PARA LEC

• Parasitology is the area of biology concerned with the phenomenon of dependence of one living organism on another.
• Medical Parasitology is concerned with the animal parasites of humans and their medical significance, as well as their importance in human communities.
• Tropical Medicine is a branch of medicine which deals with tropical diseases and other special medical problems of tropical regions.
• A tropical disease is an illness, which is indigenous to or endemic in a tropical area.
• Many tropical diseases are parasitic diseases.
• Symbiosis is the living together of unlike organisms.
• Commensalism is a symbiotic relationship in which two species live together and one species benefits from the relationship without harming or benefiting the other.
• Mutualism is a symbiosis in which two organisms mutually benefit from each other.
• Parasitism is a symbiotic relationship where one organism, the parasite lives in or on another for its survival and usually at the expense of the host.
• Parasite is an organism which lives in or on the body of another organism for growth and survival.
• Host is a plant or an animal that harbors the parasite and is usually larger than the parasite.
• Ectoparasite is an organism which lives on the outside of the host (infestation).
• Endoparasite is an organism which lives within the body of the host (infection).
• Oviparous parasites lay immature/ unembryonated eggs (Ex: Helminths, Enterobius vermicularis).
• Ovoviviparous parasites lay mature eggs (Ex: Stronglyloides stercoralis).
• Larviparous parasites lay larva (Ex: Trichinella spiralis).
• Examples of diseases transmitted by American cockroaches include reduviid bug and tse-tse flies.
• Animal-borne diseases are those where the parasite is transmitted from an animal to a human, also known as zooanthroponosis, such as Enterobius vermicularis.
• Portals of entry into the body can include the mouth (oral cavity), skin, and others, such as sexual contact, transplacental transmission, and transmammary transmission.
• Airborne diseases are those that can be transmitted through the air, such as Ascaris lumbricoides and Enterobius vermicularis.
• Autoinfection is when an individual infects themselves, such as in the case of Trichomonas tenax and Entamoeba gingivalis.
• Examples of diseases transmitted by mosquitoes include malaria, filariasis, leishmaniasis, and sandfly fever.
• Contact transmission is when the parasite is very infective and does not need to go through further development, such as in the case of Trichomonas vaginalis and Enterobius vermicularis.
• Other portals of entry can include sexual contact (Trichomonas vaginalis), transplacental transmission (Toxoplasma gondii), and transmammary transmission (Strongyloides stercoralis).
• Examples of diseases that can be transmitted through the mouth (oral cavity) include ingestion of embryonated eggs (Ascaris lumbricoides) and cysts (Entamoeba histolytica), and intimate oral contact with Trichomonas tenax and Entamoeba gingivalis.
• Portals of entry through the skin can involve active penetration by filariform larvae (Hookworm) and cercariae (Schistosomes).
• Portals of exit can include stool (recovery of ova) and urine (T. vaginalis).
• Viviparous parasites have young developed inside the body of the parent.
• A human being, when infected by a parasite may serve as its only host, its principal host with other animals also infected, or its incidental host with one or other animals as principal host.
• Cestodes have an adult form and a larva (cysticercoid) form, which is usually the infective stage.
• Diphyllobothrium latum, also known as sparganum, is a species of parasitic worm that can be found in the rectal biopsy sample.
• Haematobium is a species of parasitic worm that causes infection in the human urinary tract.
• Monoecious parasites have both male and female reproductive organs found in one parasite (Ex: Cestodes).
• Trichinella spiralis is a species of parasitic worm that can be found in muscle tissue.
• Taenia solium, also known as cysticercus cellulosae, is a species of parasitic worm that can be found in the rectal biopsy sample.
• Prevalence is the number (usually expressed in percentage) of individuals in a population estimated to be infected with a particular parasite species at a given time.
• Epidemiology is the study of patterns, distribution, and occurrence of disease.
• The transmission of parasites involves three factors: source of infection, mode of transmission, and presence of susceptible host.
• Hookworms and Strongyloides have a rhabditiform larva form that is free-living and feeding, and a filariform larva form that is usually the infective stage.
• Protozoans have a trophozoite form, which is the vegetative, motile, and feeding form, and a cyst form, which is the resistant form and usually the infective stage.