Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Virology 2 > Questions from S 2 > Flashcards

Questions from S 2 Flashcards

1
Q

What are other names for slapped cheek?

A

Parvo B19

5th disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 months old child with hepatitis

HHV6 detected as the cause

What is unique about this infection?

A

Most people have had infection previously, so would expect mother to transfer maternal antibody. So baby should be protected for 6-12 months. And acquire primary infection at aged 1-3

However, given evidence of infection early in life, this might suggest that this baby has chromosomally integrated HHV6. This was transferred by mother/father in the gametes

HHV6 inserts near telomeres in sperm/ egg, so 50% chance of passing on to child

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2 month old child with hepatitis

HHv6 detected as the cause

How to test for potential chromosomally integrated HHV6?

A

Send EDTA whole blood and clot sample for HHV6 pcr

EDTA whole blood - has all cells, including cells with chromosomes, so will have high HHV6 viral load

Clot - serum and blood cells separate out. Will have significantly lower viral load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is difference between blood plasma and blood serum?

A
  • Serum sample has a clotting agent (clot sample). Fibrinogen clots together, and binds to RBCs removing them. This leaves a liquid portion - called the serum.
    Serum is plasma minus RBC and fibrinogen
    Useful for antibody tests as proteins left in the serum
  • Whole blood (EDTA sample)
    Starting with whole blood, if an anticoagulant is added immediately after collection, then coagulation is prevented and all components are kept in suspension. If you just leave this blood sample alone without mixing, then all the components will settle out. The heavier cells will sink to the bottom. This results in a clear liquid at the top. This clear upper layer is plasma which is essentially all the components of blood minus the cells. Under centrifugation, a layer of white cells called the buffy coat forms between the plasma and red blood cells. Plasma retains fibrinogen.
    Useful for PCR tests
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

You are running a haematology clinic with bone marrow transplant patients

Specify virological investigations for these cases

52 year old with vesicular rash extended from legs up to back

official question

A

Swab/ scraping/ scab

VZV
HSV
Entero
Mpox (Orthopox)

Other Orthopox - Vaccinia if has smallpox vaccine, Cowpox
Parapox - Orf

Electron microscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

You are running a haematology clinic with bone marrow transplant patients

Specify virological investigations for these cases

72 year old 4 months post-bone marrow transplant. ALT 74

official question

A

serum/ plasma
HBsAg ELISA

EDTA
HCV RNA RT PCR
CMV PCR

Other
HAV RNA PCR
HEV RNA PCR
HSV PCR
VZV PCR
Adenovirus PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the case definition of Mpox?

official question

A

Possible case

a febrile prodrome compatible with mpox infection, where there is known prior contact with a confirmed case in the 21 days before symptom onset

an illness where the clinician has a suspicion of mpox, such as unexplained lesions, including but not limited to:
genital, ano-genital or oral lesion(s) – for example, ulcers, nodules proctitis – for example anorectal pain, bleeding

Febrile prodrome consists of fever ≥ 38°C, chills, headache, exhaustion, muscle aches (myalgia), joint pain (arthralgia), backache, and swollen lymph nodes (lymphadenopathy).

Probable case
A probable case is defined as anyone with an unexplained rash or lesion(s) on any part of their body (including genital/perianal, oral), or proctitis (for example anorectal pain, bleeding) and who:

has an epidemiological link to a confirmed, probable or highly probable case of mpox in the 21 days before symptom onset
or

identifies as a gay, bisexual or other man who has sex with men (GBMSM)
or

has had one or more new sexual partners in the 21 days before symptom onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the mechanism of action of tecovirimat?

official question

A

P37 inhibitor

Tecovirimat inhibits the function of a major envelope protein

so virus cannot leave infected cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the mechanism of action of cidofovir?

official question

A

Inhibits viral DNA polymerase

Cidofovir is a monophosphate nucleotide analog(cytosine).

After undergoing cellular phosphorylation to its diphosphate form, it competitively inhibits the incorporation of deoxycytidine triphosphate (dCTP) into viral DNA by viral DNA polymerase. Incorporation of the drug disrupts further chain elongation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

You are running a haematology clinic with bone marrow transplant patients

Specify virological investigations for these cases

54 year old with haematuria

official question

A

Blood -
BK virus
Adenovirus

Urine
BK virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

You are running a haematology clinic with bone marrow transplant patients

2 year old with watery diarrhoea

official question

A

Stool -
Adenovirus
Rotavirus
Enterovirus
Parechovirus
Astrovirus
Calicivirus - Norovirus/Sapovirus

Blood- CMV

OCP - giardia, Crytosporidium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Different treatment of HSV infection.

What is treatment of HSV infection?

A

400mg 5x for simple infection

5mg/ kg TDS for severe infection or in immunocompromised

10mg/kg TDS for encephalitis

(

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How long does HIV survive in environment?

