CHAPTER 1 (HISTORY, INTRO) Flashcards
history, introduction, specimen collection
study of parasites, organisms that
live on and obtain their nutrients from another
organism, a field known as
parasitology
invasion in
the body
infection
invasion on the body
infestation
transport carriers known as
vectors
Even though treatment, prevention, and control
measures are available, parasitic infections still
occur and thus it is important to study
and monitor their trends, a field known as
epidemiology
Although they are distributed worldwide,
most parasitic infections are found in
underdeveloped tropical and subtropical countries
such as Haiti, Guatemala, and Myanmar
(Burma) and countries on the African continent
Populations at Risk for
Contracting Parasites
Individuals in underdeveloped areas and countries
Refugees
Immigrants
Visitors from foreign countries
Individuals who are immunocompromised
Individuals living in close quarters (e.g., prisons)
Children who attend day care centers
Modes of Parasite Transmission
Ingestion of contaminated food or drink (primarily water)
Hand-to-mouth transfer
Insect bite
Entry via drilling through the skin
Unprotected sexual relations
Mouth-to-mouth contact
Droplet contamination
Eye contact with infected swimming water
Parasite that is capable of existing independently of a host
Facultative parasite
Parasite that cannot survive outside of a host
Obligatory parasite
Parasite that is established inside of a host
Endoparasite
Parasite that is established in or on the exterior surface of a host
Ectoparasite
Host other than the normal one that is harboring a parasite
Accidental or incidental host
Host in which the adult sexual phase of parasite development occurs
Definitive host
Host in which the larval asexual phase of parasite development occurs
Intermediate host
Host harboring parasites that are parasitic for humans and from which humans may
become infected
Reservoir host
Host responsible for transferring a parasite from one location to another
Transport host
Parasite-harboring host that is not exhibiting any clinical symptoms but can infect
others
Carrier
Living together; the association of two living organisms, each of a different species
Symbiosis
Association of two different species of organisms that is beneficial to one and neutral to
the other
Commensalism
Association of two different species of organisms that is beneficial to both
Mutualism
Association of two different species of organisms that is beneficial to one at the other’s
expense
Parasitism
Relating to commensalism; the association between two different organisms in which
one benefits and has a neutral effect on the other
Commensal
Parasite that has demonstrated the ability to cause disease
Pathogenic
Which of the following people may be at risk for contracting a parasitic infection?
A. A toddler who attends an all-day preschool or day care center
B. A 25-year-old man who lives on his own in an apartment complex
C. A 37-year-old South American refugee
D. More than one of these: _______________
(specify)
A and C
Although parasitic life cycles range from simple to complex, they all have three common components
a mode of transmission,
a morphologic form that invades humans, known as
the infective stage,
and one (or more) forms that can be detected via laboratory retrieval methods, known as the diagnostic stage
Which of the following are key discoveries that contributed to current knowledge about parasites?
A. Consistent status quo preservation of samples
B. Techniques that indicate only the presence or absence of parasites
C. Modifications of traditional parasite identification techniques
D. Decrease in parasite incidence because of global travel
The information in this phase provides an understanding of the symptomatology and pathology of the parasite. Insights about the best the method of diagnosis and selection of appropriate antiparasitic medication may also be determined.
phase involves the route a parasite follows when in or on the human body
phase that provides crucial information
pertinent to epidemiology, prevention, and control.
[DIAGNOSTIC STAGE] the route a parasite follows independently of the human body
Which of the following key pieces of information may be extracted from the portion of a parasite’s life cycle that occurs outside the body? (Objective 1-11)
A. Parasitic disease symptoms and disease processes
B. Epidemiology and prevention and control measures
C. Appropriate parasite diagnosis methodologies
D. Selection of appropriate antiparasitic medication
B. Epidemiology and prevention and control
measures
A parasitic disease may affect the entire body or any of its parts. The major body areas associated with such processes include the following:
(1) the gastrointestinal (GI) and urogenital (UG) tracts;
(2) blood and tissue;
(3) liver, lung, and other major organs; and
(4) miscellaneous locations, such as cerebrospinal fluid (CSF), eye, skin, and extremities.
