Clinical Parasitology: Human Parasites Classification

Questions and Answers

Which of the following classifications of human parasites is known for exhibiting pseudopodia?

Trematoda

Cestoda

Sarcodina (correct)

Mastigophora

What type of parasite cannot survive outside of a host?

Obligatory parasite (correct)

Endoparasite

Facultative parasite

Ectoparasite

What is the term for a parasite that remains on or in the body of the host for its entire life?

Permanent parasite

An ectoparasite is established inside of a host.

False Signup and view all the answers

Which term refers to the relationship where two organisms coexist, with one benefiting while the other is harmed?

Parasitism Signup and view all the answers

What is known as the period between infection and evidence of symptoms?

Incubation period Signup and view all the answers

A transport host is primarily responsible for establishing an infection.

False Signup and view all the answers

What term describes a parasite that is found in an organ that is not its usual habitat?

Erratic parasite Signup and view all the answers

What is the term for the individual that can transfer a parasite but does not show symptoms?

Carrier Signup and view all the answers

Study Notes

Classifications of Human Parasites

Protozoa: Classified by motility into four classes:
- Sarcodina: Movements via pseudopodia, sluggish.
- Mastigophora: Motile by flagella.
- Ciliophora: Movement through cilia.
- Sporozoa: Non-motile.
Nematoda: Two main subcategories based on chemoreceptors:
- Phasmidea/Aercentea/Phamids: Contains caudal chemoreceptors located at the posterior end.
- Aphasmidea/Adenephorea/Aphasmids: Possesses cervical chemoreceptors at the anterior.
Platyhelminthes: Segmentation differentiates types:
- Cestoda: Multiple segments; categorized into two orders based on uterine pore presence.
  - Pseudophyllidea: No uterine pore.
  - Cyclophyllidea: Uterine pore present.
- Trematoda: One segment or unsegmented.
Arthropoda: Function as vectors, with classes including:
- Insecta: Characterized by wings.
- Arachnida: Defined by legs.
- Mollusca: Identified by shells.
Pentastomids: Known as tongue worms.
Acanthocephala: Referred to as thorny-headed worms.

Parasite-Host Relationships

Types of Parasites:
- Obligatory: Cannot survive outside of a host.
- Facultative: Can exist independently and become parasitic if needed.
- Endoparasite: Lives inside the host.
- Ectoparasite: Lives on the exterior of the host.
- Erratic: Found in an unusual organ for the species.
- Permanent: Lives on/in the host for its entire life span.
- Temporary: Interacts with the host for a brief period.
- Spurious: Free-living, passes through the digestive tract without causing infection.
Types of Hosts:
- Accidental: Hosts that are not the usual for the parasite.
- Definitive: Where the adult sexual phase of the parasite occurs.
- Intermediate: Hosts where the larval asexual phase takes place.
- Reservoir: Hosts harboring parasites that can infect humans.
- Transport: Transfers parasites from one host/location to another.
- Carrier: Hosts that harbor parasites without showing symptoms.
- Vector: Arthropods that transmit parasites; can be biological or mechanical.

Parasite-Host Relationship Terms

Symbiosis: Interaction between organisms of different species.
Commensalism: One species benefits while the other remains neutral.
Mutualism: Both species benefit from the interaction.
Parasitism: One species benefits at the expense of another.
Pathogenicity: Capacity to cause disease.

Terminology Relating to Exposure and Infection

Exposure: Inoculation of an infective agent.
Infection: Establishment of an infective agent within the host.
Incubation Period: Time from infection to symptom development.
Pre-patent Period: Duration until evidence of infection is observable.
Autoinfection: Infected individual serves as their own infection source. Notable examples include:
- Enterobius vermicularis: Hand-to-mouth transmission.
- Capillaria philippinensis: Internal reproduction.
- Hymenolepis nana: Transmission noted.
- Strongyloides stercoralis: Self-inoculation potential.
Superinfection: Hyperinfection occurring in an already infected individual by the same species, leading to a more severe parasitic load.

Description

This quiz covers the classifications of human parasites, focusing on protozoan groups based on their motility. Participants will explore the four main classes of protozoa and their characteristics. Test your knowledge on clinical parasitology and improve your understanding of these essential biological classifications.