Introduction to Parasitology Flashcards
General Considerations | Belizario 2013
the area of biology concerned with the phenomenon of dependence of one living organism on another
parasitology
concerned primarily with parasites of humans and their medical significance, as well as their importance in human communities
Medical Parasitology
a branch of medicine that deals
with tropical diseases and other special medical problems of tropical regions
Tropical
Medicine
an illness, which is indigenous to or endemic in a tropical area but may also occur in sporadic or epidemic proportions in areas that are not tropical.
tropical disease
Many tropical diseases are ______
parasitic
diseases
living together of unlike organisms. It may also involve protection or other advantages to one or both organisms
Symbiosis
What are different forms of symbiosis?
Commensalism
Mutualism
Parasitism
a symbiotic relationship in which two species live together and one species benefits from the relationship without harming or benefiting the other
Commensalism
a symbiosis in which two organisms mutually benefit from each other like termites and the flagellates in their digestive system, which synthesize cellulase to aid in the breakdown of ingested wood.
Mutualism
a symbiotic relationship where one organism, the parasite, lives in or on another, depending on the latter for its survival and usually at the expense of the host.
Parasitism
often described according to their habitat or mode of development
Parasites
A parasite living inside the body of a host is known as an _____
endoparasite
a parasite living outside the body of a host is an ______
ectoparasite
The presence of an endoparasite in a host is called an _________
infection
The the presence of an ectoparasite on a host is called an _____
infestation
A parasite is considered _____ when it is found in an organ which is not its usual habitat
erratic
Most parasites are _____ _____ in that they need a host at some stage of their life cycle to complete their development and to propagate their species.
obligate parasites
Obligate parasites such as _____ depend entirely upon their host for existence.
tapeworms
A ____ _____ may exist in a free-living
state or may become parasitic when the need arises
facultative parasite
A parasite, which establishes itself in a host where it does not ordinarily live, is called an ______ or ______ parasite.
accidental or incidental
A _____ parasite remains on or in the body of the host for its entire life
permanent
a ______ parasite lives on the host only for a short period of time
temporary
A _____ parasite is a free-living organism that passes through the digestive tract without infecting the host.
spurious
____ can be classified into various types based on their role in the life cycle of the parasite.
Hosts
one in which the parasite attains sexual maturity
definitive or final host
In ______, for example, humans are considered the definitive host.
taeniasis
An ____ host harbors the asexual or larval stage of the parasite.
intermediate
Pigs or cattle serve as intermediate hosts of ________ ___while snails are hosts of ________ ___
Taenia spp.,
Schistosoma spp.
If there is more than one intermediate host, these can be classified as ______ and _____ intermediate hosts
first and second
A _____ host is one in which the parasite does not develop further to later stages. However, the parasite remains alive and is able to infect another susceptible host.
paratenic
There are also other animals that harbor the parasite other than definitive, intermediate, and paratenic hosts. These are known as _____ hosts.
reservoir
They allow the parasite’s life cycle to continue and become additional sources of human infection.
reservoir hosts
T or F: Humans are not always the final host.
T
Humans may be the most important host in the spread of the disease or an ________ of parasites prevalent in other animals
incidental host
are responsible for transmitting the parasite from one host to another
Vectors
A _____ ______ transmits the parasite only after the latter has completed its development within the host. It is is therefore an essential part of the parasite’s life cycle
biologic vector
A __________ or ________ _______only transports the parasite.
mechanical or phoretic vector,
Majority of parasites are ____ which are harmful and which frequently cause mechanical injury to their hosts
pathogens
A ____ harbors a particular pathogen without manifesting any signs and symptoms
carrier
the process of inoculating an infective agent
Exposure
connotes the establishment of
the infective agent in the host
infection
the period between
infection and evidence of symptoms
incubation period
The incubation period is
sometimes referred to as the ____
clinical incubation period
the period between infection or acquisition of the parasite and evidence or demonstration of infection
pre-patent period or biologic incubation period
results when an infected individual becomes his own direct source of infection
Autoinfection
happens when the already infected individual is further infected with the same species leading to massive infection with the parasite
Superinfection or hyperinfection
There are various sources of parasitic
infections. The most common sources are _____ ___ and ___
contaminated soil and water.
Lack of sanitary toilets and the use of night soil or human excreta as fertilizer allow the eggs to come in contact with the soil and favor the development of?
Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, and hookworm
_____may be contaminated with cysts of amebae or flagellates, as well as cercariae of Schistosoma
Water
Another possible source of infection is _____, which may contain the infective stage of the parasite, as exemplified by a number of trematode and cestode infections.
food
Raw crabs are considered a delicacy
in areas where ____ is endemic,
paragonimiasis
raw Bullastra snails are associated with
________ __________infection.
Artyfechinostomum malayanum
___ can also transmit infection.
Mosquitoes are vectors of malaria and filarial parasites.
Arthropods
Triatoma bugs are carriers of
_______ ________causing Chagas disease
Trypanosoma cruzi
Cats are direct sources of
_____ infection, while rats may be infected
with _______ _____
Toxoplasma
Hymenolepis nana
Autoinfection where the infected
person himself is the source of infection is seen in the life cycles of (3)
Capillaria philippinensis,
Enterobius vermicularis,
Hymenolepis nana, and
Strongyloides stercoralis
