The word ‘parasite’ takes its origin from the Greek word ‘parasitus‘ which refers to ‘a person who eats at another’s table’.  The word parasite, biologically speaking, refers to an organism which lives at the expense of another living organism. Thus the very existence of a parasite is dependent on the latter which is technically known as the ‘host’.

Parasites come in different shapes and sizes and. While some may be so small that you need a microscope to see them, there are others which are visible to the naked eye. An example of the former would be the influenza virus. The tapeworm could be an example of the latter.

A parasite can be an ectoparasite or an endoparasite. An ectoparasite is a parasite that lives outside the body of the host. Examples of ectoparasites are the head lice or the flea. Similarly the Sarcoptes scabie, the mite which causes skin rashes known as scabies, is an ectoparasite as it affects the external part of the body of the host, the skin. Unlike in scabies which is caused by an ectoparasite, an endo parasite, on the other hand, lives inside the body of the host. An example of this is the virus that causes malaria.

Parasites are not confined to the animal kingdom alone. Parasites are to be found in the plant kingdom also. As far as the plant kingdom is concerned, the largest number of parasites is to be found in the group called the ‘Fungi’. In the animal kingdom, parasites are spread among the following groups – insects, worms, mites, ticks etc.

Parasites are usually transmitted by a variety of modes such as contamination of food, water or feaces. Apart from these modes there are other modes as well. For instance, Scabies spreads through skin-to-skin contact or through sexual contact with an infected person.

Scabies may also spread through the use of personal linen, clothes etc. used by an infected person. At times the parasite may need an intermediary to aid transmission. This intermediary is called the carrier. For instance, in the case of the malaria, the parasite namely, Plasmodium resides in the mosquito and through its bite is transmitted to humans. Thus the mosquito becomes the carrier of the parasite.

When a parasite takes over a human body, it manifests itself by means of the following symptoms:

  • You may become anemic due to the nutrients from the food you ingest being taken away by the parasite. The person becomes weaker and weaker and there could be perceptible loss of weight.
  • You may have intense itching all over the body, which is more pronounced during nights. (This is a typical symptom of Scabies.)
  • You may complain of constipation due to blocking of the colon.
  • You may have a bout of diarrhea
  • You are likely to feel fatigued
  • You may have flu like symptoms.
  • You may have stomach pains
  • Bloating of the stomach and gas formation is also possible.
  • You may have skin rashes, which due to scratching may give rise to sores. This is another symptom of Scabies

Getting rid of the parasite from the human body is a challenge. The human immune system itself is capable of getting rid of the parasite by throwing the parasite out by means of vomiting, diarrhea etc. Fever, incidentally is a symptom that tells you that you have been infected by a parasite.

A battery of laboratory tests is available which can confirm the same and also help your doctor zero-in on the exact strain of the parasite so that he can prescribe the correct medication to help you get rid of the parasite. For instance, diagnosis of Scabies infestation is made by examination of burrows in the skin or rashes. Confirmation of scabies infestation may be done by biopsy of skin scrapings.

Treatment varies depending upon the infection. For instance, the treatment for scabies is done through the application of lotions available in the market for the treatment of scabies.

Given below is a list of parasites which affect humans:

  • Giardia duodenalis
  • Cryptosporidium arum
  • Cyclospora cayetanensis
  • Toxoplasma gondii
  • Trichinella spiralis
  • Mania Saginaw
  • Taenia saginata
  • Malaria parasite
  • Sarcoptes scabiei( causes scabies)

Prevention is better…

To prevent being infected by parasites, the set of simple rules given below should help:

  • Consume water that has been boiled and then cooled
  • Wash your hands after playing with pets, particularly those that are ill.
  • Avoid pools which are commonly used, to avoid probable infection
  • Use pasteurized milk
  • Use vegetables and fruits after washing
  • Cook all animal products including meat etc well before consumption.
  • As stagnant water is an easy breeding ground for mosquitoes eliminate such pools