Introduction to Parasitology Flashcards
Organisms that live on and obtain their nutrients from another organism.
Parasite
Organisms that harbor and provide sustenance for another organism.
Host
Organisms that are beneficial to one and neutral to one another.
Commensal
The parasite that has demonstrated the ability to cause disease.
Pathogenic
What are the common components of parasitic life cycles?
- Mode of transmission
- Infective stage
- Diagnostic stage
A morphologic form that invades humans.
Infective stage
One or more forms that can be detected via laboratory retrieval method.
Diagnostic stage
The majority of infections of cestodes, trematodes, and intestinal protozoans.
Foodborne
- Taenia solium
- Taenia saginata
- Diphyllobothrium latum
Larval stage —> Food
- Entamoeba histolytica
- Giardia lamblia
Cysts —> Water
- Clonorchis
- Opisthorchis
- Haplorchis spp
Larval stage —> Freshwater fish
What are the two modes of transmission in skin penetration?
- Exposure to soil
- Exposure to water
- Hookworm
- Strongyloides spp
Exposure to soil
- Schistosoma spp
Exposure to water
It can cross the placental barrier during pregnancy.
Congenital
Example of the mode of transmission in Congenital
Toxoplasma gondii
- Ancylostoma
- Strongoloides spp
Transmammary
- Ascaris lumbrocoides
- Enterobius vermicularis
Inhalation
- Trichomonas vaginalis
Sexual intercourse
Lack of sanitary toilets and the use of night soil or human excreta as fertilizer
Soil
List of Soil-Transmitted Helminths (STH)
- Hookworms
- Ascaris lumbrocoides
- Trichuris trichiura
- Strongyloides stercoralis
May be contaminated with a cyst of amebae or flagellates, as well as cercariae of?
Schistosoma spp
As exemplified by a number of trematode and cestode infections.
Food
Intestinal and liver fluke infections
Freshwater fish
Paragonimiasis
Crabs
Artyfechnostomum malayanum
Bullastra snails
Include another person, his beddings and clothing, as well as the immediate environment he has contaminated, or even one’s self.
Contact transmitted
The infected person himself is the source of the infection
Autoinfection
Wild or domesticated, may also harbor parasites
Other animals
Cats’ sources of infection?
Toxoplasma
Rat’s sources of infection?
Hymenelopis nana
Give one example of parasite prevention and control strategies.
- Use of protective clothing
- Good personal hygiene
In how many specimens is recommended to examine within a 10-day span?
3 specimens
In how many minutes does the liquid specimen pass or be placed in preservative?
30 minutes
In how many minutes does the soft specimen pass or be placed in preservative?
60 minutes | 1 hour
In how many hours when formed stools place an aliquot in preservative and refrigerate the remainder?
24 hours
Stool samples should collected a week after the intake of any of these drugs.
Intake of drugs / Medicines
Give examples of intake drugs or medicines.
- Antacids
- Anti-diarrheal
- Barium
- Bismuth
- Laxatives
It decreases the number of protozoans for several weeks.
Intake of antibiotics
Formed stool
Thum-sized (2-5 grams)Wa
Watery stool
5-6 tablespoons
In how many minutes does trophozoite will die after passage?
30-60 minutes
Does it ensure that parasites are present in the identifiable stage?
Preservation
What degrees Celsius is acceptable in the temporary storage of fecal samples?
3-5 degrees Celsius
In how many days that intestinal protozoa may be undetectable?
5-10 days
In how many weeks does tetracycline modify intestinal flora and may prevent recovery after drug cessation?
2 weeks
Early morning specimen is best and it is most commonly concentrated.
Sputum
Early morning or 1st void
Urine
Saline wet swabs
Genitalia
Concentration procedures as well as preservatives: good for eggs larvae and amoebic cysts
Merthiolate-iodine-formalin (MIF)
It is best for amoebic trophozoites: can prepare permanent stain slides from specimens preserved this way.
Polyvinyl Alcohol (PVA)
Good for amoebic trophozoites environmentally safer than PVA.
Sodium Acetate-Acetic Acid-Formalin
It is used for fresh stool samples good for trophs and cysts.
Schaudinn’s Fluid
What are the two types of concentration techniques?
- Formalin-Ethyl Acetate Sedimentation
- Zinc Sulfate Flotation Techniques
What are the advantages of Formalin-Ethyl Acetate Sedimentation?
Can stay in formalin
What are the disadvantages of Formalin-Ethyl Acetate Sedimentation?
More debris
What are the advantages of Zinc Sulfate Flotation Techniques?
Not flammable
What are the disadvantages of Zinc Sulfate Flotation Techniques?
Large eggs and operculated eggs are often missed
Color of Blood | Iron
Black
Color of barium or absence of bile
Light tan or White
Easy to perform and most commonly used
Trichrome stain
Use for blood smears
Giemsa stain and Wright stain
Use to diagnose Cryptosporidium, Isopora, and Cyclospora
Acid Fast Stain
Use to diagnose Microsporidiosis
Modified trichrome stain
It can enhance detection of microfilarial sheath.
Iron Hematoxylin Stain
Detects motility must use low lights
Saline
It kills trophozoites; enhances nuclear material
Iodine
