms (bacteria are prokaryotes) belonging to the animal kingdom and are roughly divided into the following groups:
single-celled parasites (protozoa)
worms (helminths; plathyhelminthes of flatworms including the flukes and Cestoda; of roundworms Nematoda)
arthropods (eg mites, ticks, lice, fleas).
The single-celled (unicellular) parasites and worms live in the human body (infection) and are therefore called and endoparasites. Most arthropods such as mites, lice and fleas from living on the skin and are therefore also called ectoparasites. Host The host is a grouping in which the parasite lives. The parasite can change during its life cycle of host. A distinction is made between parasites die and parasitize a host species (monoxeen) and host species of parasites that can change (heteroxeen, eg Taenia saginata tapeworm die for the life cycle depends on both man and cattle). In addition, a distinction is made between hosts in which the asexual multiplication of the parasite takes place (between hosts) and hosts in which sexual reproduction / development of the parasite occurs (final host).
A large number of parasites that infect humans are also found in other animals. These animals (hosts) can therefore act as a source of infection for humans, we speak of reservoir hosts. Transmission Transfer (transmission) of parasites from one host to another can be done in several ways. Example, by direct (physical) contact between hosts (eg fleas, mites, lice), by eating meat (eg tapeworms) of fruit (fox tapeworm) that parasites, larvae from eggs of parasites through contact with pets ( eg toxoplasma). Some parasites, protozoa mainly but also worms are transferred door invertebrates such as mosquitoes, flies and ticks. These are the vectors of the parasite.
Commensal parasite whose host is at no (proven) disadvantages. Many examples of commensalism are known as parasites of humans, most evident in parasites that live in the intestines (eg amoeba Entamoeba coli). Parasites in humans in the tropics and subtropics Parasites come in greater numbers and greater diversity than in the temperate and cool regions of the world. Under the tropical infectious parasitic infections take place in a dominant (eg malaria and schistosomiasis). The number of people infected at any given moment is for the different parasite species between tens and hundreds of millions (eg ascaris more than one billion infected with malaria, which in Africa alone more than one million children a year die).
Infections with parasites
The percentage of people infected at some point a certain parasite, the prevalence of infection known. Many infections with parasites expired without (obvious) symptoms. The percentage of infected people that have clear clinical symptoms (without the infection to death) and morbidity is called. Mortality, the percentage of infected people who dies as a result of an infection. In the Netherlands, parasitic infections are less frequent and infections with viruses and bacteria take an important place among the infectious diseases. Some parasitic infections that occurred earlier in the Netherlands, such as malaria, have disappeared from the Netherlands and can no longer be incurred Netherlands.
There are still a number of parasitic infections in the Netherlands which the prevalence is high, such as that of Toxoplasma, Trichomonas, Enterobius (anus made) and Pediculis (lice). So there is every reason to be attentive to the Netherlands Parasitic infections. Parasitic infections occur in nature in the Netherlands called for endemic infections. Many parasitic infections in humans in the Netherlands are caused by parasites that do not occur but which are incurred abroad, called input infections. An increase in imports of these infections in the Netherlands and this is due to the increase in international travel. Migrants, migrant workers, asylum seekers, adopted children, tourists and those in their profession for family matters visiting an endemic area may carry parasitic infections and the Netherlands.
Not endemic to imported diseases includes malaria, amoebic dysentery and many worm diseases. The increase in imports is not only infections caused by an increase in passenger traffic. Also increased (transmission) of parasitic infections in the tropics and development of drug resistance, such as malaria, may be a cause. Imported infections are of great importance for the patient and the physician seldom or never find the parasite introduced here favorable conditions for diffusion. Travel in the tropics and Parasites Many parasitic infections are acquired by travelers to the (sub) tropics, such as malaria and schistosomiasis. There are currently no effective vaccines against parasitic infections.
To avoid incurring a number of parasitic infection during the stay in the (sub) tropics are effective (and simple) measures, such as taking malaria prophylaxis and sleeping under a mosquito net against contracting malaria infections avoid water contact in Africa where schistosomiasis occurs.
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