Viral

Question 1

Mechanism of acyclovir?

Answer 1

nucleoside analogue which inhibits viral DNA polymerase

Question 2

Indications for acyclovir?

Answer 2

HSV type 1 and type 2
VSV
occasional EBV

Question 3

Precautions in prescribing acyclovir?

Answer 3

Reduce dose in renal impariment as crystalises in the tubules
Rare - neurologic toxicity

Question 4

Mechanism of gancylcovir?

Answer 4

nucleoside analogue which inhibits viral DNA polymerase

Question 5

Indications for Gancyclovir?

Answer 5

CMV

Question 6

Side effects of gancyclovir?

Answer 6

Resistance can develop through target site mutations (ie. DNA polymerase)
Myelosuppression
Renal impairment

Question 7

Mechanism of action of Ostelmavir?

Answer 7

Neramindase inhibitor

- prevents budding of virus from host cell

Question 8

Indications for Ostelmavir?

Answer 8

Influenza A and B

Question 9

Side effects of Foscarnet?

Answer 9

Renal insufficiency

Electrolyte wasting - low K, MG, phos, Ca

Question 10

Clinical features of CMV infection?

Answer 10

Prolonged fever, night sweats, malaise, anorexia, fatigue, arthralgias
Deranged LFTs, leucopenia, thrombocytopenia, and atypical lymphocytes
Lung involvement: SOB, hypoxia, non productive cough with bilateral interstitial infiltrates that begin in the periphery of lower lobes and spread upwards
GI involvement: oesophageal ulcers, stomach, small intestine or colon, hepatitis (particularly after liver transplant)

Question 11

What complications of CMV occur more frequently in HIV patients?

Answer 11

Meningioencephalitis and retinitis particularly in HIV patients

Question 12

Highest risk time period for CMV after transplant??

Answer 12

1-4 months following transplant

Question 13

Possible treatment options for CMV?

Answer 13

Valgancyclovir
Gancyclovir
Foscarnet
Cidofovir

Question 14

Complications of EBV in the immunocompromised?

Answer 14

EBV lymphoproliferative disorder

Oral hairy leukoplakia in HIV patients

Question 15

Manifestations of HHV-6 in immunocompromised?

Answer 15

Cytopenias
Limbic encephalitis
Hepatitis
Pneumonitis

Question 16

Manifestations of HHV-8 in immunocompromised?

Answer 16

Kaposis sarcoma
Castlemans disease
Primary effusion lymphoma

Question 17

How does ebola virus enter the cell?

Answer 17

glycoprotein 1 and 2 on the surface of virus bind to cell surface markers

Question 18

How does MERs-Cov enter the cell?

Answer 18

Enters via DPP-4 on non ciliated bronchial cells

Question 19

What type of virus is the ebola virus?

Answer 19

Filovirus

Question 20

What type of virus is dengue?

Answer 20

Flavivirus

Question 21

What are the phases of infection with dengue?

Answer 21

inital: fever, retroorbital pain, rash, arthralgia, headache, back pain
defeverescence: occurs around 3-7 days (at risk for getting critical disease - haemorrhagic fever/shock syndrome)
recrudescence: rash, skin desquamation and fever
recovery

Question 22

Complications of Dengue?

Answer 22

Dengue shock syndrome = haemorrhagic dengue + shock
Increased vascular permeability
Marked thrombocytopenia
Torniquet test - petichiae

Question 23

Diagnosis of dengue?

Answer 23

serology - arbovirus Igm/IgG
NS1 antigen can be tested early and is specific
Bloods - plts less than 100 and raised LFts = severe disease

Question 24

Vector of dengue?

Answer 24

Aedes aegyptii

Question 25

Countries that have dengue?

Answer 25

Across equatorial band | - occurs in northern queensland

Question 26

What is the incubation period?

Answer 26

3-10 days | Greater then 14 days - excludes diagnosis

Question 27

Tests for EBV?

Answer 27

``` Blood film - atypical lymphocytes Heterophile antibodies (aka Paul Bunnell/Monospot - not sensitive or specific EBV serology more specific - VCA IgM/IgG and EBNA - last for life ```

Question 28

Causes of infectious mono

Answer 28

EBV most common - 90% CMV Toxoplasmosis HIV

Question 29

What infections do you get with HSV-1?

Answer 29

Oral ulcers | Meningoencephalitis

Question 30

What infections do you get with HSV-2?

Answer 30

Genital ulcers - painful lesions | Meningitis

Question 31

What does antigen shift mean (in context of influenza)

Answer 31

Major genetic reassortment of surface proteins (Haemagglutinin & Neuraminidase) Cause pandemics as population has not previously been exposed

Question 32

What does antigenic drift mean (in context of influenza)

Answer 32

Point mutations in surface proteins resulting in small change Cause epidemics/local outbreak as population has seen part of virus before

Question 33

Complications of influenza

Answer 33

Pneumonia - viral and secondary bacterial Myositis Rhabdomyelitis CNS involvement - transverse myelitis, GBS, aseptic meningitis Myocarditis/pericarditis

Question 34

Groups at high risk for severe influenza

Answer 34

``` Children 65 Chronic illness Pregnant Obesity Immunocompromised - particularly IgG2 Asthma ```

Question 35

5 types of illness from Parvovirus B19

Answer 35

``` Slapped cheek - erythema infectiosum Polyarthropathy syndrome Transient aplastic crisis Fetal infection Chronic infection in immunosuppressed host ```