Viruses Flashcards

1
Q

What are the various presentations of Parvovarius B19?

A

Pancytopaenia
Aplastic crisis in sickle cell
Hydrops foetalis

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

How does hydrops foetalis occur?

A

Causes severe anaemia due to viral suppression of fetal erythropoiesis → heart failure secondary to severe anaemia → the accumulation of fluid in fetal serous cavities (e.g. ascites, pleural and pericardial effusions)

Treatment: Intrauterine blood transfusion

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

What type of virus is hepatitis B?

A

double-stranded DNA hepadnavirus

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

How is hepatitis B spread?

A

Blood
Bodily fluids
Vertical transmission to mother

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

What are the features of hepatitis B?

A

Fevers
Jaundice
Elevated liver transaminases

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

What are the complications of Hepatitis B?

A

Chronic hepatitis
Fulminant liver failure (1%)
hepatocellular carcinoma
Glomerulonephritis
Polyarteritis nodosa
Cryoglobulinaemia

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

What are the three antigens for Hep B? And their meaning

A

Surface antigen - HBsAB
Core antigen - HBcAg
DNA polymerase associated antigen HBeAg -

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

What does presence of HBsAG mean?

A

Early acute phase - actively infectious

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

What does presence of HBsAG and Anti-HBc mean?

A

Acute disease or chronic carrier

Antibody made against core antigen

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

What does presence of anti-HBs and anti-HBc mean?

A

Antibodies to surface and core

Suggests convalescing or immune to disease

May be immune from disease or vaccination

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

What does Anti-HBc mean?

A

Recent disease - taken after HBsAG disappeared and before anti-HBs made

Patient is considered infectious

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

What does an antibody level of Anti-HBs > 100 mean?

A

Adequate response
Booster only needed in 5 years

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

What does an antibody level of Anti-HBs 10-100?

A

Suboptimal response - one additional vaccine dose should be given. If immunocompetent no further testing is required

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

What does an antibody level of Anti-HBs <10?

A

Non-responder

Give further vaccine course (i.e. 3 doses again) with testing following.

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

How is hepatitis B treated?

A

Pegylated interferon-alpha (first one available) or other pegylated interferon

enofovir, entecavir and telbivudine (a synthetic thymidine nucleoside analogue)

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

What viruses causes Orf? How is it transmitted?

A

It is caused by the parapox virus.

Transmitted for sheep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are features of off in humans?

A

Affects the hands and arms
Small, raised, red-blue papules
later may increase in size to 2-3 cm and become flat-topped and haemorrhagic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does amantidine do? And its mechanism?

A

Anti-viral / Parkinsons disease

Inhibits uncoating (M2 protein) of virus in cell.

Also releases dopamine from nerve endings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What type of virus if hepatitis D?

A

Single stranded RNA virus

It is an incomplete RNA viruses and requires hepatitis B surface antigen for transmission cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a Hepatitis D “co-infection”?

A

Co-infection: Hepatitis B and Hepatitis D infection at the same time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a Hepatitis D “superinfection”?

A

A hepatitis B surface antigen positive patient subsequently develops a hepatitis D infection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is Hepatitis D transmitted?

A

Fluids / Bodily fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the risks of a hepatitis D infection with hepatitis B?

A

fulminant hepatitis, chronic hepatitis status and cirrhosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What viruses cause genital warts?

