Foodborne Viral Infections Flashcards
Give me the characteristics of Poliovirus
- RNA genome
- Protein capsid (non-enveloped)
- Is an enterovirus (infection occurs via the fecal oral route)
- 95% of the time only transient viremia occurs and infection is asymptomatic
In 5% of cases where viremia occurs (poliovirus) symptoms include:
- fever
- headache
- sore throat
- in 1% of cases paralytic poliomyelitis occurs
what is paralytic poliomyelitis :
- a paralytic disease of when the virus enters the CNS and replicates in the motor neurons of the spinal cord, brain stem, and motor cortex
- it results in the destruction of motor neurons and temporary or permanent paralysis
Poliovirus can be associated with the consumption of which product?
milk and milk-products
pasteruization of milk at above 70C for 30s deactivates the virus
What are the 2 types of vaccines used to prevent poliovirus?
- Inactivated poliovirus vaccine (IPV)
- Oral poliovirus vaccine (OPV)
What are the 3 serotypes of poliovirus and how do they differ:
-PV1 (most common in nature)
-PV2 (likely eradicated)
-PV3 (likely eradicated)
they each have a slightly different capsid protein
Give me the characteristics of Hepatis A Virus (HAV)
- single stranded RNA
- non-enveloped
- spread through fecal oral route, but mostly affects the liver, causing viral hepatitis
- most cases have few or no symptoms (especially in young children)
What happens when symptoms occur in HAV
- symptoms can last 8 weeks
- include nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain
- acute liver failure may occur mostly in elderly
How can HAV spread ?
- spread by eating food or drinking water that is contaminated with infected feces
- shellfish which have not been sufficiently cooked are a relatively common source
- it can also spread from an infected person if there is sustained close contact
- kids that are asymptomatic can still infect others
- **-a single infection leads to lifelong immunity ***
What can you do for HAV prevention?
- HAV vaccine (very effective and appears to give lifelong immunity)
- the majority of children in the developing world have been infected and are thus immune by adulthood
- hand washing and properly cooking food in areas where the disease is endemic are also important
For HAV, recovery usually occurs without ongoing liver disease , though the treatment for acute liver failure is a ________
transplant
HAV outbreaks in North America occured do to which type of product?
frozen strawberries (fronzen fruits)
HAV survives ____________ and exposure to ______________ it is resistant to desiccation and can remain infectious for several months on frozen foods
mild pasteurization
high temperatures
HAV infection generally occurs in the ________________, by then HAV enters the_________
intestine
bloodstream
(the blood carries the virus to the liver where it can multiply in hepatocytes)
HAV is excreted in large numbers in the stool about ________ prior to the appearance of symptoms
11 days
Diagnosis of HAV is made by the detection of ______ in the blood
IgM antibodies in the blood - IgM is only present following acute HAV infection
The presence of ______ means that the acute phase has passed (HAV), and the person is immune to further infection
IgG
Talk to me about Norovirus :
- It is the most common cause of gastroenteritis world wide and in Canada
- There are no vaccines or effective treatments
- Infections cause non-bloody diarrhea, vomiting and stomach pain
- Typically recovers in 1-3 days
- positive-sense RNA, non-enveloped
Where is the illness easily spread (Noroviruses):
- in group settings where people are in close contact
- schools
- hospitals
- childcare facilities
- nursing homes
- cruise ship
(Norovirus) : vomiting appears to allow the virus to spread via ____________
airborne transmission
________ and _______ ingredients are most implicated in norovirus outbreak
shellfish and salad
any type of foods can also be contaminated by infected food handlers
Give me the characteristics of Rotavirus:
- non-enveloped virus
- double stranded DNA
- most common cause of diarrheal disease among infants and young children
- nearly every child in the world is infected with rotavirus once by the age of 5
why was the 1998 Rotavirus vaccine removed from the market in 1999
because it increased the risk of a type of bowel obstruction in one in every 12,000 cases
Talk to me about the symptoms of rotavirus :
- nausea
- vomiting
- watery diarrhea
- low-grade fever
- incubation period of 2 days before symptoms appear in the child
- the period of illness is acute
- symptoms start with vomiting followed by 4 to 8 days of profuse diarrhea
- dehydration is more common in rotavirus infection than in most of those bacterial pathogens and is the most common cause of death related to rotavirus infection
