Lecture 11 - Parasitology Flashcards
What are the 3 ways that a parasite exists with their host?
Symbiotic, Commensalism, Infectious
Types of Enteric Protozoa
Giardia intestinalis Entamoeba histolytica Dientamoeba fragilis Crytosporidium parvum & hominis Cyclospora cayetanesis
How do we typically obtain enteric protozoa?
From contaminated food
What is the difference between a cyst form and a trophozoite form?
Cysts are the infective form while trophozoites are the active form
How is E. Protozoa diagnosed?
From examination of the stool
Are E. Protozoa pathogenic/infectious?
YES! However, we don’t usally have symptoms/get sick.
What is the transmission of E. Protozoa most commonly associated with?
Foreign travel and campling
What is unique about they symptoms of E. Protozoa
They are usually prolonged or recurrent
Where does G. Intestinalis infect?
The duodenum
Why is G. Intestinalis so common?
Found in water supply and is resistant to chlorination in the treatment. Must use iodine or UV light to kill
What size is G. Intestinalis
SOOOO SMALL. Need 5 stool samples to rule out infection
What are a few symptoms of G. Intestinalis
Soft stool, weight loss and the possibility of becoming lactose intolerance
What is the most common symptom of Entamoeba histolytica?
Blood stool & diarrhea
How is E. Histolytica diagnosed?
Through a blood test
What is a unique feature about Dientamoeba fragilis that no other enteric protozoa exhibit?
Does not have a cyst form
What is D. Fragilis transmitted by?
Through pinworm eggs (child worms)
What is unique about D. Fragilis’ nuclei?
TWO NUCLEI! Also in a cross section to form into 4 sections
How infectious is Cryptosporidium parvum/hominis
Extremely! Only need a little to cause massive infection
Where is cryptosporidium parvum/hominis most commonly found
Public pools, spas, splash pads etc
How is crypto diagnosed?
Using acid fast staining
What is the most common form of transmission for cyclospora cayetanensis
Imported fruit transmission
How is cyclospora diagnosed?
Acid fast stains
What are the types of Blood & Tissue Parasites?
Plasmodium Toxoplasma gondii Leishmania Trypanosoma Free living ameboe
What is the more common name for plasmodium?
Malaria
How is plasmodium transmitted?
Through mosqitos
Why is plasmodium so lethal?
Bacterium gets into liver within 30 minutes
Why is there no malaria vaccine?
Bacterium moves too quickly, gets to the liver before vaccine can act
What causes fever in malaria?
The release of merozoites
What is the most common symptom of plasmodium falciparum?
Constant fever
How does plasmodium falciparum kill?
It eats away at the bone marrow and kills RBCs
What is the most common symptom of plasmodium vivax?
Fever every 49 hours
What does plasmodium vivax attack?
Young RBC
What is the most common symptom of toxoplasma gondii?
Mostly asymptomatic unless immunocompromised
What are the 4 forms of leishmaniasis?
Cutaneous, mucocutaneous, visceral, and sand fly inoculating a promastigotes
What is the main symptom of leishamaniasis?
Huge malformations all over the body
How is leishmaniasis diagnoised?
Biopsy or PCR
What are the two forms of trypanosomiasis and where in the world are they most commonly found?
Cruzi - south america
Brucei - africa
How is Chagas disease transmitted?
By the kissing bug!
How does the kissing bug infect?
Comes out at night from living in ur crib and bites your eye filling up on blood. Becomes so large that it shits on you and then you rub the poopy in ur eye and get infection
What is unique about african sleeping sickness transmission?
Bug is attracted to humans by sight, not chemicals. aka, repellent doesn’t work
