Viral Foodborne Diseases Flashcards Preview

RUSVM Epidemiology > Viral Foodborne Diseases > Flashcards

Flashcards in Viral Foodborne Diseases Deck (36)
1

true/false: viruses are the most common cause of foodborne illness

true

2

true/false: testing for viral etiologies of diarrheal disease is commonly done

false

3

pathologic viruses

Hepatitis A virus
Norovirus group
Rotavirus
Other viral agents (astroviruses, adenoviruses, parvoviruses)

4

Hepatitis A

accounts for 90% of viral hepatitis infections worldwide
shed into bile → Exits via feces
Majority of infections are asymptomatic
Infection in infancy or childhood is asymptomatic

5

true/false: true number of Hepatitis a infections is unknown

true

6

Hepatitis A reservoir

People: most important
possible non human primates

7

Hepatitis A: high endemicity

In least developed countries
poor socioeconomic conditions
Entire population is infected as children minimal clinical disease

8

Hepatitis A: low endemicity

developed countries, better sanitation reduces transmission
Seroprevalence is lower
Often see more outbreaks: adults susceptible

9

Hepatitis A: transmission

direct: fecal-oral (most important)
vehicle: food, water contaminated with feces

10

Hepatitis A: clinical signs

Related to hepatitis
Diarrhea, dark urine, jaundice, and flu‐like
symptoms
Nausea, anorexia, fever, malaise, or abdominal pain

11

Hepatitis A: Case Definition/Diagnosis (CDC)

1. Discrete onset of clinical signs
2. Jaundice or elevated serum aminotransferase
AND
Either: Positive serologic test for IgM antibody to Hep A
OR: An epidemiological link to a lab confirmed case Household or sexual contact

12

Hepatitis A: treatment

supportive
post exposure prophylaxis

13

Hepatitis A: prevention

Target the host: vaccination
Target the vehicle
Block transmission

14

what is the most common cause of foodborne illness worldwide

Norovirus

15

percent of known foodborne illnesses caused by Norovirus

58%

16

Norovirus: reservoir

people

17

Norovirus: transmission

direct: fecal-oral
vehicle: food and water contaminated with feces, fomites

18

Norovirus: clinical signs

nausea
acute onset vomiting
watery non-bloody diarrhea with abdominal cramps

19

Norovirus: case definition/diagnosis

1. Kaplan Criteria used to determine if an outbreak was caused by Norovirus:
-Mean(median) illness duration: 12 – 60hrs
-Mean (median) incubation period: 24 – 48hrs
-More than 50% of people with vomiting
-No bacterial agent found
2. RT PCR of stool, vomit or environmental samples

20

Norovirus: treatment

supportive

21

Norovirus: prevention

Target the vehicle: Proper preparation, cooking and handling of food: MOST IMPORTANT
Block transmission: Personal hygiene and hand washing

22

true/false: Norovirus outbreaks are generally small

false:
Multiple potential modes of transmission
Prolonged asymptomatic shedding
Environmental stability of the virus
Lack of persistent cross‐protective immunity

23

restaurant workers

Low paid
No or poor benefits
Have to work when sick
Norovirus, Influenza

24

Noroviruses and cruise ships

The increase in gastroenteritis on cruise ships is primarily attributed to noroviruses
Noroviruses have caused large consecutive cruise ship outbreaks
Prompt implementation of disease control measures are key to controlling norovirus outbreaks

25

what is the most common cause of severe diarrhea in children around the world

rotovirus

26

Rotovirus: reservoir

people
many species of animals (livestock, monkeys)

27

Rotovirus: transmission

direct: fecal-oral
vehicle: contaminated food and water, fomites (virus is hardy-lasts for weeks in environment)

28

Rotovirus: hight risk for transmission

Children attending day care centres
Children in hospital wards
Parents or workers in day care or hospitals
Immunodeficient people

29

Rotovirus: clinical signs

In children 3 to 36 months of age
First infection after 3 months of age is most severe up until about 36 months
Diarrhea, in most cases is self limiting
May see temporary lactose intolerance
Dehydration, electrolyte imbalances

30

Rotovirus: case definition/diagnosis

no definitive case definition
Rotavirus antigen in stool detected with enzyme immunoassay (EIA)

31

Rotovirus: treatment

supportive

32

Rotovirus: prevention

target host
target vehicle
block transmission

33

Rotovirus: vaccination

children get infected very young
- 2 vaccines available (2-3 oral doses at 2 months of age)

34

by contrast bacterial illness:

Usually have a moderate incubation period, lack of vomiting, and somewhat longer duration of illness

35

by contrast parasitic illness:

Usually have a longer incubation period (1 to 2 weeks) and a longer duration of illness (>2 to 3 weeks)

36

other viral agents include

Astroviruses, adenoviruses, parvoviruses