Parasitology

Question 1

What are the two types of parasites?

Answer 1

Parasites

• Protozoa
  
  • Amoeba
  • Sporozoa
  • Flagellates
  • Ciliates
• Metazoa
  
  • Flatworms
    
    • Trematodes
    • Cestodes
  • Roundworms

Question 2

Characteristics of parasitic disease?

Answer 2

Characterisitics of parasitic disease

• Symptoms are usually proportional to parasite burden
• The more you have, the worse you get
• Eosinophilia may suggest a parasitic infection

Question 3

What is the most common transmission?

Answer 3

Transmission of parasitic disease

• Food/waterborne (fecal/oral) - most common
• Contact
• Droplets
• Airborn
• Zoonotic
• Verticle

Question 4

Ecoparasites

• Bedbugs
• Fleas
• Lice
• Scabies

Answer 4

Ectoparasites - live on the body, clothing, and beds

• Bedbugs
  
  • Looks like a mosquito or flea bite
  • Ask pt if they travel a lot e.g. hotel rooms
  • Treatment is the source / home
  • No real tx for the body
• Fleas
  
  • Underserved areas
  • Outside in yeard
  • Common when people keep pets outside
  • Tx the source - Dawn soap in the yard
• Lice
  
  • Underserved areas, homelessness
  • Anyplace where people are in close proximity
  • Sexually transmitted (crabs)
• Scabies
  
  • See scratch marks
  • Like wet areas (in cracks of body)
  • Burrow into skin

Question 5

Giardia

Answer 5

Giardia = diarrhea (not bloody), tx with metronidazole

• Looks like a professor
• Ingest cysts

Question 6

Toxoplasmosis

Answer 6

Toxoplasmosis = cats, pregnant women, HIV to AIDS, mono symptoms

• Litterbox
• 1% develop disease
  
  • Immunocompromised
  • Pregnant women (fetus) - 1st trimester is most dangerous
• AIDS defining illness: if you have HIV and get this, then you change to AIDS no matter your viral load
• Symptoms:
  
  • Mono-like
  • Malaise, fatigue, fever

Question 7

Trichomoniasis

Answer 7

Trichomoniasis = trichomoniasis vaginalis, green vaginal discharge, smells rotten, STI, urban populations

• Gold standard is a culture
• Jerky movements
• If male is circumsized, there is no place for parasite to live

Question 8

Helminths (worms) - What is the difference between round and flat worms?

Answer 8

Helminths (worms)

• Roundworms
  
  • Nematodes
  • Non segmented
    
    • Ascaris lumbricoides (hookworms)
• Flatworms
  
  • Asymmetric in cross section
  • Segmented
    
    • Cestodes
    • Tapeworms
  • Non segmented
    
    • Trematodes
    • Flukes

Question 9

Ascaris lumbricoides

Answer 9

Ascaris lumbricoides = roundworm

• Ingest eggs
• Heavy infections lead to malnutrition and bowel obstruction

Question 10

Enterobius vermicularis

Answer 10

Enterobius vermicularis = pinworm, anal itching, kids, homelessness, scotch tape method

Question 11

Necator americanus

Answer 11

Necator americanus = Nematodes (roundworms) that penetrate the skin

• Eggs in feces
• Iron deficient anemia

Question 12

Hookworms

Answer 12

Hookworms = will not climb more than 6 feet, used to be very common until outhouses were invented

Question 13

Trichinella spiralis

Answer 13

Trichinella spiralis = undercooked meat containing cysts, can live in you for 10-20 years and you never know, live in muscles, no cure

• Pork, wild pigs, polar bears
• Tx will kill adults but not encysted larval forms

Question 14

Cestodes

Taenia saginata

Taenia solium

Answer 14

Cestodes = segmented flatworms, tapeworms

Taenia saginata = beef tapeworm

Taenia solium = pork tapeworm

Question 15

Schistosoma mansoni

Answer 15

Schistosoma mansoni = swimmer’s itch, liver fibrosis, trematodes that penetrate the skin

Question 16

Trypanosoma

American trypanosomiasis

Answer 16

Trypanosoma = tsetse fly, develop chancre, sleeping disease

American trypanosomiasis = kissing bug, rash on face from scratching, Chagas disease (no cure)

Question 17

Leishmania

Leishmania donovani

Answer 17

Leishmania = sandfly bite, causes chancre

Leishmania donovani = kala-azar (black fever)

Question 18

Plasmodium

Answer 18

Plasmodium = Malaria, African countries, sickle cell like anemia, lyses RBCs, mosquitos