Viruses in Lung Flashcards
Respiratory Viruses:
Start with Respiratory transimission–> replication in upper tract and you can have what three complications?
Upper and sometimes lower respiratory infections and diseases
Respiratory disease; serious such as pneumonia
replication leads to viremia in target organs
Influenza virus
_____subtypes of hemagglutinin (HA)
___ subtypes of neuraminidase (NA)
with both animal and human hosts playing key role in epidemiology
16
9
Explain difference between antiginetic drift and shift in regards to influenza virus
Drift happens with slowly, over years, with small changes to HA or NA while NP stays constant
Shift happens rapidly (one year) with one big shift in NA or HA
Flu Vaccine
- Each year make vaccine to ___ strains
- Post vaccine, body makes ____
- If you are exposed to any of those strains, anitB latch onto virus’s _______ and prevent flu from attaching to healthy cells
3 strains (2 for A 1 for B)
body makes antibodies
latch onto virus’s HA antigens
INfluenza virus genes are made of ____ making them more prone to mutations
If HA gene changes, so can the antiG that encodes it causing it to change shape… the antiB we got from flu vaccine no longer work, this is called
RNA
antigenic DRIFT
The genetic change that enables flu strain to jump from one animal species to another including human:
anitgentic SHIFT
W/out undergoing genetic change, a bird strain of influenza A can jump to another duck or even human, the new strain may further evolve and then can spread person to person… if so a flu _____ can arise
Pandemic
How does genetic mixing result in a new strain of influenza
A bird can pass influenza A to pig
A person can pass influenza A to same pig
If both viruses infect the same cell and the genes mix–> get new strain
New strain can spread intermediate host to human
The third way a bird host can get influenza to a human is if the influenza bird strain jumps to _____ and then to humans
human host
Influenza ____ result from antigenic shift
pandemics
H5N1 in 2014 was confirmed avian influenza that 393 people died from… is it easy to trasmit and how does it transmit?
What about H7N9?
does not transmit easily, people exposed to infected household poultry or contaminated environment
H7N9: doesn’t transmit easliy, killed 175
Influenza pathogenesis:
what type of disease is it?
How does it infect host?
How is it replicated?
Influenza - acute respiratory diseaes
Virus infects ciliated epi cells lining URT, trachea and bronchi
Replicates by destruction of respiratory epithelium
How does influenza cause cell damage?
From virus activation of cytotoxic T cells
***viremia doesn’t play major role in pathogenesis
Describe tracheal mucosa:
normally-
3 days post infection
7 days post infection
Normally: ciliated
3 days post: all cilia gone (susceptible to 2nd bacterial infection) and decreased clearance of gunk
7 days post: slow regrowth of cilia
Disease mechanism of A and B influenza viruses
- Where it established infection
- Cause of systemic symptoms and local symptoms
- key for immune resolution
- establishes infection in upper and lower RT
- Systemic symptoms from interferon and cytokine response to virus
Local from epithelial cell damage: to ciliated and mucus secreating cells
- •Interferon and cell-mediated immune responses (natural killer and T cells)
Antibody for future protection against influenza is specific for ____ and ____
which can undergo major ______ or shift and minor _____ or drift
HA hemagglutinin and NA neuramidase
minor (mutution:drift) and major (reassortment: shift)
Influenza B only undergoes what kind of changes?
minor antigenic changes
Influenza is normally self limited, for 3-7 days and is more sever in ____ and ____
What is our major cause of death with influenza?
young and old
death from secondary bacterial infections: S.penumonaie, S.aureues, H.influenzae
What rare complications can arise from influenza virus?
myositis and cardiac involvement
– Guillain-Barre’ syndrome
– encephalitis
– Reye syndrome
What are our three vaccine options for influenza?
