INTRODUCTION TO CLINICAL
PARASITOLOGY
Parasite Categories - answers- Protozoa
- nematodes
- cestoda
- trematodes
Symbiosis - answersTwo organisms of different species living together
- Commensalism
- Mutualism
Commensalism - answersSymbiotic relationship in which the parasite is benefited and
the host is neither benefited nor harmed
Mutualism - answersSymbiotic relationship in which both parasite and host are
benefited
Parasitism - answersSymbiotic relationship in which one organism, the parasite, is
metabolically dependent on another organism, the host; the host may or may not be
harmed in the relationship
Pathogenic parasite: - answersA parasite that harms the host
Facultative parasite: - answersNormally free living organism but may become an
opportunistic parasite
Obligatory parasite: - answersCannot survive in a free living state
Endoparasite - answersA parasite living inside the host
Ectoparasite - answersA parasite living on the external
surface of the host
Host - answersAny living organism, animal or plant that harbors or nourishes another
organism
, Definitive host: - answersThe host that harbors the adult or sexually reproducing stages
of a parasite
Intermediate host: - answersThat host which harbors the immature, larval, or asexually
reproducing forms of a parasite
Reservoir host: - answersA host which replaces man in the life cycle of the parasite
Paratenic host: - answersA host that serves as a transport host in which the parasitic
forms undergo no development, but passes on to the final host
Life cycle- - answersthe process of a parasite's growth, development and reproduction,
which proceeds in one or more different host depending on the species of parasites.
Infective stage- - answersa stage when a parasite can invade a human body and live in
it.
Infective route- - answersthe entrance which the parasite invades the human body.
Infective mode- - answershow the parasite invades the human body.
Vector - answersA carrier, usually an arthropod, which transmits an infective form of the
parasite from host to another
Autoinfection - answersA reinfection in which the host is its own source of infection from
a source already present in the body
Ingestion - answersOral (nasopharyngeal) in food, water or aerosols, etc.
(a) Remains in gastrointestinal tract
(b) Internal migration to other host organs or systems
(c) Migration through other host systems and return to gastrointestinal sites
Active penetration: - answersThrough host tissues, skin or mucous membranes
(a) Remains on or within the epidermis or subcutaneous tissues
(b) Penetrates to other host organs or tissues
Injection - answersThrough host tissues by vector or agent
(a) Arthropod-borne: By mouth parts, salivary glands, or waste products
(b) Transfusion: Present in donor blood at time of transfusion
Congenital - answersTransmission of parasites across the placental barrier from mother
to fetus
Forms of Parasites Studied: - answers1. Adult
2. Larva
3. Egg/Ova
PARASITOLOGY
Parasite Categories - answers- Protozoa
- nematodes
- cestoda
- trematodes
Symbiosis - answersTwo organisms of different species living together
- Commensalism
- Mutualism
Commensalism - answersSymbiotic relationship in which the parasite is benefited and
the host is neither benefited nor harmed
Mutualism - answersSymbiotic relationship in which both parasite and host are
benefited
Parasitism - answersSymbiotic relationship in which one organism, the parasite, is
metabolically dependent on another organism, the host; the host may or may not be
harmed in the relationship
Pathogenic parasite: - answersA parasite that harms the host
Facultative parasite: - answersNormally free living organism but may become an
opportunistic parasite
Obligatory parasite: - answersCannot survive in a free living state
Endoparasite - answersA parasite living inside the host
Ectoparasite - answersA parasite living on the external
surface of the host
Host - answersAny living organism, animal or plant that harbors or nourishes another
organism
, Definitive host: - answersThe host that harbors the adult or sexually reproducing stages
of a parasite
Intermediate host: - answersThat host which harbors the immature, larval, or asexually
reproducing forms of a parasite
Reservoir host: - answersA host which replaces man in the life cycle of the parasite
Paratenic host: - answersA host that serves as a transport host in which the parasitic
forms undergo no development, but passes on to the final host
Life cycle- - answersthe process of a parasite's growth, development and reproduction,
which proceeds in one or more different host depending on the species of parasites.
Infective stage- - answersa stage when a parasite can invade a human body and live in
it.
Infective route- - answersthe entrance which the parasite invades the human body.
Infective mode- - answershow the parasite invades the human body.
Vector - answersA carrier, usually an arthropod, which transmits an infective form of the
parasite from host to another
Autoinfection - answersA reinfection in which the host is its own source of infection from
a source already present in the body
Ingestion - answersOral (nasopharyngeal) in food, water or aerosols, etc.
(a) Remains in gastrointestinal tract
(b) Internal migration to other host organs or systems
(c) Migration through other host systems and return to gastrointestinal sites
Active penetration: - answersThrough host tissues, skin or mucous membranes
(a) Remains on or within the epidermis or subcutaneous tissues
(b) Penetrates to other host organs or tissues
Injection - answersThrough host tissues by vector or agent
(a) Arthropod-borne: By mouth parts, salivary glands, or waste products
(b) Transfusion: Present in donor blood at time of transfusion
Congenital - answersTransmission of parasites across the placental barrier from mother
to fetus
Forms of Parasites Studied: - answers1. Adult
2. Larva
3. Egg/Ova
