lecture 18 - food borne bacteria Flashcards
what are the characteristics of Polio?
- RNA genome and a protein capsid (non-enveloped)
- enterovirus (infection occurs via the fecal oral route)
what is viremia?
the presence of viruses in the blood
what occurs in 95% of polio cases?
only transient viremia occurs and the infection is basically asymptomatic
what occurs in 5% of polio cases?
virus spreads and replicates in other tissues including muscle
what are the symptoms of 5% of cases, where viremia occurs?
minor symptoms such as fever, headache, and sore throat
what occurs in 1% of polio cases?
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
what is the result of paralytic poliomyelitis?
temporary or permanent paralysis
where is endemic transmission of poliovirus still occuring?
Afghanistan, Nigeria and Pakistan
what food products is poliovirus associated with?
milk and milk products
what deactivates polio virus?
pasteurization of milk above 70C for 30 seconds
what are the three serotypes of poliovirus?
PV1, PV2, PV3 - each have slightly different capsid proteins
what is the common trait between all serotypes of poliovirus?
all extremely infectious
where is PV1 most commonly found?
in nature - localized to regions of Pakistan and Afghanistan
is PV2 still present?
no, most likely eradicated
is PV3 still present?
has not been detected since 2012, so it is likely eradicated, in 2012 it was detected in Nigeria and Pakistan
what are the characteristics of Hepatitis A Virus?
non-enveloped single-stranded RNA virus
how is hepatitis A transmitted?
through a fecal oral route - usually spread by eating food or drinking water that is contaminated with infected feces
what organ does hepatitis A infect?
the liver, can cause acute liver failure (mostly in the elderly)
what are the symptoms of hepatitis A, and how long do they last for?
nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain. usually lasts around 8 weeks
what is a common source of food for Hepatitis A to occur?
shellfish