The Different Classes of Parasites

Parasites can be grouped into three main categories; protozoa, helminths, and ectoparasites. Among microorganisms that are parasitic there are also viruses, bacteria, and fungi.

Protozoa are single celled organisms. Common parasitic protozoans are amoebas, ciliates, flagellates and sporozoans.

Giardia, a parasitic malady resulting in diarrhea and fatigue, often caught by bathing in polluted waters or drinking through unclean water pipes, as an example, is caused by the protozoa Giardia duodenalis.

Toxoplasma gondii, the most common protozoan parasite in developed nations is said to infect up to 80% of the human population and is implicated in the degeneration of psychomotor function as well as the development of neuroses ranging from indiscriminate risk-taking behavior to schizophrenia.

Helminths are the worms. Flukes (trematodes), tapeworms (cestodes), and roundworms (nematodes) are among the most common.

Ascaris lumbricoides, a species of roundworm, are the most common worms found in the intestines of humans.

Taenia solium, commonly known as the pork tapeworm, is the number one cause of seizures worldwide.

Liver flukes, Fasciola hepatica, cause destruction to the liver in the form of cirrhosis or Cholangiocarcinoma (CCA) a type of cancer, among many other potential threats to the liver and gallbladder during their often long asymptomatic existence.

Ectoparasites are parasites of the skin. An example of this is the mite Sarcoptes scabiei which causes scabies, an itchy pimple like rash on the skin. Chronic spontaneous urticaria, or hives, is a skin manifestation of parasites trying to burst through the biological barrier of the skin. The commonly known “Staph infection” is usually caused by Staphylococcus aureus, a gram positive bacteria (a bacteria with a thick cell wall), that causes pimples, boils and/or red, crusty skin.

One example of a pathogenic fungus in humans is Candida albicans, a yeast-like opportunistic fungus that causes fatigue, headaches, digestive issues and poor memory among many other unique to individual symptoms.

A particularly dangerous parasitic fungus is Aspergillus Niger, known in lay terms as ‘black mold.’ This mold is used to derive the common food preservative in many shelf items, known as citric acid. When individuals live in a home infested with this fungus, which grows on everything from rancid fruits to damp wood, they may experience mysterious health issues such as shortness of breath, confusion, irritability or fatigue.

A well-known virus that acts as a parasite is HIV, human immunodeficiency virus, which attacks white blood cells in a human in order to weaken the immune system so that it can create a tolerable existence for itself inside the body.

Viruses are the parasitic hijackers.

Viruses are the primary causes of cancers as they are intracellular parasites that proliferate malignant cells by hijacking the cell function and hiding under protein coating that render them indistinguishable from other human cells (unless one pays close attention).

An example of a parasitic bacteria is mycobacterium tuberculosis which causes tuberculosis, the most prevalent infectious disease worldwide. A bacteria is similar to a protozoan parasite in being single-celled, but it varies in that it does not contain a cell nucleus.

The four basic shapes of bacteria are Coccus (spherical or ovoid), bacillus (rod-like), vibrio (comma-shaped ), and spirilla (spiral or helical shaped).

Defulsovibrio bacteria are an example of a bacteria that can wreak havoc on the systems of the body. This bacteria is currently implicated as the cause for Parkinson’s disease by influencing α-synuclein through producing hydrogen sulfide which interferes with neuronal signalling.

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