A

HPV 6 and HPV 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Management of genital warts?
First line: Podophyllum for multiple lesions and non-keronitonised First line: Cryotherapy Solitary keritonised lesions Second line: Imiquimod
26
Which virus (and types) predispose to cervical cancer?
HPV 16, 18, 33
27
What type of virus is behind measles?
RNA paromyxovirus
28
What are the features of measles?
Prodromal phase - irritable - conjunctivitis - fever Koplik spots - typically develop before the rash - white spots ('grain of salt') on the buccal mucosa Rash - starts behind ears then to the whole body - discrete maculopapular rash becoming blotchy & confluent - desquamation that typically spares the palms and soles may occur after a week
29
Most common cause of death from measles?
Pneumonia
30
Most common complication post measles?
Otitis media
31
Complications post measles? (8)
Otitis media: the most common complication Pneumonia: the most common cause of death Encephalitis: typically occurs 1-2 weeks following the onset of the illness) Subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness Febrile convulsions Keratoconjunctivitis, corneal ulceration Increased incidence of appendicitis Myocarditis
32
An unvaccinated child comes into contact with measles, how is this best managed?
Give MMR Vaccinate antibodies develop faster than active infection Should be given within 72 hours
33
What investigation should be done for measles?
IgM antibody test
34
What is the mechanism of action of acyclovir?
Guanosine analogue require phosphorylated by tyrosine thymidine kinase to work Leads to inhibition of DNA polymerase
35
What antiviral agent should be used in HSV and VZ?
Acyclovir
36
What antiviral agent should be used in CMV?
Ganicyclovir
37
What is the mechanism of action of ganicyclovir?
Guanosine analogue requires phosphorylated by tyrosine thymidine kinase to work Leads to inhibition of DNA polymerase
38
What is the complication of acyclovir?
Crystalline nephropathy
39
What is the complication of ganicyclovir?
Myelosuppression
40
What antiviral is used in chronic hep C and RSV?
Ribavirin
41
What is the mechanism of action of ribavirin?
Guanosine analogue Inhibits IMP Interferes with the capping of viral mRNA
42
What is the complication of ribavirin?
Haemolytic anaemia
43
What antiviral agent is used in Parkinson's disease and influenza?
Amantadine
44
What is the mechanism of action of amandtadine?
Inhibits uncoating (M2 protein) of virus in cell. Also releases dopamine from nerve endings
45
When is the antiviral agent foscarnet indicated? And its mechanism of action?
If HSV or CMV not responding to acyclovir
46
What are the complications of foscarnet?
Nephrotoxicity, hypocalcaemia, hypomagnasaemia, seizures
47
What is the indication for interferon alpha?
Chronic hepatitis B & C Hairy cell leukaemia
48
What is the mechanism of action of interferon alpha?
Human glycoproteins which inhibit synthesis of mRNA
49
Side effects of interferon alpha?
Flu-like symptoms Anorexia Myelosuppression
50
What antiviral agent does not require phosphorylation to work?
Cidofovir
51
What is the indication for cidofovir?
CMV retinitis in HIV
52
What viruses can cause glandular fever?
EBV ( most common) CMV HHV-6
53
What is the classic triad of glandular fever?
Sore Throat Cervical lymphadenopathy *Anterior and posterior chain Pyrexia Please note: Tonsillitis typically give anterior china cervical lymphadenopathy - not posterior
54
What other features can be found in glandular fever?
Malaise, anorexia, headache palatal petechiae Splenomegaly - occurs in around 50% of patients and may rarely predispose to splenic rupture hepatitis, Transient rise in ALT Lymphocytosis: presence of 50% lymphocytes with at least 10% atypical lymphocytes Haemolytic anaemia secondary to cold agglutins (IgM) Maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis
55
What are the risk of varicella exposure to a pregnant mother?
Mother: Pneumonitis Foetus:features of FVS include skin scarring, eye defects (microphthalmia), limb hypoplasia, microcephaly and learning disabilities
56
Management of VZV exposure in pregnancy?