Which of the following groups of symptoms represents
those most commonly observed in parasitic
A. Diarrhea, abdominal cramping, and anemia
B. Enlargement of the spleen, fever, and chills
C. Skin lesions, abdominal pain, and diarrhea
D. Abdominal cramping, abdominal pain, and
diarrhea
Which of the following represent examples of available treatment therapies to combat parasitic infections?
A. Regulated exercise plan
B. Change in diet
C. Avoidance of vitamin supplements
D. More than one of these: ______________ (specify)
B. Change in diet
Symptoms Associated with
Parasitic Disease Processes
Diarrhea
Fever
Chills
Abdominal pain
Abdominal cramping
Elephantiasis
Anemia
Vitamin deficiency
Bowel obstruction
Edema
Enlargement of major organs
Skin lesions
Blindness
Parasite Treatment Options
Antiparasitic medications
Change in diet
Vitamin supplements
Fluid replacement
Blood transfusion
Bed rest
The problem of eradicating parasites is an ongoing process and is a key goal of international health groups such as the
World Health Organization (WHO) and Doctors Without Borders (Médecins Sans Frontières [MSF]).
Parasite Prevention and
Control Strategies
Development and implementation of parasite awareness
education programs
Use of insecticides and other chemicals
Use of protective clothing
Use of protective netting
Proper water treatment
Good personal hygiene
Proper sanitation practices
Proper handling, cooking, and protection of food
Avoidance of unprotected sexual relations
the most commonly
submitted sample for parasitic studies
Stool
Which of the following are examples of possible
parasite prevention and control measures?
(Objective 1-15)
A. Avoiding the use of insecticides
B. Practicing unprotected sex
C. Practicing proper sanitation practices
D. More than one of these: ________________
(specify)
C. Practicing proper sanitation practices
A process to remove fecal debris, which often resembles parasitic forms, is performed on a portion of sample after a preservative is added to it. Microscopic analysis of the resultant processed sample follows. This traditional parasite recovery method, often referred to as an
O&P, in which “O” stands for ova (eggs) and “P” stands for parasites
Other specimens, including _____ may also be examined for the presence of parasites
blood, tissue biopsies, CSF, sputum, urine, and genital material
is the procedure of choice for blood samples submitted for parasite study.
Giemsa stain followed by microscopic examination
a methodology for recovery of pinworm eggs
Cellophane tape preparation
for recovery of several parasites
Enterotest (string test)
Newer Parasite Laboratory Diagnosis Techniques
Direct fluorescent antibody (DFA)
Enzyme immunoassay (EIA)
Indirect fluorescent antibody (IFA)
Latex agglutination (LA)
Polymerase chain reaction (PCR)
Rapid immunochromatography technique
Suspicious forms that visually resemble parasites in terms of size and morphology are commonly encountered and are often referred to as
artifacts and/or confusers
polymorphonuclear leukocytes average 15 μm in size are artifacts or confusers of what parasite?
Entamoeba histolytica
Plant cells, as another example, resemble or acts as artifacts or confusers of what parasite?
Ascaris lumbricoides egg
artifacts and confusers also often referred to as
pseudoparasites
Which of the following specimen type is most often submitted for parasite study?
A. Blood
B. Sputum
C. Urine
D. Stool
D. Stool
Which of the following correctly represents the three major groups of clinically significant parasites?
A. Protozoa—worms; Metazoa—single-celled parasites; Arthropods—insects and their allies
B. Protozoa—insects and their allies; Metazoa—worms; Arthropods—single-celled parasites
C. Protozoa—single-celled parasites; Metazoa—worms; Arthropods—insects and their allies
D. Protozoa—single-celled parasites; Metazoa—insects and their allies; Arthropods—worms
D. Protozoa—single-celled parasites; Metazoa—insects and their allies; Arthropods—worms