a. formalin inactivated - mixture of prevalent antigenic types (hemagglutinin and neuramindase)
b. attenuated infectious viruses → intranasal administration
c. quadrivalent vaccine available 2013
Antiviral used to treat influenza that inhibits uncoating by blocking M2 protein
Amantadine adn imantadine (not used bc of high degree of antiviral resistance)
Antivirals to tx influenza that are neuraminidase inhibitors (inhibit release of progeny virus):
Zanamivir and Oseltamivir (Tamiflu)
Rhinovirus – key points
• Cause____% of common colds
• Antigenic diversity - _____ serotypes identified
RV-A (75 serotypes), RV-B (25 serotypes), RV-C (51 serotypes)
•_____ only natural host
50%
150
Humans
Rhinovirus infections are _________ and temperature sensitive between ____ and ___ degrees
infections are mild and self limiting grow better at 33 degrees then 37
How is Rhinovirus transmitted?
How is rhinovirus prevented and controlled?
Transmission via respiratory secreations/ individual to individual and FOMITES
PRevention and control: no antivirals no vaccines as of now, just handwashing and disinfectants
(has the canyon floor pore)
Resonsible for summer colds and flus: common cold symptoms, like fever, head ache and fatigue
Enterovirus
Enterovirus has what two syndromes? what vaccine or antivirals are available?
Respiratory tract infection and undifferentiated fever
no vaccine or antivirals available
EV-D68 is enterovirus 68, seen this year in october… what are the symptoms of this disease?
Saw flaccid paralysis, not sure why, spread via respiratory secreations from human to human and inactivated by low pH thus doesn’t replicate in GI tract
What type of illness do we see do we see in Enterovirus D68?
mild to severe respiratory illness, severe; difficulty breathing and wheezing particullarly bad in asthmatics.
Corona viruses causes what?
What symptoms do we see?
Is there a vaccine available?
cause common colds (second most prevalent cause representing 10 -15% of total)
- watery eyes, sneezing, nasal congestion, sore throat, sometimes fever, chills, headache, other aches, cough
• no vaccine available
Where in the body does Coronavirus infect?
• disease limited to upper respiratory tract, infects epithelial
cells (optimal temperature for viral growth is 33° to 35°)
Sudden Acute Respiratory Syndrome- what kind of virus?
• Fatality rate among people with illness - about ____
• Transmission mainly by:
Coronavirus
10%
f_ace-to-face_ contact , virus in respiratory secretions and feces, **not highly
contagious **
How was SARs controlled?
What was the source?
What tx/vaccines are available?
By containment
source = bats
No vaccines or antivirals available
MERS is what type of virus?
What besides humans does it infect?
How is it transmitted?
Coronavirus
infects bats and camels
Doesn’t pass human to human easily, it’s an RNA virus thus unstable
What symptoms/ disease results from MERS?
Disease: acute severe pnemonaie and renal failure~ people in serious cases tend to have underlying medical issues*
**nosocimial documented
Nosociomial transmission of MERS (not sure how important this is below, just be aware)
Patient 1 visited Dubai in April 2013, Patient 2 lives in France and did not
travel abroad. Both patients had underlying immunosuppressive
disorders.
Initial clinical presentation included fever, chills, and myalgia in both
patients and diarrhea in Patient 1. Respiratory symptoms rapidly became
predominant with acute respiratory failure leading to mechanical
ventilation. Both patients developed acute renal failure.
MERS-CoV was detected in the lower respiratory tract specimens with
high viral loads.
The two patients shared the same room and bathroom in the hospital for 3
days. The incubation period was estimated at 9-12 days for the second
case. No secondary transmission was documented in the hospital staff
despite the absence of specific protective measure before the diagnosis of
MERS-CoV was suspected.
Patient 1 died on May 28 due to refractory multiple organ failure.
Patient 2 recovered and was discharged from the hospital.
When do we see parainfluenza?
What group is at risk?
