General Introduction to Parasitology Flashcards
Sastry A.s., & Bhat, S. (2019). Essentials of Medical Parasitology (2nd ed.). Jaypee Brothers Medical Pub.
Amplifier host
It is the host, in which the
parasite lives and multiplies exponentially.
What is the purpose of binomial nomenclature in parasitology?
Binomial nomenclature is a system of naming organisms using two names, a genus name and a species name. This system was developed by Carl Linnaeus in the 18th century and is still used today. The purpose of binomial nomenclature is to provide a unique and standardized way to identify and classify organisms.
What are the sources of the names used in binomial nomenclature for parasites?
The names used in binomial nomenclature for parasites can be derived from a variety of sources, including the names of their discoverers, Greek or Latin words related to the geographical area where they are found, the habitat of the parasite, the hosts in which they are found, or their size and shape.
What are the taxonomic units used to classify parasites?
Parasites are classified using a hierarchical system of taxonomic units, including the kingdom, subkingdom, phylum, subphylum, superclass, class, subclass, order, suborder, superfamily, family, genus, and species.
How are the generic and species names of parasites written?
The generic name of a parasite always begins with an initial capital letter, while the species name begins with an initial small letter. For example, the scientific name of the parasite that causes amoebic dysentery is Entamoeba histolytica.
What is a parasite?
A parasite is a living organism that lives in or upon another organism (host) and derives nutrients directly from it, without giving any benefit to the host.
How can parasites be classified based on their location in the host?
Parasites can be classified as ectoparasites or endoparasites. Ectoparasites inhabit the surface of the body of the host without penetrating into the tissues, while endoparasites live within the body of the host.
What are the two main groups of parasites studied in Medical Parasitology?
Protozoa and helminths (animal parasites).
What is the difference between an obligate parasite and a facultative parasite?
An obligate parasite (Protozoa) cannot exist without a parasitic life in the host, while a facultative ( Acanthamoeba ) parasite can live a parasitic life or a free-living life, when the opportunity arises.
What is an accidental parasite?
An accidental parasite is a parasite that infects an unusual host.
What is an aberrant parasite or wandering parasite?
An aberrant parasite or wandering parasite is a parasite that infects a host where it cannot live or develop further.
What is the difference between a definitive host and an intermediate host?
A definitive host is a host in which the adult parasites replicate sexually, while an intermediate host is a host in which the parasite undergoes asexual multiplication.
What is a reservoir host?
A reservoir host is a host that harbors the parasite and serves as an important source of infection to other susceptible hosts.
What is a paratenic host?
A paratenic host is a host in which the parasite lives but cannot develop further and is not essential for its life cycle.
What is an amplifier host?
An amplifier host is a host in which the parasite lives and multiplies exponentially.
Can a parasite have more than one definitive host?
Yes, a parasite can have more than one definitive host. For example, the malaria parasite can have multiple definitive hosts, including different species of mosquitoes.
Can a parasite have more than one intermediate host?
Yes, a parasite can have more than one intermediate host. For example, the liver fluke Fasciola hepatica has two intermediate hosts: a snail and a sheep.
A patient presents with a history of abdominal pain, diarrhea, and weight loss. The patient reports consuming raw vegetables from a local farm. What is the most likely mode of transmission for the patient’s infection?
Oral or feco-oral route
Explanation: The patient’s consumption of raw vegetables contaminated with feces containing the infective stages of a parasite is the most likely mode of transmission. This is a common route of transmission for many parasitic infections, including those caused by protozoa (e.g., Entamoeba histolytica) and helminths (e.g., Ascaris lumbricoides).
A patient presents with a history of skin irritation and itching on the soles of their feet. The patient reports walking barefoot over fecally contaminated soil. What is the most likely mode of transmission for the patient’s infection?
Penetration of the skin and mucous membranes
Explanation: The patient’s history of walking barefoot over fecally contaminated soil suggests that the infection was transmitted through the penetration of the larval forms of a parasite through unbroken skin. This is a common mode of transmission for certain helminths, such as Strongyloides stercoralis and hookworms.
A patient presents with a history of fever, chills, and muscle aches. The patient reports being bitten by a mosquito while traveling in a malaria-endemic region. What is the most likely mode of transmission for the patient’s infection?
Bite of vectors
Explanation: The patient’s history of being bitten by a mosquito in a malaria-endemic region suggests that the infection was transmitted through the bite of an infected mosquito. This is the primary mode of transmission for malaria, which is caused by the protozoan parasite Plasmodium species.
A patient presents with a history of congenital heart defects and developmental delays. The patient’s mother reports having a history of toxoplasmosis during pregnancy. What is the most likely mode of transmission for the patient’s infection?
Vertical transmission
Explanation: The patient’s history of congenital heart defects and developmental delays, combined with the mother’s history of toxoplasmosis during pregnancy, suggests that the infection was transmitted from the mother to the fetus during pregnancy. This is known as vertical transmission and can occur with certain parasitic infections, including toxoplasmosis.
A patient presents with a history of recurrent intestinal infections with the same parasite. The patient reports poor hygiene and a habit of biting their nails. What is the most likely mode of transmission for the patient’s infection?
Autoinfection
The patient’s history of poor hygiene and nail biting suggests that the infection is being transmitted to the same person by contaminated hand (external autoinfection). This is a common mode of transmission for certain intestinal parasites, such as Cryptosporidium parvum, Taenia solium, Enterobius vermicularis, Strongyloides stercoralis, and Hymenolepis nana.
A patient presents with a history of vaginal itching and irritation. The patient reports having unprotected sex with a new partner. What is the most likely mode of transmission for the patient’s infection?
Sexual contact
The patient’s history of unprotected sex with a new partner suggests that the infection was transmitted through sexual contact. This is a common mode of transmission for certain parasites, such as Trichomonas vaginalis. However, other parasites, such as Entamoeba, Giardia, and Enterobius, can also be transmitted rarely by sexual contact among homosexuals.
A patient presents with a history of fever, chills, and muscle aches. The patient reports receiving a blood transfusion several weeks prior to the onset of symptoms. What is the most likely mode of transmission for the patient’s infection?
Blood transfusion
Explanation: The patient’s history of receiving a blood transfusion several weeks prior to the onset of symptoms suggests that the infection was transmitted through the transfusion of blood or blood products. This is a potential mode of transmission for certain parasites, such as Plasmodium species (malaria), Babesia species (babesiosis), Toxoplasma species (toxoplasmosis), Leishmania species (leishmaniasis), and Trypanosoma species (African sleeping sickness and Chagas disease).
