Viral/Fungal Pathogens GI

Question 1

Mumps S/S + Epi + Diag + Tx

Answer 1

• B symptoms; Parotitis; Orchitis, Mastitis, Pancreatitis, deafness
• Most Infectious 3 Days before S/S start; Onset 16-18 days after infection
• TR-PCR; IgM ELISA
• Most resolve within 2 weeks; No antivirals available

Question 2

Warning signs bacterial Diarrhea

Answer 2

• High Fever
• Blood/mucous in stool
• severe abdoinal pain
• > 6 stools/d

Question 3

Rotavirus Virology

Answer 3

• Naked dsRNA tripe layer icosahedral

- “Spoked-wheel” appearance

Question 4

Rotavirus Presentation

Answer 4

• <5 YO
• S/S 2 Days after exposure
• Vomiting + Watery Diarrhea 3 - 8 Days

Question 5

RotaVirus PAthogenesis

Answer 5

NSP4 enterotoxin induces Ca-mediated Cl- secretions into lumen + release of cytokines

Question 6

Rotavirus Diagnosis + Tx/Vaccines

Answer 6

• Direct ELISA
• Latex agglutination test
• RT-PCR
• Immunichromatographic LFA
• Tx: Fluid/electrolyte Therapy
• Vaccines: Rotarix (2 + 4 months) and RotaTeq (2, 4, + 6 months)

Question 7

Caliciviral Diarrheal Disease (CDD) Virology

Answer 7

• Norovirus + Sapovirus

- Naked ssRNA linear icosahedral

Question 8

Star of David morphology

Answer 8

Sapovirus

Question 9

CDD Presentation

Answer 9

• S/S: N/V; acute-onset non-bloody diarrhea; cramping; myalgia, + fever
• Lasts 12-60 hours

Question 10

4 factors that make rapid spread of Norovirus possible

Answer 10

1. High environment stability
2. Fecal-oral transmission
3. Lack of durable host immunity
4. Low infectious dose

Question 11

Norovirus/Sapovirus PAth

Answer 11

Infects intestinal cells and damages them which prevents water absorption

Question 12

CDD diagnosis

Answer 12

• Clinical

- RT-PCR

Question 13

Kaplans Criteria Noravirus outbreak

Answer 13

• Vomiting in more than half of symptomatic cases
• Mean (or median) incubation period is 24-48 hours
• Mean (or median) duration of illness is 12-60 hours
• No bacterial pathogen isolated from stool

Question 14

Astrovirus Virology

Answer 14

• Naked + sense linear ssRNA icosahedral

Question 15

Astrovirus Presentation + Tx

Answer 15

• incubation 405 days
• S/S Last 2-3 days: mild diarrhea, N/V, fever, malaise, abdominal pain
• Tx: Rehydration Therapy; suuportive

Question 16

Astrovirus Path

Answer 16

• NO inflammation/cell death

- Disrupts tight junctions leading to ion leakage; Capsid enterotoxin causes diahhrea as well

Question 17

Adenovirus Presentation

Answer 17

• incubation 3-10 days
• S/S last 1-2 weeks: Diarrhea, N/V, Fever; Conjuctivitis
• Secreted in stool for months after infection

Question 18

Adenovirus Virology

Answer 18

• Icosahedrasl Naked linear dsDNA

Question 19

Microsporidiosis background

Answer 19

• Enterocytozoon bieneusi and Encephalitozoon intestinalis
• Pigs reservoir contaminated water
• Kills cell by multiplying inside cell until lysis

Question 20

Microsporidiosis S/S

Answer 20

• Non-bloody N/V, abdominal pain, fever

* Chronic in AIDS patients -> Gallbladder disease

Question 21

Microsporidiosis Tx for AIDS patients

Answer 21

E. bien: Fumagillan

E. Intest: Albendzaole

Question 22

Mycetismus GI

Answer 22

• Toxic GI mushrooms
• N/V; diarrhea
• Tx Supportive

Question 23

Mycetismus Nervosa/ Amanita Phalloides

Answer 23

• Amatoxin Poisoning
• Acute GI distress within 24H and Hepatotoxicity 3-4 days after
• Death one week after
• • “Death Cap” mushroom - 20% mortality
• Amatoxin a + B; selective RNAPM inhibitors
• Tx: Gastric decontamination; activated charcoal; Supportive care

Question 24

Aflatoxicosis

Answer 24

• Aspergillus Flavus/parasiticus
• Crop production/storage
• Path: Aflatoxins -> epoxide -> DNA mutagenesis + immuneosuppression
• Tx: Supportive care

Question 25

Coprinus Syndrome

Answer 25

- C. Atramentarius - Edible mushroom ingested w/ Alcohol - Disulfuram-like reaction via production of Coprine mycotoxin - S/S: N/V, SOB, headache, vertigo. tachycardia + Flushing - "Alcoholi flush reaction" - Tx: Supportive