L34: Fish and shellfish hygiene

Question 1

What is the usual toxin in fish?

Answer 1

Scombrotoxin

Question 2

What are the usual viruses in bivalves?

Answer 2

Norovirus or astrovirus

Question 3

WHat are the scombroid fish?

Answer 3

Tuna, mackerel, herring

Question 4

How does histamine form in fish?

Answer 4

Gram -ve bacteria convert histidine to histamine

Question 5

How soon do you get illness after histamine?

Answer 5

10 min - 2 hours

Question 6

What is primary control measure against histamine?

Answer 6

Rapid cooling after harvest

Question 7

Below what temp can Listeria grow?

Answer 7

5 degrees

Question 8

Which kind of seafood is associated with Listeria outbreaks?

Answer 8

Smoked

Question 9

Which kind of fish is botulism associated with?

Answer 9

Fin fish

Question 10

How can fermented whole fish cause botulism?

Answer 10

NaCl too low

Question 11

What is the definitive host of nematodes?

Answer 11

Marine mammals

Question 12

How do nematodes cause disease in humans?

Answer 12

Dies causing inflammation

Question 13

What is the definitive host of cestodes and trematodes?

Answer 13

Humans

Question 14

What must happen to fish products intended to be eaten raw?

Answer 14

Frozen

Question 15

What does freezing fish not prevent?

Answer 15

Allergic reactions to larval proteins

Question 16

What temperature and for how long must fish be frozen?

Answer 16

-20 for 24 hours or -35 for 15 hours

Question 17

Which effect may possibly allow pathogenic vibrio spread?

Answer 17

El nino

Question 18

What is the problem with the estuaries/inlets used for shellfish cultivation?

Answer 18

Also used for sewage disposal

Question 19

What three diseases can biotoxins cause?

Answer 19

Paralytic, diarrhetic, amnesic shellfish poisoning

Question 20

WHich kind of shellfish poisoning is neurotoxic?

Answer 20

Paralytic

Question 21

Which kind of shellfish poisoning is neurotoxic?

Answer 21

Amnesic

Question 22

What is norovirus incubation like compared to bacteria?

Answer 22

Longer

Question 23

What is norovirus immunity like?

Answer 23

None - can mutate rapidly

Question 24

Why do oysters have more microbiological issues?

Answer 24

Consumed raw

Question 25

Why does norovirus peak in winter in bivalves?

Answer 25

In sewage in winter and taken up

Question 26

Whick kind of microorganisms are not present in animal waste contamination?

Answer 26

Viruses

Question 27

What are the four types of bivalve harvesting areas?

Answer 27

A, B, C, prohibited

Question 28

What does the bivalve risk assessment assess?

Answer 28

Faecal contamination in the area

Question 29

What are G1 norovirus levels like compared to G2, especially in which season?

Answer 29

Lower, esp in winter

Question 30

What is correlation between E Coli and norovirus like in individual samples?

Answer 30

Lack

Question 31

What is correlation between E Coli and norovirus like on a site by site basis in winter?

Answer 31

Better/best

Question 32

What is depuration?

Answer 32

Bivalve purification in seawater

Question 33

What is removed rapidly during depuration?

Answer 33

E Coli

Question 34

What is hardly removed at all in depuration?

Answer 34

Norovirus

Question 35

Which is the only part of the chain that does not have HACCP?

Answer 35

Primary production

Question 36

What is traceability of bivalves like?

Answer 36

Registration document at harvest, ID on packet

Question 37

How many main species of Vibrios are there?

Answer 37

Three

Question 38

What % of pathogenic Vibrios are removed at depuration?

Answer 38

40-50%

Question 39

Which Vibrios contaminate seafood, esp raw/undercooked bivalves?

Answer 39

Vulnificus and parahaemolyticus

Question 40

How quickly does death occur following Vibrios?

Answer 40

2 days

Question 41

How does Vulnificus contamination occur?

Answer 41

Via GI tract or wounds

Question 42

What does vulnificus cause in humans?

Answer 42

Primary septicaemia or wound infections

Question 43

WHich people are especially affected by vulnificus?

Answer 43

Older men with liver problems

Question 44

What does parahaemolyticus risk depend on?

Answer 44

Unrefrigerated time because rapid proliferation

Question 45

Which parahaemolyticus strains cause gastroenteritis?

Answer 45

Those with haemolytic activity