Respiratory viruses - part 2 Flashcards
Although we don’t know the pathogenesis of RSV infection, what appears to be involved?
immunologic factors
Community outbreaks of RSV occur _______ in the ______ weather and affect about __% of families
annually
colder
50%
What test can we use on respiratory secretions from RSV infected individuals to determine viral antigens?
real time PCR
When adults get RSV infection, what do they present with?
a flu-like illness
What is the treatment for RSV?
provide oxygen and mechanical ventilation as necessary, and aerosolized ribavirin (don’t need to know this tbh)
Describe the morphology of adenoviruses and where they replicate?
Naked, dsDNA viruses
since they have a DNA genome, they replicate in the nucleus
How are adenoviruses released?
Released by host cell destruction - causes epithelial cell necrosis
What is very important to remember about adenovirus?
THEY CAN CAUSE ANY SYMPTOM
what percentage of adenovirus infections cause any symptoms?
45%
Approximately __% of acute febrile illness in childre under two is attributed to adenovirus.
10
What are adenoviruses capable of, regarding replication?
How are they spread?
latency
spread by either respiratory or fecal-oral routes
Is there such thing as a cold?
no; there is a common cold syndrome however which means URT infection with prominent nasal involvement
What is the morphology of Rhinoviruses? How are they distinguished from enteroviruses?
Naked picornaviruses
distinguished from enteroviruses by acid lability and an optimum temperature of replication of 33°C
The fact that there are 108 rhinovirus serotypes ensures what?
that people remain susceptible to infection throughout life
How are rhinoviruses transmitted?
via direct contact (no through fomites = inanimate objects)
What do Rhinoviruses cause in terms of damage?
mucosal cell damage and mediators of inflammation
Why are colds self-limiting and why can you not get another cold directly after?
The infected nasal mucosal cells get infected and sloughed. No cells left to infect - virus does not persist, cannot get reinfected.
If a “cold” lasts longer than 10 days, what is the most likely culprit?
bacterial sinusitis
What can follow a cold?
secondary bacterial infections
The acute symptoms of rhinitis, nasal obstruction and sore throat are thought to be a combination of what? (Rhinovirus)
mucosal cell damage and soluble mediators of inflammation, esp. bradykinin
What are two things that definitely help with colds?
Ginseng extracts
Zinc supplements - lessen duration of colds
What are some drugs that can be used to treat colds?
Analgesis, decongestants and anti-histamines
What is useful for treatment of colds in infants?
nasal aspirator
Describe the morphology of coronarviruses.
enveloped, ss RNA virus
How do coronaviruses look under the microscope (EM)?
solar, corona-like
What is the major etiologic agent of SARS and common cold syndrome?
coronavirus
How are coronaviruses transmitted?
aerosols
What is the incubation period of coronavirus?
3 days
What do coronaviruses usually cause?
mild common cold symtpoms
When is the blood test positive for SARS coronavirus?
20th day of illness (ELISA)
What is the suspected animal vector of the SARS coronavirus?
Civet at
What is the Civet cat notable for?
Anal gland secretions - highly prized for world’s most expensive perfumes and coffees
What are the reservoirs of MERS?
bats and camels
What does MERS stand for?
How does it spread?
Middle Eastern Respiratory Syndrome
we don’t know if it spreads human to human
