Introduction to Parasitology and Zoology

Parasitology

Area of biology concerned with the phenomenon of dependence of one living organism on another.

Medical/Clinical/Diagnostic Parasitology

It concerns Primarily with the animal parasites of humans and their medical significance, as well as their importance in human communities.

Parasites

Organism/s depending on another living creatures for existence.

Host

Organism that supports or harbors parasite.

Vector/Transmitter

Responsible for transmitting the parasite from one host to another.

Example: Insects, Animals, etc.

Incidence

Number of new cases of infection in a population in a given period of time.

Symbiosis

Living together, the association of two living organisms.

Commensalism

The association between two different organisms in which one benefits and has a neutral (no harm) effect on the other.

Mutualism

Association of two different species of organism that is beneficial to both.

Parasitism

Association of two different species of organisms that is beneficial to one at the other’s expense.

Infective

Parasite that has demonstrated the ability to initiate infection.

Pathogenic

Parasite that has demonstrated the ability to cause disease.

Obligate Parasite

Depend entirely upon their host for existence.

Example: Malaria and Filaria

Facultative Parasite

Exist in a free-living state or may become parasitic when the need arises. Also known as “Opportunistic Parasite.”

Incidental/Accidental Parasite

Attack an Unusual Host

Spurious Parasite

Free-living organisms in nature that are parasitic to others but not in humans.

Ectoparasite

Parasite living outside the body of the host; Will not penetrate into the tissues; Living on the surface of the skin; Infest

Endoparasite

Parasite living inside the body of the host; Living within the body of the host; Infect

Saprophytes

Lives in organic substances in a state of decomposition.

Example: Fungi

Ectoparasite

Type of Parasite, According to its Habitat, known to Infest.

Endoparasite

Type of Parasite, According to its Habitat, known to Infect.

Intermediate Host

Type of host in which the larval asexual phase of parasite development occurs.

Definitive Host

Type of host in which the adult sexual phase of parasite development occurs.

Reservoir Host

Type of host harboring parasites that are parasitic for humans and from which humans may become infected. The organism is inside of it.

Carrier/Humans

Reservoir host with clinical symptoms.

Reservoir Host/Animals

Reservoir host without clinical symptoms.

Accidental Host

Not the usual or preferred host for particular parasites.

Transport Host

Type of host responsible for transferring a parasite from one location to another/harbors underdeveloped stage. The organism is outside of it.

Mechanical/Phoretic Vector

The parasite is only seen on the surface of this organism, and there will be no development of the parasite.

Examples: Cockroaches, Flies, etc.

Biological Vector

The parasite is seen inside the body of this organism, and the parasite needs the organism for its development. Can cause infections.

Examples: Mosquitoes, Tsetse flies, etc.

Exposure

The act or process of inoculation.

Pathogen

Animal parasites which are harmful, frequently causing local and systemic damage.

Incubation Period

Period between infection and evidence of symptoms.

Pre-Patent Period/Biologic Incubation Period

Incubation period pertaining to the time you acquire the organism up to the time that you could get/isolate it into the bodily fluids of an individual (stool, urine, blood, etc.).

Clinical Incubation Period

Incubation period from the time you inhale/ingest the organism to the time clinical symptoms appear.

Autoinfection

When the infected person is his own source or re-exposure.

Superinfection

When an individual harboring a parasite is re-infected with the same species.

Coinfection/Mixed Infection

There are at least two infections in one patient.

Horizontal Transmission

Person-to-person transfer is a common mode of transmission of infectious agents called [—-].

Vertical Transmission

When an unborn baby is infected with a parasite that came from the mother through the placenta, the process of which is [—-]. This may result in congenital infections.

Zoonotic Infections

Parasites that originated from animals are called [—-].

Heterofection

Infections coming from another source of the same species, like human-to-human, is called [—-].

Protozoa

Unicellular; Can perform life processes using their organelles.

Examples: Amoeba and Flagellates

Metazoa

Multicellular; Have organ system that perform complex of life.

Examples: Nematodes, Trematodes, and Cestodes.

Protozoa — Sarcomastigophora — Sarcodina ; Pseudopodia

Sub-kingdom, Phylum, and Sub-phylum of E. histolytica?
What is its organ of locomotion?

Protozoa — Sarcomastigophora — Mastigophora ; Flagella (Hairlike)

Sub-kingdom, Phylum, and Sub-phylum of G. lamblia?
What is its organ of locomotion?

Protozoa — Apicomplexa ; No Organelle of Locomotion

Sub-kingdom and Phylum of Plasmodium?

What is its organ of locomotion?

Protozoa — Ciliophora ; Cilia

Sub-kingdom and Phylum of B. coli?

What is its organ of locomotion?

Protozoa — Microspora ; Spore-forming

Sub-kingdom and Phylum of Enterocytozoa bienusi?
What is its organ of locomotion?

Cyst

Dormant or non—motile form.

Infective Form.

Predominantly found in Semi or Formed Stool.

Trophozoite

Vegetative/Motile Stage.

Pathogenic Form.

Predominantly found in Water Stool.

5-10% Formalin

Chemical used to preserve cysts.

Polyvinyl Alcohol (PVA)

Chemical used to preserve trophozoites.

Conditions that favor Encystation:

1. Overpopulation

2. Significant change in the pH

3. Diminished or too much supply of Oxygen

4. Water Loss

5. Deficiency or Overabundance of food in the environment

Conditions that favor Excystation:

1. Favorable pH of the environment

2. Osmotic Changes

3. Enzymatic Action

Chromatoidal Bodies

Food inclusion bodies that are made of protein.

Proteins

Chromatoidal Bodies are made up of?

Glycogen Mass

Food inclusion bodies that are made of carbohydrates?

Carbohydrates

Glycogen Mass are made up of?

Cytoso(m)e

Cell Mouth

Cyto(p)yge

Cell Anus/Pwet