Test 4: Intro Parasitology Flashcards
What are the six major divisions Parasites are classified into?
- Protozoa
- Nematoda (Roundworm)
- Platyhelminthes (Flatworms)
- Pentastomids (Tongue Worm)
- Acanthocephala (Thorny-headed worms)
- Arthropoda
What other parasite are included in the Platyhelminthes division?
- Cestoda (tapeworms)
- Trematoda (Flukes)
Define: Symbiosis
Two organisms of different species living together
Define: Commensalism
Symbiotic relationship in which the parasite is benefited and host is neither benefited nor harmed
Define: Mutualism
Symbiotic relationship in which both parasite and host are benefited
What is defined by: Symbiotic relationship in which one organism, the parasite, is metabolically dependent on another organism, the host; the host may or may not be harmed in the relationship?
Parasitism
Define: Pathogenic Parasite
Parasite that harms the host
Define: Facultative Parasite
Normally free living organism but may become an opportunistic parasite
Define: Obilgatory Parasite
Cannot survive in a free living state
Define: Endopatasite:
A parasite living inside the host
Define: Ectoparasite
A parasite living on the external surface of the host
What is defined by: Any living organism, animal or plant that harbors or nourishes another organism.
Host
What is defined by: The host that harbors the adult or sexually reproducing stages of a parasite.
Definitive Host
What is defined by: That host which harbors the immature, larval, or asexually reproducing forms of a parasite.
Intermediate Host
What is defined by: A host which replaces man in the life cycle of the parasite.
Reservoir Host
What is defined by: A host that serves as a transport host in which the parasitic forms undergo no development, but passes on to the final host.
Paratenic Host
Define: Life Cycle
Process of a parasite’s growth, development and reproduction, which proceeds in one or more different host depending on the species of parasites
Define: Infective Stage
A stage when a parasite can invade a human body and live in it
Define: Infective Route
The entrance which the parasite invades the human body
Define: Infective Mode
How the parasite invades the human body
What is defined by: A Carrier, usually an arthropod, which transmits an infective form of the parasite from host to another?
Vector
What is defined by: A reinfection in which the host is its own source of infection from a source already present in the body?
Autoinfection
What route of infection pertains to taking in orally in food, water, or aerosols, etc.., remain in GI tract, Internal migration to other organs, Migration through other host systems and return to GI sites?
Ingestion
This route of infection is through host tissues, skin or mucous membranes, and remains on or within epidermis or subcutaneous tissues, and/or penetrates to other host organs or tissues?
Active Penetration
This route of infection occurs through host tissues by vector or agent from Arthropod-borne mouth parts, salivary glands, waste products or via transfusion in which contaminated?
Injection
This route of infection occurs via transmission of parasites across the placental barrier from mother to fetus?
Congenital
Ingestion of what type of medicinal substances prior to collection may interfere w/examination of specimen?
- Antacids
- Antidiarrheals
- Mineral oil
- Antibiotics
Administration of barium sulfate will make stool specimens difficult to examine for how long after?
1-2 weeks
What is the container of choice for fecal specimen collection?
Cardboard w/wax coating and tight-fitting lid (prevents leakage/loss of moisture)
Why is it important to collect feces directly into the container and to avoid contamination in the toilet?
- Water: destroy trophozoites
- Water: may contain free-living organisms
- Urine: adverse effect on motility of trophozoites
What is the best procedure/process for protozoan detection in fecal specimen?
- Collection of at least three specimens
- 6-10 day intervals
What is one of the most important factors affecting diagnosis of infection when using a stool sample?
Age of stool specimen
What is the suggested time frame for examination of liquid and diarrheic specimens?
Within 30 min of passage
type of specimen where trophozoites may be found
What is the suggested time frame for examination of soft specimens of stool?
Within one hour of passage
What is the suggested time frame for examination of formed specimens of stool?
- Delayed several hours or longer
- Should be same day
What are some of the fecal preservatives used in specimen collection?
- 10% Formalin
- Polyvinyl Alcohol (PVA)
- Merthiolate-Iodine-Formalin (MIF)
- Sodium Acetate Formalin (SAF)
- Store at 4C but not frozen
What test can be used to recovery and exam pinworm eggs (Enterobius Vermicularis), best before defecation, bathing, or dressing in the morning?
Scotch Tape Prep (Pinworm Prep)
What test can be used to detect parasites, protozoa, and helminths in the upper part of the small intestine?
Enterotest (String Test)
What is the process for the Enterotest?
1) NPO 12hrs prior
2) End of string tape to cheek or neck
3) Swallow capsule
4) Capsule dissolves and remainder of string unravels
5) Pt relaxes 4 hrs
6) Material gathers on string
7) String pulled out and placed in container
8) Remove mucous from string and examine via wet mount technique
Nucleic Acid Testing provides high sensitivity and specificity and the Enteric parasite panels of the BD Max 3 and Luminex 200 tests for what?
Giardia
Cryptosporidium
Entamoeba
Name some of the other types of clinical specimens?
- Blood
- Sputum
- Urethral and Vaginal Exudates
- Urine Sediment
- CSF
- Skin Scrapings
- Biopsy
- Serum
- Bone Marrow
What are the steps of control of parasitic infections?
1) Surveillance
2) Interruption of life cycle
3) Protection
4) Therapeutic measures
5) Hand Washing
6) Education of exposed population
What is involved in the surveillance step of control of parasitic infections?
Monitoring of
- Incidence
- Prevalence
- Distribution of disease
- Severity of disease
What is the best method of interruption of the parasitic life cycle?
Proper disposal of human and animal waste
What methods can be used in the purification of drinking water in the interruption of parasitic life cycle step?
- Treat w/ chlorine or iodine
- Prevent contamination of ground water
- Replace filtration systems
In the processing and treatment of food supply what temp and or freezing protocols allow for interruption of parasitic life cycle?
- Cooking/heating: 1hr at 55C
- Freezing: 20 days at -10C
What is another method used to Interrupt the parasitic life cycle?
Elimination of intermediate host(s) or vectors
What is involved in the Protection step of Control of parasitic infections?
- Prophylaxis: entering endemic areas
- Immunization
What does the Therapeutic Measures step of Control of parasitic infections involve?
- Isolation of infected
- Curative therapy: Antiparasitic drugs
- Antimalarial: Chloroquine Phosphate (Aralen
- Antihelminthic: Praziquantel (Biltricide)
- Antiprotozoal: Metronidazole (Flagyl)
What are the different forms the parasites might have for study?
- Adult form
- Larval form
- Egg/Ova form
- Trophozoite Form
- Cysts Form
