Parasites

A parasite is an organism which engages in a non-mutualistic relationship with another organism, by living either on or within this organism, and experiences an increase in fitness at the expense of the host organism. Parasites can reduce the fitness of their hosts in a multitude of ways, such as by impairing their secondary sex characteristics.

In order to function, in terms of growth and reproduction, a parasite is completely dependent on its host. It is important to mention here that a parasitoid is not the same thing as a parasite. Rather, a parasitoid is a different type of parasite which eventually kills its host once developed. Conversely, parasites rarely kill their hosts.

Parasites come in many forms including bacteria, viruses and protozoa for example. The term parasite generally refers to organisms such as bacteria, which are able to be transmitted throughout the same species. These are known as microparasites.

On the other hand, there are also macroparasites, which are slightly larger in size in comparison to microparasites. These include protozoa for example. Macroparasites are parasites which require multiple host organisms throughout their lifetime as they experience different life stages.

Furthermore, within the parasite category there are multiple different classifications which are dependent upon the particular life cycle of a parasite and its subsequent host interactions. For example, endoparasites are organisms which live within their host’s cells, with intercellular parasites taking up cells within the host organism’s body and intracellular parasites invading cells on the outside of the host’s body.

Parasites are interesting organisms which are not representative of a specific type of organism, but rather a specific lifestyle. Parasites are an important part of all ecosystems and the feeding relationships which take place between species. Therefore, understanding their complexity is important.

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Human Parasites

What are the types of organisms that can cause parasitic diseases in the human being? Explain at least four such organisms. What are the different routes that pathogenic protozoans can use to enter the host cells? What are three methods for establishing a laboratory diagnosis of an intestinal parasitic infection? Explain

Parasites in patients

Please refer to the attached case study. 1. Why might the physician suspect that parasites could be a possibility in these patients? 2. What parasites might the physician have suspected? 3. How should stool culture for routine bacterial pathogens be processed? Be sure to include appropriate media and atmosphere of incubati

Parasitic Protists

Parasitic flagellates may occur in water and damp soil. Provide advice to someone traveling in a third world country as to what foods and drinks it would be wise to avoid and as to which food preparation methods might make foods safe to eat or drink.

Parasitic life cycles in relation to human infection

Using the life cycle, environmental factors and risk factors, what interventions will help prevent human infection with the following parasites: Echinococcus granulosus, Toxoplasma gondii, and Trichinella spiralis?

Which parasite may have caused this disease, how was it transmitted and how do you prevent it?

A girl developed generalized seizures. A CAT scan revealed a single brain lesion consistent with a tumor. Biopsy of the lesion showed a cysticercus. The patient lived in South Carolina and had never traveled outside the state. What parasite caused her disease; How is this disease transmitted; How might it be prevented