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Parasites need a host body and the haematophagous insect triatomine (descriptions "assassin bug", "cone-nose bug", and "kissing bug") is the major vector in accord with a mechanism of infection. The triatomine likes the nests of vertebrate animals for shelter, where it bites and sucks blood for food.
A perspective on the evolutionary options can be gained by considering four questions: the effect on the reproductive fitness of a parasite's hosts; the number of hosts they have per life stage; whether the host is prevented from reproducing; and whether the effect depends on intensity (number of parasites per host). From this analysis ...
During the initial weeks of infection, parasite replication is brought under control by the production of antibodies and activation of the host's inflammatory response, particularly cells that target intracellular pathogens such as NK cells and macrophages, driven by inflammation-signaling molecules like TNF-α and IFN-γ. [2]
One major axis of classification concerns invasiveness: an endoparasite lives inside the host's body; an ectoparasite lives outside, on the host's surface. Like predation, parasitism is a type of consumer–resource interaction , [ 3 ] but unlike predators , parasites, with the exception of parasitoids, are much smaller than their hosts, do not ...
When an intracellular parasite goes to enter a host cell, it is particular about the type of host cell. This is because most intracellular parasites are able to infect only a few different cell types. [21] Viruses use a number of host receptors to gain entry to the cell, usually by causing endocytosis. [7]
Inside the cells they undergo spontaneous transformation into oval-shaped amastigotes. [22] [23] Granulocytes selectively kill the promastigotes by oxidative mechanism, while amastigotes are resistant. [24] Then the surviving amastigotes undergo cell division using simple binary fission. Multiplication continues until the host cell can no ...
E. histolytica induces tissue damage by three main events: direct host cell death, inflammation, and parasite invasion. Once the trophozoites are excysted in the terminal ileum region, they colonize the large bowel, remaining on the surface of the mucus layer and feeding on bacteria and food particles.
Main article: Human parasite Endoparasites Protozoan organisms Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Source/Transmission (Reservoir/Vector) Granulomatous amoebic encephalitis and Acanthamoeba keratitis (eye infection) Acanthamoeba spp. eye, brain, skin culture worldwide contact lenses cleaned with contaminated tap water ...