Microbio Week 10 - Viruses Transmitted Fecal-Orally (Exam 3) Flashcards
What kind of capsid does adenovirus have?
Icosahedral
Where does adenovirus replicate?
GI tract
How does adenovirus spread?
Fecal-orally
Respiratory
Does adenovirus cause symptoms?
Not usually
Which two adenoviruses are known to cause gastroenteritis?
40 and 41
Adenovirus 40 and 41 infections are common in which people?
Children
What else can adenovirus cause besides gastroenteritis?
Respiratory infection
Eye infection
Which two adenoviruses infect military recruits and cause nasal congestion, cough, and malaise that can develop into pneumonia?
4 and 7
What adenovirus vaccine does the military give?
Live 4 and 7
What is the live adenovirus 4 and 7 vaccine coated with?
Gelatin
Where does the live adenovirus 4 and 7 vaccine replicate? Does this cause symptoms?
GI tract
Does NOT cause symptoms
Adenovirus can last on _________ and _________ for weeks and is easily spread from person-to-person
towels and surfaces
Which eye infection caused by adenovirus is found mainly in adults and is very contagious?
Epidemic keratoconjunctivitis
Epidemic keratoconjunctivitis involves inflammation of what?
The cornea
What kind of capsid does rotavirus have?
Icosahedral
What family is rotavirus in?
Reovirus
Rotavirus is __________ and can reassort its genome
segmented
Where are rotavirus, norovirus, and picornaviruses very stable? (and all naked viruses in this lecture)
Detergents
Stomach acid
Resistant to drying, can last on surfaces for days
Wide range of temperatures
Billions of virus particles/gram of stool are shed during peak infection of which virus?
Rotavirus
Is rotavirus systemic or local? Does it have a short or long incubation time?
Local
Short incubation time
Which people have the most severe rotavirus infections?
Children under 5
T/F: Adults infected with rotavirus are often symptomatic
FALSE, they are often asymptomatic
What occurs after rotavirus symptoms are gone?
Viral shedding
What does a viral protein of rotavirus act as?
An enterotoxin (like cholera toxin)
What is the cause of severe dehydration in young children and hospitalization?
Rotavirus
What kind of vaccine is available for rotavirus?
Attenuated
Which vaccine is very good at preventing severe complications from infections that result in hospitalization (95%) but works less well at preventing all infections (70-80%)?
Rotavirus vaccine
What kind of capsid does norovirus have?
Icosahedral
What family is norovirus in?
Calicivirus
Millions of viral particles are shed in vomit and billions in feces in which virus?
Norovirus
T/F: Norovirus is VERY infectious
True!
T/F: Unlike rotavirus, norovirus infects and causes disease in all ages
True
What virus causes millions of illnesses (19-21 million) each year in the US and is the leading cause of outbreaks of acute gastroenteritis?
Norovirus
Norovirus causes severe problems in which people?
Elderly and very young
Is norovirus systemic or local? Does it have a short or long incubation time?
Local
Short incubation
How long do norovirus symptoms last?
Very short (1-3 days)
How long is norovirus shed?
From time of symptoms - up to 2 weeks after you feel better
What kind of capsid does picornavirus (family) have?
Icosahedral
What viruses are within picornavirus family?
Poliovirus
Echovirus
Enterovirus
Rhinovirus
Coxsackievirus A and B
HAV
(PERCH)
How are enteroviruses spread?
Fecal-orally
Respiratory
Enteroviruses are _________, meaning they kill the cell they infect
lytic
When do picornaviruses have seasonality?
Summer/early fall
Which picornavirus causes poliomyelitis?
Poliovirus
Which picornavirus causes meningitis/encephalitis?
All enteroviruses
Which picornavirus causes acute flaccid paralysis?
Enterovirus 71 and 68
Where do enteroviruses replicate before they enter the blood and go to target organs?
GI tract and respiratory tract
What can prevent enteroviruses from entering the blood and reaching target organs, stopping the severe consequences of infection?
