PARASITOLOGY

• Symbiosis is the living together of unlike organisms.
• Commensalism is a situation where two species live together, one benefits from the relationship without harming or benefiting the other.
• Entamoeba coli is an example of a commensalism.
• Mutualism is a situation where two organisms benefit from each other.
• Termites and the flagellates inside their digestive system are examples of mutualism.
• Parasitism is a situation where one organism lives in or on another for its survival at the expense of the host.
• Entamoeba histolytica is an example of a parasitism.
• Endoparasite is a parasite that lives inside the body of the host.
• Ectoparasite is a parasite that lives outside the body of the host.
• Erratic parasite is a parasite found in an organ where it is not its usual habitat.
• Obligate parasite is a parasite that needs a host to complete their development.
• Facultative parasite is a parasite that may exist in a free-living state and may become parasitic when the need arises.
• Accidental/incidental parasite is a parasite that established itself in a host where it does not ordinarily live.
• Permanent parasite is a parasite that remains on or in the body of the host for its entire life.
• The larval stage of Trichinella spiralis is filariform, with a sheath that is (–), a tail that is notched, and a muscle larva that is not encysted.
• Temporary parasite is a parasite that lives on the host only for a short period of time.
• The adult male of Trichinella spiralis has conical papillae, while the female has club-shaped uterus (viviparous/larviparous).
• Trichinella spiralis propagates through the ingestion of meat.
• Freezing destroys the larva of Trichinella spiralis.
• The adult female of Strongyloides stercoralis is capable of parthenogenesis, meaning it can reproduce without the benefit of a male.
• Strongyloides stercoralis is a facultative nematode that parasitizes in the small intestine and is free-living in soil.
• Trichinella spiralis requires two hosts to complete its life cycle and is propagated by black and brown rats.
• The symptoms of Trichinella spiralis infection include muscle edema, muscle pain, difficulty in breathing and swallowing in the larval stage, and abdominal pain, diarrhea in the adult stage.
• The larval stage of Strongyloides stercoralis is rhabditiform, with a short buccal cavity and a prominent or conspicuous genital primordium.
• Diagnosis of Trichinella spiralis infection can be done through muscle biopsy, immuno-tests, and xenodiagnostic tests.
• Baermann funnel technique is used for the detection of Strongyloides stercoralis.
• Humans can be both dead-end and intermediate hosts for Trichinella spiralis.
• Spurious parasite is a free-living organism that passes through the digestive tract without infecting the host.
• Dirofilaria immitis is a parasite that infects humans and causes solitary, peripheral nodules in the lung (coin lesions), or as subcutaneous nodule.
• Onchocerca volvulus is a parasite that inhabits subcutaneous tissue and is vectored by Simulium (black fly).
• Trematodes are a phylum of flat, leaf-like, hermaphrodite, egg-operculated, and metacercaria-infecting parasites.
• Anisakis causes Herring’s disease and is vectored by ingestion of raw fish (sashimi).
• Dracunculus medinensis is the longest nematode of man and is vectored by ingestion of crustaceans.
• Angiostrongylus cantonensis causes human eosinophilic meningoencephalitis and is vectored by ingestion of mollusks and rats.
• Loa loa is a parasite that inhabits subcutaneous tissue and is vectored by Chrysops and Tabanid (mango fly).
• Knott’s technique involves isolation of microfilaria using blood, formalin, and Giemsa stain.
• Schistosomes are a phylum of elongated and cylindrical, separate sexes, egg-non-operculated, and skin penetration-infecting parasites.
• Brugia malayi is a parasite that inhabits lymphatics and is vectored by Mansonia.
• Wuchereria bancrofti is a parasite that inhabits lymphatics and is vectored by Aedes and Anopheles.
• Dipetaloma perstans (Acanthoculonema perstans) is a parasite that inhabits body cavities and is vectored by Culicoides.