Foodborne Viral Diseases Flashcards
T/F: Bacteria causes more foodborne illness than viruses do
False. Viruses are the most common cause of foodborne illness.
T/F: Hepatitis A outbreaks are of concern because they spread quickly and can lead to a decent number of fatalities.
False. Hep A is usually self limiting and most infections are asymptomatic.
Hepatitis A accounts for ___% of hepatitis infections worldwide
90%
Who/what is the reservoir for Hep A?
Humans are the most important. Non human primates can also possibly transmit it, but this isn’t a huge issue
Where are you more likely to see clinical disease due to HAV?
In more developed countries
How is HAV transmitted?
Directly via fecal-oral transmission and through a vehicle (food or water contaminated with feces).
How long is the incubation period for HAV?
about 28 days
How is HAV treated?
supportive care mostly, as this disease is self limiting and doesn’t kill people
How is HAV prevented?
Vaccination to increase resistance and reduce the reservoir, target the vehicle with proper food handling, sewage and sanitation, and blocking transmission.
What virus is also known as winter vomiting disease?
Norovirus.
What virus is the most common cause of foodborne illness worldwide?
Norovirus.
Who/what is the reservoir for Norovirus?
people. They excrete it through renal material and shed 18 hrs post infection, for 13-56 days.
T/F: Once people are exposed to norovirus, they are less likely to become infected again, as they build immunity.
FALSE. There are various strains of this virus, and cross protection between strains is poor.
How is norovirus transmitted?
Directly via fecal-oral route or through a vehicle, like contaminated food or water or fomites contaminated with feces.
What is the incubation period of norovirus, and how long do people stay sick?
incubation - 12-48 hours, duration - 24-72 hours
What are the clinical signs of noro?
nausea, acute onset vomiting, and watery, non-bloody diarrhea.
What do you look for to determine if an outbreak was caused by noro?
mean illness duration 12-60 hrs, mean incubation 24-48 hours, more than 50% of people vomiting and no bacterial agent found.
MUST FIND ALL 4
How is noro treated?
supportive care
How is noro prevented?
proper food handling and preparation most important, proper sewage and water treatment, and personal hygiene and hand washing.
T/F: Norovirus outbreaks are often small.
False. They are often quite large due to multiple forms of transmission, prolonged shedding, stability of the virus in the environment, and lack of cross protective immunity.
What is the likelihood of you contacting gastroenteritis due to noro on a cruiseship?
less than 1%
What virus is the most common cause of severe diarrhea in children around the world?
rotavirus
When are rotavirus outbreaks typically seen?
in the winter
Who/what is the reservoir for rotavirus?
people (through feces) and many animal species
How is rotavirus transmitted?
fecal-oral transmission (moral of this class is to wash yo damn hands, ya nasties), and through vehicles like food, water, or fomites contaminated with feces.
How long is rotavirus in the environment?
can last up to weeks in the enviro. makes it a problem in places like daycares
How long is the rotavirus incubation period? How long are people usually sick for?
incubation: less than 48 hrs, duration: 3-7 days
Is there a vaccine against rotavirus?
yes!
How can you prevent rotavirus, aside from the vaccine?
wash your hands, and cook food appropriately.
Other viral agents have a mean incubation period of what? How long is the illness?
variable incubation, usually 10-70 hours. lasts 2-9 days
T/F: compared to bacterial illnesses, viral illnesses usually have more vomiting and less diarrhea, shorter duration of symptoms, and have a shorter incubation periods.
True.
