Martin Flashcards Preview

Week 18 > Martin > Flashcards

Flashcards in Martin Deck (17)
Loading flashcards...
1

Classicfications of Parasites:

  • Protozoa:
    • Subgroups
      • Amoeba 
      • Flagellates
      • Sporozoa
      • Ciliates
  • Stamenopila
    • Blastocystis spp
  • Helminths (or worms
    • subdivided into:
      • Nematodes (round worms)
        • intestinal, blood and tissue nematodes
      • Trematodes (flatworms)
        • aka flukes
        • intestinal, blood, tissue
      • Cestodes 
        • tapeworms
        • intestinal and tissue cestodes 

2

Trophozoite

  • Active protozoal parasite
  • Feeding stage

3

Cyst

  • Infectious form of protozoan parasite
  • cell wall
  • condensed

4

Cilia

  • small hair-like processes on cell surface
  • composed of  (9x2)
    • 9 pairs of microtubules around a core of 2. microtubules
  • Cell movement

5

Definitive Host

  • Final host in sexual/adult life cycle

6

Intermediate host

  • Host in which parasite passes its larval or nonsexual 

7

What are the Different types of Parasites:

-pathogenic species

  • Amebae
  • Flagellates
  • Ciliates
  • Sporozoa

8

Protozoa: Amoeba

  • Enteric pathogen
    • pathogenic: Entamoeba Hystolytica
      • Diarrhea
      • local tissue dmage
      • liver abcesses (less frequent)
    • Nonpathogenic- asymptomatic 
      • E. dispar
      • E. hartmanni
      • E. coli
  • Fecal oral route
  • Unicellular organisms
    • asymmetric morphology
  • Motility:
    • pseudopod extension and retraction
  • Trophozoites
    • active replicating stage
    • nuclear morphology and cytosol appearnce used for ID in fecal smear
  • Cysts
    •  infective stage
    • dormant stable
    • nuclei number and morphology used for ID
  • Reproduction:
    • Binary cell division
      • mitosis
  • Colonize GI tract
  • Detection:
    • Stool specimen:
      • all amebae
      • presence of cyst or trophozoite
    • Enzyme Immunoassays (EIAs)
      • detect antigens
      • only E. histolytica

9

Entamoeba Hystolytica: Pathogenesis

  • 10-20% become sick
  • Mild symptoms:
    • loose feces
    • stomach pain
    • stomach cramping
  • Amebic dysentery
    • severe infection
    • invades the wall of large intestine
    • Stomach pain
    • bloody stools
    • fever
  • Rarely invades the liver and forms abscess
  • Can spread to lungs or brain
    • uncommon
  • Prevention:
    • adequate water treatment
    • clean fruits and vegetables before consumption

10

Protozoa: Mucosal Flagellates

  • Unicellar organisms
  • Motile:
    • Flagella
  • Replicate:
    • binary cell division (Mitosis)
  • 3 species:
    • G. Lamblia
      • form cysts
      • GI parasite
        • fecal oral route
    • D. fragilis
      • form cysts
      • Gi Parasite
        • Fecal oral route
    • T. vaginalis
      • no cysts
      • Urogenital Parasite
        • sexual contact 
  • Diagnostic:
    • cell morphology
    • flagella number and location
    • cyst formation

11

G. Lamblia 

Mucosal Flagellates

  • Form Cysts
  • Gi Parasite
    • fecal-oral route
  • Trophozoites
    • pear shaped
    • concave "sucking disk"-adhere to GI tract
    • 2 curved rods below the nuclei
    • 8 flagella
  • Cysts:
    • ovoid
    • 4 nuclei 
    • central fibrils
  • Acute Sympotoms:
    • Diarrhea
    • gas
    • Greasy stools that float
    • stomach crmaps
    • Upset stomach or N & V
    • Dehydration
  • Reservoir:
    • asymptomatic=carrier

12

T. Vaginalis

Mucosal Flagellates 

  • No Cysts
  • Urogenital parasite
    • sexual contact
  • Trophozoite Only (no cysts)
    • pyriform 
    • nucleus contains chromatin granules and small karyosome
    • Undulating membrane
      • extends half-way down parasite
    • Flagella
      • extend from anterio of parasite 
  • Diagnostic:
    • Jerky MOtion
      • highly motile
  • UTI
    • In men:
      • itching/irritation 
      • Burning after urinatin
      • Discharge
    • Women:
      • itching, burning, redness, or soreness of genitals
      • Discomfort with urination
      • change in vaginal discharge
        • thin discharge or increased volume
        • clear, white, yellow, green
        • fish smell
  • Unpleasant sex
  • without treatment:
    • can last months to years

13

D. Fragilis

Mucosal Flagellates 

  • Form Cysts
  • GI parastie
    • fecal oral contamination

14

Protozoa: Intestinal Ciliates

  • Balantidium coli
    • only ciliate human pathogen
    • GI parasite
      • fecal oral route
    • asymptomatic (mostly)
      • pts with other serious illness can have:
        • persistent diarrhea
        • abdominal apin
        • perforated colon
    • rare in US
  • trophozoites
    • unicellular
    • cilia
  • Cysts
    • infectious form
  • Symptoms: (amebiasis like)
    • Abdominal pain
    • Nausea
    • diarrhea
  • May cause tissue damage and intestinal ulceration in large intestine 
  • Reservoir
    • Swine
      • monkeys (less common)
  • Diagnosis:
    • stool sample
      • presence of trophozoites and cysts
  • Prevention: Endemic tropical countries
    • good hyigene
    • wash all fruits and vegetables

15

Protozoa: Intestinal Sporozoa 

Cryptosporidium spp.

  • spread via:
    • water systems 
    • fecal oral route
  • Self-limiting disease (<10 days)
  • AIDs patients:
    • diarrhea (50 days)
    • disseminated infections
  • Normal Symptoms:
    • severe watery diarrhea
      • dehydration
      • weightloss 
    • low grade fever
    • abdominal cramp
    • fatigue
    • N & V
    • epigatric or Right upper quadrant tenderness
  • Diagnossi:
    • fecal samples
      • Acid fast stain
      • oocysts

16

Blood and Tissue Protozoa:

  • Sporozoa:
    • Plasmodium: Malaria
    • Babesia: B. microti
    • Toxoplasma gondii
  • Flagellates
  • Most commonly detected by staining blood and tissues
  • Require an arthropod vector for spread and to complete life cycle

17

Babesiosis: 

Babesia microti (in the US)

  • infect and destroy RBCs
  • Ixodes scapularis Tick
    • aka Blacklegged ticks or Deer ticks
    • spread by young nymph stage
      • occurs during warm months
      • woods, brush or grass
    • Very small tick
  • Mainly Northeast and Upper midwest
    • peak during warm months
  • Range from Asymptomatic to life threatening
  • Non-specific flu like symptoms:
    • fever
    • chills
    • sweats
    • headache
    • body aches
    • loss of appetite
    • nausea
    • fatigue
  • Can cause hemolytic anemia
    •  jaundice
    • dark urine
  • Treatable and Preventable