lecture 18 - food borne bacteria

Question 1

what are the characteristics of Polio?

Answer 1

• RNA genome and a protein capsid (non-enveloped)

- enterovirus (infection occurs via the fecal oral route)

Question 2

what is viremia?

Answer 2

the presence of viruses in the blood

Question 3

what occurs in 95% of polio cases?

Answer 3

only transient viremia occurs and the infection is basically asymptomatic

Question 4

what occurs in 5% of polio cases?

Answer 4

virus spreads and replicates in other tissues including muscle

Question 5

what are the symptoms of 5% of cases, where viremia occurs?

Answer 5

minor symptoms such as fever, headache, and sore throat

Question 6

what occurs in 1% of polio cases?

Answer 6

paralytic poliomyelitis occurs - this is a paralytic disease of when the virus enters the central nervous system and replicates in the motor neurons of the spinal cord, brain stem, and motor cortex

Question 7

what is the result of paralytic poliomyelitis?

Answer 7

temporary or permanent paralysis

Question 8

where is endemic transmission of poliovirus still occuring?

Answer 8

Afghanistan, Nigeria and Pakistan

Question 9

what food products is poliovirus associated with?

Answer 9

milk and milk products

Question 10

what deactivates polio virus?

Answer 10

pasteurization of milk above 70C for 30 seconds

Question 11

what are the three serotypes of poliovirus?

Answer 11

PV1, PV2, PV3 - each have slightly different capsid proteins

Question 12

what is the common trait between all serotypes of poliovirus?

Answer 12

all extremely infectious

Question 13

where is PV1 most commonly found?

Answer 13

in nature - localized to regions of Pakistan and Afghanistan

Question 14

is PV2 still present?

Answer 14

no, most likely eradicated

Question 15

is PV3 still present?

Answer 15

has not been detected since 2012, so it is likely eradicated, in 2012 it was detected in Nigeria and Pakistan

Question 16

what are the characteristics of Hepatitis A Virus?

Answer 16

non-enveloped single-stranded RNA virus

Question 17

how is hepatitis A transmitted?

Answer 17

through a fecal oral route - usually spread by eating food or drinking water that is contaminated with infected feces

Question 18

what organ does hepatitis A infect?

Answer 18

the liver, can cause acute liver failure (mostly in the elderly)

Question 19

what are the symptoms of hepatitis A, and how long do they last for?

Answer 19

nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain. usually lasts around 8 weeks

Question 20

what is a common source of food for Hepatitis A to occur?

Answer 20

shellfish

Question 21

what group of people are usually asymptomatic for hepatitis A?

Answer 21

kids

Question 22

a single infection of hepatitis A virus leads to ____

Answer 22

lifelong immunity

Question 23

how is hepatitis A prevented?

Answer 23

HAV vaccine, proper hand washing and cooking

Question 24

what is the treatment for acute liver failure?

Answer 24

transplant

Question 25

where do outbreaks of HAV usually occur?

Answer 25

in moderately developed countries where young children have not been exposed, but vaccination is also not widespread

Question 26

how did the hepatitis A virus outbreak occur in North America?

Answer 26

frozen strawberries imported from Egypt

Question 27

HAV survives mild ____ and exposure to _____

Answer 27

pasteurization | high temperatures

Question 28

what was the Costco 2016 outbreak?

Answer 28

there was HAV contamination in Nature's Touch Organic Berry Cherry Blend in canada's Costco stores?

Question 29

what are the symptoms of HAV effects on the liver?

Answer 29

nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain

Question 30

how does HAV travel to the liver?

Answer 30

initially infection generally occurs in the intestine, but then HAV enters the bloodstream

Question 31

what cells can HAV multiply in, once in the liver?

Answer 31

hepatocytes

Question 32

HAV is excreted in ____ towards the end of the incubation period?

Answer 32

feces

Question 33

how is HAV diagnosed?

Answer 33

through the detection of IgM antibodies in the blood - IgM is only present following acute HAV infection

Question 34

what does the presence of IgG mean in HAV infection?

Answer 34

that the acute phase has passed, and the person is immune to further infection

Question 35

what is Norovirus (NoV)?

Answer 35

the most common cause of gastroenteritis, worldwide

Question 36

what are the treatments of Norovirus?

Answer 36

none - no vaccines or effective treatments

Question 37

what are the symptoms of Norovirus?

Answer 37

non-bloody diarrhea, vomiting, and stomach pain

Question 38

what is the typical recovery period of Norovirus?

Answer 38

1-3 days

Question 39

what are the characteristics of Norovirus?

Answer 39

positive-sense RNA, non-enveloped

Question 40

how is norovirus transmitted?

Answer 40

airborne transmission due to vomiting. Virus found in vomit and germs can infect other people.

Question 41

how long can people be contagious for with Norovirus?

Answer 41

for as long as 2 weeks after recovery

Question 42

where do Norovirus outbreaks occur?

Answer 42

mainly long-term care facilities, cruise ships, schools, party/events, restaurants, and hospitals

Question 43

what foods are Noroviruses mainly found in?

Answer 43

shellfish and salad ingredients

Question 44

how do noroviruses enter food?

Answer 44

from a single infected person

Question 45

what are the characteristics of Rotavirus?

Answer 45

a non-enveloped virus, double stranded DNA

Question 46

rotaviruses are the most common cause of ____ among infants and young children

Answer 46

diarrheal disease

Question 47

what age group is Rotavirus mortality rate highest?

Answer 47

children younger than 5 years - mainly in Africa

Question 48

what is the significance of the Rotavirus vaccine?

Answer 48

licensed for use in 1998 and was thought to be 80-100% effective in preventing severe diarrhea. however, the vaccine was removed from the market in 1999 because it increased the risk of intussusception (type of bowel obstruction) in one in every 12,000 cases. a new vaccine was administered in 2006

Question 49

what are the overall symptoms of Rotavirus?

Answer 49

nausea, vomiting, watery diarrhea and low-grade fever

Question 50

what is the incubation period of Rotavirus in children?

Answer 50

approximately 2 days, and then symptoms. period of illness is acute

Question 51

what are the starting symptoms of Rotavirus?

Answer 51

vomiting, followed by four to eight days of profuse diarrhea

Question 52

what is the most common cause of death from Rotavirus?

Answer 52

dehydration from diarrhea