Parasites I and II

Question 1

name the top 4 parasitic infections

Answer 1

Question 2

describe physiology and reproduciton of protozoa

Answer 2

• 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)

Question 3

name the ciliates

Answer 3

move via cilia (protozoans)

• B. coli

Question 4

name the amoebas (sarcodina)

Answer 4

move via pseudopodias

• Acanthamoeba
• Naegleria fowleri
• E. histolytica

​ANoEba

Question 5

name the flagellates (mastigophora)

Answer 5

protozoa that move via flagella

• Giardia lambia
• Leishmania spp.
• Trichomonas vaginalis
• Trypanosoma cruzi
• Trypanosoma brucei

flaGeLlaTTTes

Question 6

name the sporozoa

Answer 6

spore forming protozoa

• Cryptosporidium
• Toxoplasma gondii
• Plasmodium spp.

Question 7

describe the physiology and reproduction of metazoa

Answer 7

• 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

Question 8

describe the breakdown of nematodes (round worms) into intestinal vs tissue nematodes

Answer 8

Question 9

name the 3 types of metazoa and the infective forms

Answer 9

Question 10

name clinical symptoms associated with helminthic infections

Answer 10

• 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

Question 11

explain the significance of polyparasitism

Answer 11

• 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

Question 12

describe nematodes

Answer 12

• 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

Question 13

name the intestinal nematodes

Answer 13

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

Question 14

name the tissue nematodes

Answer 14

• Toxocara
• Trichinella

Tissue = TT

Question 15

name the filarial nematodes

Answer 15

• Brugia malayi
• Onchocerca volvulus
• Wuchereria bancrofti

Fil(arial)-BOW wow

Question 16

describe symptoms associated wth nematode infections (e.g. Ascariasis)

Answer 16

• 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

Question 17

describe Ascaris (roundworm)

Answer 17

Question 18

Answer 18

Ascaris (roundworm)

Question 19

describe Enterobius (pinworm)

Answer 19

Question 20

Answer 20

Question 21

describe Trichuris (whipworm)

Answer 21

Question 22

Answer 22

Question 23

describe Ancylostom and Necator (hookworm)

Answer 23

Question 24

Answer 24

Question 25

describe Strongyloides

Answer 25

Question 26

Answer 26

Question 27

describe Toxocara

Answer 27

Question 28

Answer 28

Question 29

describe Trichinella

Answer 29

Question 30

Answer 30

Question 31

name the trematodes (flukes)

Answer 31

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

Question 32

describe the general features of trematodes (flukes)

Answer 32

Question 33

describe Fascioloposis buski

Answer 33

Question 34

Answer 34

Question 35

describe Paragonimus westermani

Answer 35

Question 36

Answer 36

Question 37

describe the general features of cestodes (tapeworms)

Answer 37

Question 38

name the cestodes

Answer 38

Helminths (metazoa) > platyhelminth (flatworm) > cestodes (tapeworms)

The worm has no digestive tract and are hermaphroditic

• Taenia saginata
• Taenia solium
• Echinococcus spp.

Question 39

describe the signs and symptoms of a tapeworm (cestode) infection

Answer 39

• 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