Vaccine available?
occurs in fall and winter, common nosocimial infection
See complications from parainfluenza in infants and young children (CROUP)
No vaccine
This virus cause lower respiratory complications in infants and young children such as Croup = subglotal , fever, hoarse voice, loss of apetite, barking cough adn stridor on inhilation
Parainfluenza
Type I and 2 parainfluenza are common causes of :
Type 3 is simular to:
Type 4 is:
1 and 2 like croup
3 simular to RSV
4 mild
Respiratory syncytial virus – key points
Where is the infection located?
What problem can it cause in infants?
When are most people infected with this?
Localized infection of respiratory tract, no systemic spread
Blockage of narrow airways of infants
Infects virtually everyone by age 2
How does Respiratory Syncytial virus cause blockage of airways in infants?
Blockage of narrow airways of infants
◊ Virus-induced CPE includes syncytia (multinucleated cells)
◊ Induction of inflammatory cytokines
ONce you are infected with RSV, will you get it again?
Natural infections do not prevent re-infection
◊ Infections throughout life, can be severe in the elderly
◊ Presents vaccine challenges
Clinical consequences of RSV in
Chilren under one:
Children:
older children/adults:
Children under 1: bronchiolitis, penumonia or both w/ fever, cough, dysnpnea and cyanosis
Children: febrile rhinitis and pharnygitis
Older: common cold
Tx of RSV in otherwise health infant:
premmaure/immunocompromised infants:
Premature:
- Otherwise healthy infant – treatment is supportive, oxygen, IV fluids, nebulized cold steam
- Premature or immunocompromised infants - aerosolized ribavirin
- Premature infants – passive immunization with anti-RSV Ig and humanized monoclonal antibodies
Metapneumovirus is simular to what disease and in what pt population?
By what age are children seropositive for Metapneumovirus and how is it identified?
Vaccine?
disease similar to RSV but in general milder, with the most severe disease seen in infants, the elderly, and immunocompromised
By 5 most kids have it, identified by RT-PCR
No vaccine available
• Two emerging respiratory viruses with high mortality
rates
• Have made the apparent jump from bats to people with
pigs as an intermediate host in Australia and Asia.
Hendra and Nipah virus
Causes a wide spectrum of disease: respiratory infection (pharyngitis), conjunctivitis (pink eye), gastrointestinal infections, hemorrhagic cystitis (inflammation of the urinary bladder)
Adenovirus
Adenovirus disease is determined by:
When do we see systemic infection of adenovirus
determined by the tissue tropism of the specific group or serotype of the virus (>50 serotypes of adenovirus)
See systemic infection in immunocompromised patients
What prevention and control is available for adenovirus?
o No adenovirus vaccine available for general public, new live
attenutated vaccine against adenovirus types 4 and 7 was
approved by the FDA in 2011 for military recruits
o Cidofovir has been used to treat s_evere adenovirus_ in
immunocompromised people
Pharyngoconjuctival fever (red eyes, sore throat adn fever in young kid)
athlete with flu like symptoms, vomitting, chills and high fever–> progressing to pneumonia
febrile respiratory illness on Naval base
What do all of these have in common?
Cuased by adenovirus
Measles virus is characterized by what symptoms?
What’s the most common cause of death in young children with measles?
cough, conjunctivitis, coryza, with otitis media, croup, pneumonia
Pneumonia
Adenovirus is in
- Which virus family?
- DNA or RNA?
- Naked or enveloped?
Adenovirdiae
DNA and Naked
Rhinovirus and enterovirus are both ______
They are DNA or RNA
Naked or Enveloped
Rhino and Entero are both Pircornavirus
They are +RNA and Naked
SARs, MERS are both Coronavirus, which is
DNA/RNA
Enveloped/Naked
Coronavirus are +RNA and Enveloped
What virus family does Influenza belong in?
DNA or RNA
Enveloped or Naked?
Inlfuenza is in Orthomyoviridae
-RNA and is Enveloped
Parainfluenza, RSV, Metapneumovirus and Measles are all in what virus famaily?
They are DNA or RNA
Naked or Enveloped
Parainfluenza/RSV/metapneumovirus/Measles
=Paramyxoviridae famiy
(-)RNA and is Enveloped