IgG
T/F: Most poliovirus infections are asymptomatic
True
Most who were infected with poliovirus had symptoms were sick for about a week, some progressing to ____________, but all recovered completely
meningitis
About 1% of all poliovirus infections had what?
Paralytic poliomyelitis
Those who had paralytic poliomyelitis from poliovirus infection had polio travel where? What did this cause?
Motor neurons -> anterior horn -> killed cells -> symptoms of spinal polio w/ limb paralysis
What did paralytic poliomyelitis from poliovirus infection also cause in some people?
Weakness of muscles involved in swallowing and breathing -> higher mortality than spinal polio
What are the 2 polio vaccines?
Sabin/oral
Salk/inactivated
What type of vaccine is the Sabin/oral polio vaccine?
Attenuated
Where does the Sabin/oral polio vaccine replicate?
The gut
In which polio vaccine is there a chance of getting polio from the vaccine itself?
Sabin/oral polio vaccine
What happens if you are exposed to wild-type polio but you are vaccinated with the Sabin/oral vaccine?
- You do NOT get infected
- Infection, disease, and spread of WT poliovirus to others is prevented
What type of vaccine is the Salk/inactivated polio vaccine?
Inactivated
Which polio vaccine is used in the US?
Salk/inactivated polio vaccine
What viruses are the #1 cause of viral meningitis?
Enteroviruses
What happens if you are exposed to wild-type polio but you are vaccinated with the Salk/inactivated vaccine?
- You become infected, but IgG prevents disease
- Can be spread to others fecal-orally
What viruses can cause viral meningitis?
Enterovirus
Echovirus
Coxsackievirus A and B
Viral meningitis can occur at any age, but is very common in which people?
Children
T/F: Unlike bacterial meningitis, enteroviral meningitis resolves without treatment, with most having no lasting side effects
True
Besides meningitis, what else can enteroviruses cause?
Encephalitis
(most recover completely if the encephalitis occurs outside the neonate stage)
What picornaviruses cause hand, foot, mouth disease?
Coxsackievirus A
Enterovirus 71
Where are ulcerations/lesions from hand, foot, mouth disease found?
Mouth/pharynx
Soles of feet
Palms
What virus is endemic in East and Southeast Asia and causes hand, food, and mouth disease?
Enterovirus 71
What can Enterovirus 71 cause?
Severe neurologic complications
What virus causes herpangia?
Coxsackievirus A
Lesions in herpangia are similar to HFMD, but are limited to what part of the body?
Posterior oral cavity
(does not involve rest of body)
What virus causes myocarditis/pericarditis?
Coxsackievirus B
What does Coxsackievirus B start as?
Respiratory infection
Generalized infections of newborns can happen if the mother has an ___________ infection during the last week of pregnancy or if a newborn gets an ___________ infection shortly after birth
enterovirus; enterovirus
What happens if the newborn gets an enteroviral infection?
Spreads to multiple organs with high mortality rate
Why does the timing of infection in pregnancy matter?
If the mother can form ABs and transfer them to the fetus, the baby will be protected from the virus spreading in the blood to target organs
What happens if enterovirus symptoms occur a week before delivery?
Maternal ABs are made -> transferred through placenta -> baby protected
What family is rhinovirus in?
Picornavirus
Can rhinovirus be transmitted fecal-orally?
No
What inactivates rhinovirus?
Low pH
What temperature does rhinovirus prefer to grow at? What is this ideal for?
33 degrees, ideal for upper respiratory tract
T/F: There are many types of rhinovirus (>200), and most people are frequently reinfected and symptomatic throughout life
True
What is the primary cause of common cold?
Rhinovirus
High amounts of rhinovirus are found where?
Nasal secretions
Green nasal secretions are present in rhinovirus infections and indicate the presence of what?
Neutrophils
What is a significant route of rhinovirus infection?
Hand-to-face
Which picornavirus causes myocarditis/pericarditis?
Coxasackievirus B
Which picornaviruses cause respiratory infections?
All enteroviruses
Rhinovirus
Which picornaviruses cause generalized infections of newborns?
Coxsackievirus B
Echovirus
