Week 3 Day 2 Respiratory and Enteroviruses Flashcards

(56 cards)

1
Q

3 proteins on Influenza and where are they located?

A

All surface proteins.

Hemaggluttinin (HA)
Neurominidase (NA)
M2 Ion Channel

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2
Q

What is HA (Hemagglutinin) and what does it do?

A
  • Found on the surface of influenza viruses
  • Binds Sialic Acid receptors to aid in viral entry
  • Agglutinates RBCs
  • antigenic neutralizing, antibodies can bind to HA and neutralize the virus
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3
Q

What is neuraminidase aka NA?

A

A influenza surface protein that allows the replicated virus to exit a cell by by cleaving sialic/neuraminic acid.

Degrades mucin

When antibodies bind it doesn’t neutralize the virus but does slow the spread- makes sense as NA degrades mucin and is used to escape and spread mucin slows bacterial spread

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4
Q

What is an M2 Ion Channel and what does it do? Which drugs target it?

A

An influenza virus transmembrane channel

Only found in Influenza A

Target for drugs amantidine and rimantidine

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5
Q

What are the 3 human influenza sub groups and who do they infect?

A

A- humans and animals, most severe/virulent- most spread, has HA, NA and M2

B- humans only- FYI only no M2 have BM2 instead

C- humans only and not assoc with epidemics and pandemics no HA or NA and has CM2 not M2

Lack of M2 is Why most antivirals only work on A

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6
Q

For A and B flu what are the serotypes and how are the designated?

A

16 different HA types and 9 NA types

The subtypes are name after the combination of HA and NA

H1N1 H9N3 etc

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7
Q

2 types of antigenic changes?

A

Drift and Shift

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8
Q

What is antigenic drift in flu?

A

Epidemic causing-
Minor changes in surface proteins HA and NA with seasons

Happens in all subtypes A, B and C

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9
Q

What is antigenic shift in flu?

A

Pandemic causing- Total change in HA and NA or both

Happens in a cell infected with 2 strains or more strains and the proteins get mixed up

Requires animal intermediate

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10
Q

How is influenza spread?

A

Droplets, fomites and aerosol

Non-porous surfaces- 48 hrs

Clothing- 12+ hrs

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11
Q

Influenza incubation period?

A

1-4 days

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12
Q

Upper respiratory viruses?

FYI- familiar only-mark blue to skip

A

Rhino, Corona, flu, Paraflu, RSV, herpes, Adeno and Coxsackie

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13
Q

Lower respiratory viruses?

FYI familiar only-mark blue to skip

A

Flu, paraflu, RSV, adeno and metapneumo

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14
Q

Influenza symptoms?

A
Abrupt onset of:
Fever
Myalgia and malaise 
Headache
Pharyngitis 
Rhinorrhea
Cough

Lasting 5-7 days but can have a long tail of symptoms

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15
Q

When is flu infectious?

A

3-5 days after symptoms begin in most adults

Longer in kids and immune compromised

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16
Q

Why can flu be such a challenge to control?

A

Easily spread and hard to diagnose

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17
Q

Why is flu hard to diagnose?

A

Overlapping symptoms with RSV and rhinovirus

FYI only
They tend to present with more nasal congestion and respiratory problems and less fever and exhaustion where as flu is primarily fever and exhaustion with some respiratory issues

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18
Q

Major complication of flu and two types of it?

A

Pneumonia-

Primary- caused by the virus itself

Secondary- caused by an opportunistic bacteria that infects when the immune system is busy fighting the virus and

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19
Q

When Flu causes primary pneumonia how bad is it?

A

Pretty bad- 10-20% respiratory failure

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20
Q

What bacteria tend cause secondary flu pneumonia and how?

A

S. pneumoniae, S. aureus, H. influenzae

More common than primary flu pneumonia

Influenza virus degrades mucin and depresses immune system and primes body for bacterial infection

FYI
Sometimes patient starts to get better then gets worse

Immune impaired patients sometimes benefit from prophylactic antibiotics when sick with flu virus

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21
Q

Main pneumonia causing viruses by age group?

Neonates-
Infants-
Children-
Young Adults-
Old Adults

FYI be familiar

A
Neonates- RSV
Infants- RSV and Parainfluenza 
Children- RSV and Parainfluenza
Young Adults- various 
Old Adults- Influenza
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22
Q

Bacteria or viruses- which are the main cause of CAP (community acquired pneumonia)?

A

Virus

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23
Q

Another weird complication of viral infection (flu being one of the two main virus linked to it) in children?
One other thing that is linked to it?

A

Reye’s syndrome

Aspirin has been linked to it but no mechanism found

24
Q

What is Reyes Syndrome?