If any doubt regarding immune status - IgG Varicella should be checked If < 20 weeks gestation not immune antibody status - Give Immunoglobulin If > 20 weeks no immun antibody status - Acyclovir to be given 7-14 days AFTER exposure If rash present: >20 weeks oral aciclovir should be given if the pregnant women is ≥ 20 weeks and she presents within 24 hours of onset of the rash if the woman is < 20 weeks the aciclovir should be 'considered with caution'
57
What malignancies are associated with EBV?
Burkitt's lymphoma* Hodgkin's lymphoma nasopharyngeal carcinoma HIV-associated central nervous system lymphomas
58
What type of virus is EBV?
Herpesvirus
59
What is swine flu?
H1N1 It is a subtype of influenza A
60
What are the features of influenza?
fever greater than 38ºC myalgia lethargy headache rhinitis sore throat cough diarrhoea and vomiting
61
What is the treatment for H1N1? Mechanism?
Oseltamivir (Tamiflu) Oral medication a neuraminidase inhibitor which prevents new viral particles from being released by infected cells Zanamivir inhaled medication* also a neuraminidase inhibitor
62
What is the side effect of H1N1?
nausea, vomiting, diarrhoea and headaches
63
What is the side effect of oseltamivir? And zanamivir?
Oseltamivir: nausea, vomiting, diarrhoea and headaches Zanamivir: may induce bronchospasm in asthmatics
64
How is measles spread?
Aerosol
65
What is 5'ths disease?
Rose-red rash makes the cheeks appear bright red, hence the name ‘slapped cheek syndrome’. e virus can affect an unborn baby in the first 20 weeks of pregnancy
66
What test should be done in a pregnant mother with possible exposure to 5ths disease?
IgM IgG
67
What is the most common and serious complication of chickenpox in adults? How is this treated?
Varicella pneumonia Treated with IV acyclovir
68
What type of virus is hepatitis C?
RNA flavivirus
69
How is hepatitis transmitted?
Vertical transmission (higher risk with HIV)
70
What are the features of heptatis C?
A transient rise in serum aminotransferases / jaundice Fatigue Arthralgia
71
What is the best investigation for hepatitis C?
HCV RNA
72
If a patient has an anti-HCV what does it mean?
Previous hepatitis C infection
73
What percentage of people get chronic hepatitis C? what classifies as chronic hepatitis C?
majority (55-85%) will develop chronic hepatitis C Persistence HCV RNA for > 6 months
74
Is there a vaccine for hepatitis C?
No
75
What are the complications of chronic hepatitis C?
Rheumatological problems: - arthralgia, arthritis - eye problems: Sjogren's syndrome - cirrhosis (5-20% of those with chronic disease) Hepatocellular cancer Cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal) Porphyria cutanea tarda (PCT) Membranoproliferative glomerulonephritis
76
How is hepatitis C treated?
Aim of treatment is sustained virological response (SVR), defined as undetectable serum HCV RNA six months Combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) with or without ribavirin are used
77
What are the side effects of ribavirin?
Haemolytic anaemia Cough Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
78
What are the side effects of interferon alpha?
flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
79
What type of virus is hepatitis E? How is it spread?
RNA hepevirus Faecal oral route
80
What are the features in hepatitis E?
Severe hepatitis in a pregnant woman - think hepatitis E
81
What are the features of Japanese encephalitis?
Headache, fever, seizures and confusion. Parkinsonian features indicate basal ganglia involvement. It can also present with acute flaccid paralysis Basal ganglia inflammation
82
What is the diagnosis of Japanese encephalitis?
Diagnosis is by serology or PCR.
83
How is Lassa virus spread?
Excreta of infected African rats (Mastomys rodent) or by person-to-person spread.
84
How is the Marburg virus spread?
Risk factors for transmissions include caves/bats and primates.
85
How is hepatitis E spread?
Hepatitis E is associated with faecal-oral spread, commonly affecting shellfish and pork products.
86
What are the features of HSV 1 and HSV 2 infection?
primary infection: may present with a severe gingivostomatitis cold sores painful genital ulceration
87
How is gingivostomatitis managed? (HSV infection)?
oral aciclovir, chlorhexidine mouthwash
88
How should coldsores HSV be managed?
topical aciclovir although the evidence base for this is modest
89
How should you decide between dengue or chikungunya?
Absence of a rash makes chikungunya more likely than dengue. Both have bone pain