Parasitology

Parasitology 1.1

Symbiosis

close union of two dissimilar organisms (living together in intimate association)

Mutualism

interaction between two or more species where each species has a net benefit (+, +)

Commensalism

association between two organisms where one benefits and the other derives neither benefit nor harm (+, 0)

Parasitism

relationship between species where one organism (parasite) lives on or in another organism (host) causing it some harm and is adapted structurally to this way of life (+, -)

Facultative Parasite

may resort to a parasitic lifestyle but does not rely on host for completion of life cycle

Obligatory Parasite

cannot complete its life cycle without relationship with suitable host

Endo-parasite

parasite that lives within a host and causes an infection

Ecto-parasite

parasite that lives on a host and causes an infestation

Definitive Host

supports the adult or sexually reproductive stage necessary for parasite survival

Intermediate Host

supports the immature or non-sexual reproductive forms that are necessary for parasite survival.

Transfer Host

can move or relocate parasite stages from one location to another

Vector Host

transfers parasite to the next host. acts as a definitive or intermediate host

Reservoir Host

serves as a source of infection and potential reinfection of humans. sustains a parasite within a population/ecosystem

Exposure

being in contact with an infectious organism

Colonization

presence of infectious agent on/in a body surface without causing disease in the person

Infection

invasion and growth of infectious agents germs on/in the body

Sign

any objective evidence of disease that can be observed by others (e.g. rash fever, pulse, lump)

Symptom

subjective evidence of disease only apparent to the patient (e.g. back pain or fatigue)

Incubation Period

period between exposure to infection and the appearance of the first signs and symptoms

Latency

time from infection to infectiousness (being able to pass the infection)

Infection

first step; occurs when infectious agents that may cause disease enter the body (invasion) and begin to multiply. transitions to disease when cells are damaged

Disease

characterized by signs and symptoms of an illness and tissue damage leading to pathological features/conditions

Infectivity

ability of an organism to establish an infection

Invasiveness

ability of an organism to spread to adjacent or distant tissues

Pathogenicity

ability to produce substances that damage tissues

Parasite Virulence

ability of a parasite to cause disease and tissue damage to host

Host Resistance

ability of an organism to limit growth, reproduction, or survival of invading parasite

Eosinophilia

increased production of eosinophils (a white blood cell) that is part of host defence against parasitic infections

Erythropoiesis

increased production of red blood cells due to anemia caused by parasite feeding

Neoplasia

uncontrolled proliferation of cells due to excessive parasite induced tissue damage and repair

Enterobius vermicularis

Pinworm

Trichuris trichiura

Whipworm

Ascaris lumbricoides

Giant Roundworm

Toxocara canis/cati

Dog/Cat Roundworm

Baylisascaris procyonis

Racoon Roundworm

Ancylostoma duodenale

Hookworm (Human)

Ancylostoma canium

Hookworm (Dog)

Necator americanus

Hookworm

Stronglyoides stercoralis

Threadworm

Trichinella spiralis

Pork Roundworm

Dirofilaria immitis

Heartworm

Loa Loa

Eye Worm

Wuchereria bancrofti

Causes Elephantiasis

Onchocerca volvulus

Causes River Blindness

Dracunculus medinensis

Firey Serpent/Guinea Worm