1 - Oral viral infections

Question 1

What are the characteristics of a virus?

Answer 1

• simple chemical composition
• no intracellular organelles
• they are obligate intracellular parasites
• genetic information carried as DNA or RNA

Question 2

Give an example of a DNA virus.

Answer 2

Human herpes viruses

Question 3

Give an example of a RNA virus.

Answer 3

Paramyxovirus (mumps)

Question 4

What are the key stages of viral replication?

Answer 4

• binding
• entry
• release and nuclear transport
• nuclear entry
• gene expression
• DNA replication
• packaging
• egress

Question 5

What is shorthand for provisional diagnosis?

Answer 5

Two triangles

Question 6

What is shorthand for diagnosis?

Answer 6

One triangle

Question 7

What is used for a viral swab?

Answer 7

• flocked swab
• placed in molecular sample solution (MSS)
• after immersion remove swab

Question 8

What is used for a blood sample?

Answer 8

• placed in purple topped tube
• EDTA solution

Question 9

What information is required on a virology request form?

Answer 9

• patient details and clinician details
• provisional diagnosis
• date of onset
• specify test required

Question 10

What viruses typically present with a maculopapular/erythematous appearance?

Answer 10

• enterovirus
• HHV6/7
• measles
• rubella

Question 11

What viruses typically present with a vesicular appearance?

Answer 11

• HSV1/2
• HZV
• enterovirus

Question 12

What viruses typically present with ulcers?

Answer 12

• HSV
• enterovirus

Question 13

Define maculopapular.

Answer 13

A mix of macules (flat discolored areas of skin) and papules (small raised bumps)

Question 14

What is used for detection of viral nucleic acid?

Answer 14

Nucleic acid amplification

Question 15

What antibody indicates a primary response?

Answer 15

IgM

Question 16

What antibody indicates a secondary response?

Answer 16

IgG

Question 17

What viruses are part of the HHV group?

Answer 17

• HSV1
• HSV2
• varicella zoster
• epstein barr
• cytomegalovirus
• HHV6
• HHV7
• HHV8 (Kaposi’s Sarcoma)

Question 18

Describe the clinical features of HSV1 and HSV2 infection.

Answer 18

• gingivo stomatitis
• herpes labialis
• keratoconjunctivitis
• herpetic whitlow
• bell’s palsy
• genital herpes

Question 19

Define herpetic whitlow.

Answer 19

A lesion (whitlow), typically on a finger or thumb, caused by the herpes simplex virus (HSV)

Question 20

What are the key stages of HSV pathogenesis?

Answer 20

• acute infection in periphery epithelial cells
• latency within nerves (retrograde transport)
• reactivation within nerves (anterograde transport)
• presents with cold sores, viral shedding, epithelial cell death

Question 21

What percentage of the population have HSV?

Answer 21

> 90%

Question 22

What is the reservoir for HSV?

Answer 22

Saliva

Question 23

What is the route of transmission of HSV?

Answer 23

Direct by close contact

Question 24

How can an immunocompromised patient present with reactivation of HSV?

Answer 24

Painful ulceration on the tongue

Question 25

What is used for chemoprophylaxis for recurrent HSV?

Answer 25

200mg x5 daily acyclovir

Question 26

What antiviral therapy is available for an acute episode?

Answer 26

Topical acyclovir 5%

Question 27

What complications are associated with varicella viral infections?

Answer 27

- secondary bacterial infections - pneumonia - congenital perinatal/neonatal

Question 28

What complications are assorted with zoster viral infections (shingles)?

Answer 28

- post herpetic neuralgia - secondary bacterial infections - ophthalmic zoster - Ramsay Hunt syndrome

Question 29

What is Ramsay Hunt syndrome?

Answer 29

Paralysis of facial nerve

Question 30

How does shingles present?

Answer 30

- vesicles present in a dermatome related to the ganglia that the virus has been dormant - area is intensely painful and may experience paraesthesia

Question 31

What antiviral therapy is available for shingles?

Answer 31

Acyclovir 800mg x5 daily for 7 days

Question 32

How does hand, foot and mouth disease present?

Answer 32

- fever, runny nose, sneezing, cough - maculopapular rash, mouth blisters, body and muscle aches

Question 33

What causes hand, foot and mouth disease?

Answer 33

Enterovirus (Coxsackie)

Question 34

How does hand, foot and mouth disease spread?

Answer 34

- nose/throat secretions - fluid from blisters/scabs - faeces

Question 35

Who typically presents with hand, foot and mouth disease?

Answer 35

<5 years

Question 36

What is the management of hand, foot and mouth disease?

Answer 36

- symptomatic relief - prevent dehydration - hand hygiene essential to prevent spread

Question 37

What are Koplicks spots?

Answer 37

Tiny white spots on buccal mucosa caused by measles infection

Question 38

What is utilised to get a lab diagnosis of measles?

Answer 38

Mouth swab and PCR

Question 39

What is utilised to get a lab diagnosis of monkeypox?

Answer 39

Mouth swab and PCR

Question 40

How does mumps present?

Answer 40

- uni or bilateral swelling of parotid glands - headache and fever

Question 41

What causes mumps?

Answer 41

Paramyxovirus family

Question 42

Which HPV is a high risk for head and neck cancer?

Answer 42

HPV-16

Question 43

How does monkeypox present?

Answer 43

- self limiting disease - rash 1-5 days post fever - blistering rash or skin lesions in mouth, on skin and genitals

Question 44

What is acyclovir?

Answer 44

- antiviral drug - acyclic purine nucleoside

Question 45

How does acyclovir work?

Answer 45

- inhibits DNA polymerase in viral DNA - mimics guanine (DNA nucleotide) and binds to the substrate, this faulty molecule can no longer replicate

Question 46

What viral enzyme interacts with acyclovir?

Answer 46

Thymidine kinase

Question 47

When is acyclovir effective?

Answer 47

- only when there is an acute infection/reactivation - acyclovir only targets virus when there is active replication - latent infections are not affected