A

Rare life threatening-supportive care only

Happens after viral infection- mainly flu and chicken pox

Fever, rash, encephalopathy, liver failure

Possibly causes Carbamyl phosphate synthetase and ornithine transcarbamylase deficiency

25
Most common way flu is diagnosed?
Rapid PCR- greater than 95% specific and sensitive, take 20-60 minutes Some are CLIA waived- meaning they can be performed at home or in non-certified labs such as a doctors office, drugstore or pharmacy
26
Other influenza diagnostic tests not really used? | FYI- be familiar only
``` Serology HA assay- research only Viral tissue cultures- slow Direct fluorescent antibodies-only work with high viral load RT PCR-take time Rapid antigen- not sensitive ```
27
What is the best way to prevent flu?
Hygiene and highly effective 70-90% vaccine
28
Two types of antiviral flu treatments?
Neuraminidase Inhibitors and M2 Blockers
29
More on NA inhibitors?
Work for A and B Can uses prophylactically Work best is used early- difficult Zanamivir (inhaled) and Oseltamivir/Tamaflu (oral)
30
More on M2 blockers?
Work on A only Problems with resistance Not recommended in US Amantidine and Rimantidine
31
Types of flu vaccines and purpose of them?
Inactivated and live attenuated Used to Prevent severe complication not infection
32
Viruses that cause upper respiratory viruses that she wants us memorize?
``` Rhinovirus Coronavirus RSV/Respiratory Syncytial Virus Adenovirus Coxsackievirus (a specific enterovirus) ```
33
2 of the Viruses that cause upper respiratory viruses that she wants us memorize that ALSO cause LOWER respiratory infections? In red/Memorize
RSV and | Adenovirus
34
More about rhinovirus? | 5 points
Greater than 150 different antigenic types- many circulate simultaneously Kids get 5-12 a yr No vax and no proven effective tx Relatively Stable to disinfectants! Emerging cause of lower respiratory tract disease. Mutations?
35
How is adenovirus transmitted and treated?
Droplets and fecal oral No specific tx supportive care
36
What does adenovirus cause aka symptoms?
Pharyngitis, pneumonia, conjunctivitis, gastroenteritis, acute respiratory diseases Connections between subtypes and syndrome types - 3 and 7 swimming pools, Type 4 military recruits
37
Is there a vaccine for adenovirus?
Yes only for one subtype 4 given to military people only
38
Couple points about RSV infections?
No vaccine Can be severe in infants and elderly
39
What type of well known virus causes 5-30% of common colds and how many serotypes of it are there?
Coronaviruses Unknown number of serotypes
40
3 major corona virus caused epidemic/pandemics?
SARS - 2003 MERS - 2013. Zoonotic SARS Cov-2 aka Covid 19
41
What part of the body do entroviruses infect and are humans the only natural host?
Human are only host and they can infect both the GI and Respiratory tracts Can cause meningitis and muscle infections (coxsackievirus) Coxsackievirus and polio are famous ones Also Coxsackievirus combined with enterovirus A-71 (Hand Foot and Mouth)
42
What in our innate immune system recognizes enteroviruses to try to fight them off and what is the main immune responses are triggered?
TLR3’s are the most important PRR for enteroviruses Responses via Type 1 interferons and IgA
43
How acid-stable are enteroviruses?
Very- they can pass though our entire GI tract and emerge immediately infectious
44
3 major groups who are at risk from enteroviruses and what time of year do most case occur?
Most cases occur in the summer and fall. Neonates Antibody deficient patients Stem cell transplant patients
45
What do Neonates get from enteroviruses?
Fever and sleepiness due to Sepsis and multi-organ failure 10% have seizures
46
What do Antibody-Deficient patient get from enteroviruses?
Persistent CNS infections
47
What do Stem Cell Transplant patients get from enteroviruses?
Multi- Organ disease
48
An enterovirus that causes upper Respiratory tract infections mostly in children?
Coxsackievirus causes Herpangina
49
What is Herpangina and what are the symptoms?
An upper respiratory tract infection of Coxsachievirus A that has only Oral symptoms and no systemic symptoms Ulcers/erythematous papules or small vesicles with erythematous base that are on the posterior palate, pharynx, tonsils and sometimes outside the mouth Often accompanied by high fever Self limiting
50
What is a common symptom caused by different enterovirus serotypes infections?
Rashes | They are often a result of the secondary viremia which passes the infection to other tissue aka the skin
51
Famous enterovirus caused Rash syndrome and the symptoms?
Hand Foot and Mouth Disease Caused by Coxsackievirus and Enterovirus A-71 Sores in mouth and rash on hands and feet
52
Two infections of muscle caused by Coxsackievirus and the symptoms?
Myositis- infected muscles both striated and cardiac- muscles sore to touch and difficulty walking due to pain Myocarditis and pericarditis- disfunction of heart and cardiac failure
53
What would the cerebrospinal fluid look like if the meningitis was caused by an enterovirus?
WBC count- Med high ++ WBC type- Lymphs Glucose- normal Protein- Med high ++
54
What is the most common cause of viral meningitis/encephalitis and how does it present?
``` Enterovirus- Acute onset fever, Headache, Meningismus (stiff neck), Photophobia, Emesis (🤮), Maybe rash and other typical enterovirus symptoms ```
55
What diseases can Enterovirus serotype A-71 cause?
``` Hand Foot and Mouth Disease (HFMD), Severe neurological (meningitis) and cardiovascular disease (Myocarditis) ```
56
Famous enterovirus that has been largely eradicated due to a vaccine introduced in the 1950s and what type of vaccine is given in the US?
Polio | Inactivated virus vax is given in US