Parasites I and II Flashcards
name the top 4 parasitic infections
describe physiology and reproduciton of protozoa
- physiologically simple: assimilate organic nutrients
- acquired via pino or phagocytosis or enter via specialized site/structure
- respiration is usually facultatively anaerobic
- often have a survival form: cyst
- if no cyst: host-host transmission or vector necessary
- reproduction:
- binary fission (most)
- multiple fission with sexual reproduction (a few, e.g. Plasmodium spp)
name the ciliates
move via cilia (protozoans)
- B. coli
name the amoebas (sarcodina)
move via pseudopodias
- Acanthamoeba
- Naegleria fowleri
- E. histolytica
ANoEba
name the flagellates (mastigophora)
protozoa that move via flagella
- Giardia lambia
- Leishmania spp.
- Trichomonas vaginalis
- Trypanosoma cruzi
- Trypanosoma brucei
flaGeLlaTTTes
name the sporozoa
spore forming protozoa
- Cryptosporidium
- Toxoplasma gondii
- Plasmodium spp.
describe the physiology and reproduction of metazoa
- either:
- active ingestion of nutrients from host, or
- passive adsorption
- larger (cm to M) and multicellular
- free-living or parasitic
- no multiplication/replication of adult form in humans
- produce large number of eggs per day: >200,000
describe the breakdown of nematodes (round worms) into intestinal vs tissue nematodes
name the 3 types of metazoa and the infective forms
name clinical symptoms associated with helminthic infections
- usually a consequence of the worm’s:
- size
- movement
- longevity
- combined with long-term damage and ongoing immune stimulation
- presence of worms might result in:
- mechanical blockage
- pressure from the growing parasite
- nutritional deficiency
explain the significance of polyparasitism
- high #s of infections: increases chance of >1 parasite
- e.g. common roundworm (Ascaris lumbricoides)
- infects >25% of the human population: co-occurs with 47 other species of helminths or protozoa
- helminth co-infections can enhance morbidity for other infectious diseases, e.g. tuberculosis and HIV
describe nematodes
- the nematodes have cylindrical bodies and complete digestive tracts
- the body is covered with a cuticle, the oral opening may have hooks or suckers to attach to mucosal epithelium
- there are separate male and female sexes which mate and produce eggs within the human host
- the worms, larvae, or eggs may be diagnostic
name the intestinal nematodes
helminths (metazoa)
- Ascaris (round worm)
- Strongyloides
- Enterobius (pin worm)
- Ancylostoma and Necator (hook worm)
- Trichuris (whip worm)
intestinal problems = take A SEAT on the toilet
name the tissue nematodes
- Toxocara
- Trichinella
Tissue = TT
name the filarial nematodes
- Brugia malayi
- Onchocerca volvulus
- Wuchereria bancrofti
Fil(arial)-BOW wow
describe symptoms associated wth nematode infections (e.g. Ascariasis)
- mostly asymptomatic
- symptomatic infections vary with location & stage/form:
- lungs (larvae):
- asthma or pneumonia-like
- cough, shortness of breath, wheezing
- intestines (adult worms):
- diarrhea; or bloody stools
- general GI symptoms: nausea, vomiting, abdominal pain
- severe infxns: malnutrition, weight loss
describe Ascaris (roundworm)
Ascaris (roundworm)
describe Enterobius (pinworm)
describe Trichuris (whipworm)
describe Ancylostom and Necator (hookworm)
describe Strongyloides
describe Toxocara
describe Trichinella
name the trematodes (flukes)
Helminths (metazoa) > platyhelminths > trematodes (flukes)
while nematodes have complete digestive tracts, trematodes have a dead end digestive tract (intake and excretion same opening)
- Fasciolopsis buski
- Paragonimus westermani
- Fasiola hepatica
- Clonorchis sinensis
- Schistoma spp.
- S. japonicum, S mansoni, S. haematobium
describe the general features of trematodes (flukes)
describe Fascioloposis buski
describe Paragonimus westermani
describe the general features of cestodes (tapeworms)
name the cestodes
Helminths (metazoa) > platyhelminth (flatworm) > cestodes (tapeworms)
The worm has no digestive tract and are hermaphroditic
- Taenia saginata
- Taenia solium
- Echinococcus spp.
describe the signs and symptoms of a tapeworm (cestode) infection
- well adapted to host so usually minimal impact
- symptoms vary with:
- number of worms (burden)
- location (GI versus other body site)
- symptoms associated with GI infections include:
- abdominal discomfort
- diarrhea
- weight loss
- vit. B12 deficiency
