GI Acute Non-Inflammatory: Viruses + Cryptosporidium Flashcards Preview

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Flashcards in GI Acute Non-Inflammatory: Viruses + Cryptosporidium Deck (27):
1

describe the classification of rotavirus

11 segments of dsRNA non-enveloped

2

if a child is infected with rotavirus and is < ___ months or > ___ years, they are asymptomatic

if a child is infected with rotavirus and is < 6 months or > 5 years, they are asymptomatic; protection against diarrheal infectiono

3

describe how rotavirus is acquired and the incubation period

fecal-oral route or water-borne or air-borne

incubation: <48 hours (1-3 days)

4

desribe the pathogenesis of rotavirus

  • acquired via: fecal-oral route, water-borne, or air-borne
  • replication: epithelial cells of SI
    • shortening and blunting of villi, patchy irregularly intact mucosa, mononuclear cell infiltration of lamina propria
    • diarrhea results from the loss of absorptive area and the flux of water/fluid across the damaged surface
  • shed in feces
    • shedding may persist for 10 days or more
    • peak within 8 days

5

the replication of rotavirus takes place in ____

the replication of rotavirus takes place in epithelial cells of SI

6

the diarrhea caused by rotavirus results from _____

the diarrhea caused by rotavirus results from the loss of absorptive area and the flux of water/fluid across damaged surface

7

describe the clinical manifestations of rotavirus

  • sudden onset watery diarrhea with or without vomiting
  • up to 6 days
    • longer = immunocompromised
  • complications: dehydration could be severe and life-threatening

8

describe the detection of rotavirus

  • virus in stool peaks at day 3/4 of diarrhea
    • latex agglutination

9

describe the Sketchy

10

describe the Norwalk virus (Norovirus) classification

small, non-enveloped (+) ssRNA

11

most cases of norovirus occur during ____ (season)

most cases of norovirus occur during the winter

"winter vomiting disease"

12

describe the transmission of norovirus and the main vector for food-borne illness

  • transmission via:
    • primary = fecal-oral route
    • water-borne
    • food-borne
      • raw-shellfish

13

describe the pathogenesis of norovirus

  1. transmission via fecal-oral route, water-borne route, food-borne route (raw shellfish)
  2. virus multiplies in SI
  3. produces transient lesions of intestinal mucosa
  4. spares large intestine (NO fecal leukocytes)
  5. shed in feces

14

norovirus spares the ____ and therefore there are NO ____

norovirus spares the large intestine and therefore there are NO fecal leukocytes

15

describe the duration of clinical manifestations of norovirus infections

mild and brief: 24-48 hours following ingestions; lasts 24-60 hours

characterized by: abdominal cramps, myalgias, malaise, headache, nausea, low-grade fever & 1-2 days diarrhea 

16

norovirus is commonly associated with outbreaks on _____

norovirus is commonly associated with outbreaks on cruise ships

17

describe the Sketchy

18

describe the classification of adenovirus

non-enveloped dsDNA

icosahedral protein shell 

19

the main target of adenovirus is the ____

the main target of adenovirus is the respiratory tract

20

describe the classification of astrovirus

(+) ssRNA, non-enveloped

21

describe the 3 different types of diarrhea that Cryptosporidium spp. causes

  • self-limiting diarrhea (most common)
    • stomach cramps or pain, dehydration, nausea, vomiting, fever, weight loss
  • persistent diarrhea in endemic developing countries 
    • persistent diarrhea in children
  • chronic diarrhea in immunocompromised 

22

Cryptosporidium spp. is a frequent cause of ____ disease

Cryptosporidium spp. is a frequent cause of waterborne disease

  • drinking and recreational water

23

infection by Cryptosporidium occurs after ingestion of ____

infection by Cryptosporidium occurs after ingestion of thick-walled oocysts

24

after ingestion of oocysts, the ____ attach to and invade the epithelial cells of the SI where they develop into the ____

after ingestion of oocysts, the sporozoites attach to and invade the epithelial cells of the SI where they develop into the trophozoites

25

the ___ are the diagnostic stage of Cryptosporidium spp.

the thick-walled oocysts (also the infective form) are the diagnostic stage of Cryptosporidium spp.

26

describe the diagnosis of Cryptosporidium spp.

  • not routine O&P; must request
  • microscopic stool examination:
    • multiple stools collection on separate days
    • wet mounts
    • thick walled oocysts
  • differential staining = modified Ziehl-Neelsen

27

describe the Sketchy