A

99% decay by 24 hours

likely survival time is a lot lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are methods to disinfect surfaces with HIV?

A

heat 60degC for 30 mins

standard germicide - 70% alcohol or 10% beach

pH extreme <6 or >10 for 10 mins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the link between HIV and other STIs?

A

Other STIs greatly increase the probably of HIV, and in fact help with increasing transmission

e.g HSV causes ulcers which can help transmission. HSV infection also recruits inflammatory which cells, which provides more CD4 cells for HIV to infect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

From exposure to virus, what is the general path of viral spread in the body?

A

APC present to resting CD4 cells which become activated

CD4 cells move to lymph nodes and establish reservoir. Particularly early is the destruction of GALT

CD4 cells become depleted, and this stimulates production from bone marrow. Unfortunately this just creates a new population of susceptible cells

CD8 t-cells kill infected CD4 cells

CD4 cells produce some antibodies to fight HIV virus, and so viral load reduces quickly after first couple of weeks

17
Q

In the asymptomatic phase of HIV infection, what is meant by the virologic set point

A

by 3-4 months viremia reduced to low levels

Degree of viremia at this point is called virologic set point

This is a predictor of disease progression

18
Q

What is the HIV nadir?

A

CD4 nadir is lowest point of CD4 count

19
Q

55 year old male NHL – starting R-CHOP

Clotted blood available
HBsAg neg
Anti-HBc pos
HBV DNA neg

Explain this serological profile

official question

A

HBsAg neg
Anti-HBc pos
HBV DA neg

Explain profile –
blood products - haematology patient
past infection

20
Q

55 year old male NHL – starting R-CHOP

Clotted blood available
HBsAg neg
Anti-HBc pos
HBV DNA neg

What actions would you take?

official question

A

Rituximab high risk drug

Start tenofovir 245mg OD/ entecavir 1g OD a week before R-CHOP

Follow up HBV DNA ever 2-3 months

Monitor ALT

21
Q

19 year old with lymphadenopathy and deranged LFTs
Clotted blood sample available

CMV IgM pos, IgG pos, aviditiy 0.8

EBV vca IgM pos, IgG pos, EBNA neg

Explain the serological profiles

Official question

A

Would want to know if patient is immunosuppressed or has had recent blood products before interpreting

CMV IgM pos, IgG pos, aviditiy 0.8

EBV vca IgM pos, IgG pos, EBNA neg

Explain profiles –

CMV –
- high avidity >0.6 indicates distant past infection
- IgM could be cross-reactive finding given EBV strongly pos
- could also be reactivation, or a re-infection, but less likely

EBV -
- consistent with recent acute primary infection

22
Q

19 year old with lymphadenopathy and deranged LFTs
Clotted blood sample available

CMV IgM pos, IgG pos, aviditiy 0.8
EBV vca IgM pos, IgG pos, EBNA neg

What other tests would you do?

Official question

A

Rhematoid factor

HIV 1/2 Ag/Ab test - lymphadenopathy/ mononucelosis like illness

EBV/ CMV viral load

23
Q

What are the CMV avidity cuttoffs?

A

<0.4 low

> 0.6 high

intetween - indeterminate

24
Q

Mother with HIV decides to bottle feed

What drug would you give to supress lactation?

official question

A

Cabergoline

Cabergoline is a long-acting dopamine receptor agonist with a high affinity for D2 receptors. Inhibits prolactin secretion by the anterior pituitary

1mg on day of delivery
250 micrograms every 12 hours for 2 days after delivery

25
Q

3 year old with hereditary spherocytosis. Aplastic crisis
Parvo IgM/ IgG neg
CMV IgM neg, IgG pos
EBV vca IgM pos, IgG pos, EBNA neg
RF pos

How would you interpret these results?

official question

A

Parvo IgM/ IgG neg
CMV IgM neg, IgG pos
EBV vca IgM pos, IgG pos, EBNA neg
RF pos

Interpretation:
- Parvo neg - but can be not detectable early infection, or immunocompromised

  • CMV – past infection most likely
  • EBV – RF could cause IgM reactivity. Or could be late primary, or reactivation
  • note all results may be misleading if patient has received blood products
26
Q

3 year old with hereditary spherocytosis. Aplastic crisis
Parvo IgM/ IgG neg
CMV IgM neg, IgG pos
EBV vca IgM pos, IgG pos, EBNA neg
RF pos

What tests would you do next?

official question

A

EDTA sample for:
Parvo DNA PCR
EBV DNA PCR
CMV DNA PCR

Consider follow up serology in a few weeks

27
Q

Respiratory 24-plex assay

Multiple targets - viruses and bacteria

Why does our assay have both SARS-CoV-2 ORF1 and ORF8 targets?

A

Viruses at high risk of mutation

Minimum is to have 2 targets for SARS-CoV-2

This increases your positive predictive value when you have both targets present.

This increases your negative predictive value when both targets are absent

Virology 2 (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions