Oral Viral Infections

Question 1

What are the characteristics of a virus

Answer 1

• small size
• simple chemical composition
• no intracellular organelles

Question 2

Describe the structures present in a typical enveloped virus

Answer 2

• phospholipid envelope
• nucleic acid genome
• protein capsid
• spike projections

Question 3

How is genetic information stored in viruses

Answer 3

as DNA or RNA

Question 4

Describe the stages of herpes virus replication

Answer 4

1. binding
2. entry
3. release and nuclear transport
4. nuclear entry
5. gene expression
6. DNA replication
7. packaging
8. egress

Question 5

What type of virus is herpes simplex

Answer 5

DNA

Question 6

How can viruses be diagnosed

Answer 6

viral swab
blood sample (EDTA)

Question 7

What type of swab should be used for a viral swab

Answer 7

flocked

Question 8

What should the flocked swab be placed in

Answer 8

molecular sample solution

Question 9

What is required to complete a virology request form

Answer 9

• patient details
• clinician details
• clinical details and prov diagnosis
• date of onset
• patient DOB/chi
• specify test

Question 10

What is required to complete a virology request form

Answer 10

• patient details
• clinician details
• clinical details and prov diagnosis
• date of onset
• patient DOB/chi
• specify test

Question 11

What are the common pathogens that cause a maculopapular rash

Answer 11

• enterovirus
• HHV6
• HHV7
• measles
• rubella

Question 12

What are the common pathogens that cause a vesicular rash

Answer 12

• HSV1
• HSV2
• VZV
• enterovirus

Question 13

When using a mouth swab, how is viral nucleic acid detected

Answer 13

nucleic acid amplification

Question 14

How do blood tests diagnose

Answer 14

nucleic acid amplification
or antibody levels

Question 15

Which antibody response do we look for for HSV

Answer 15

IgG

Question 16

What are the 3 stages of human herpes virus

Answer 16

• primary infection
• latency
• recurrent infeciton

Question 17

What are the clinical features of type 1 and 2 HSV

Answer 17

gingivostomatitis
herpes labialis
keratoconjunctivitis
herpetic whitlow
bells palsy
genital herpes

Question 18

What can treatment for HSV be split into

Answer 18

• chemoprophylaxis
• antiviral therapy

Question 19

What is chemoprophylaxis dosage (prevention of disease)

Answer 19

ACV to prevent recurrent infection in difficult cases
200mg x 5 daily ACV

Question 20

What is the antiviral therapy tx

Answer 20

• topical therapy with ACV
• 5%
• IV therapy for severe and immunosuppressed

Question 21

What is the incubation period of varicella (chicken pox)

Answer 21

10-21 days

Question 22

What are the complications of varicella (chicken pox)

Answer 22

secondary bacterial infections (group a strep)
pneumonia
congenital, perinatal/neonetal

Question 23

What are the clinical features of zoster (shingles)

Answer 23

• vesicles appear in dermatome, representing cranial or spinal ganglia where the virus has been dormant
• the affected area may be intensely painful with associated paraesthesia

Question 24

What are the complications of shingles

Answer 24

• post herpetic neuralgia
• secondary bacterial infections
• opthalmic zoster
• ramsay hunt syndrome

Question 25

Describe the pathogenesis of varicella zoster

Answer 25

* primary infection = infection with VZ virus * latency = sensory ganglion (trigeminal) * recurrent infection = reactivation of latent virus from sensory ganglion

Question 26

What is the route of transmission of VZ

Answer 26

* durect contact, droplet or airborne spread

Question 27

What is the lab diagnosis for VZ if wanted

Answer 27

* PCR * not serum unless for HCW

Question 28

Why is VZ relevant to dentistry

Answer 28

can mimic severe toothache antiviral therapy is 800mg oral x 5 days for 7 days

Question 29

What are the different herpes viruses

Answer 29

herpes simplex varicella zoster epstein barr cytomegalovirus HHV 8 HHV 6 & 7

Question 30

What is enterovirus infection the cause of

Answer 30

hand foot and mouth disease

Question 31

What are the symptoms of hand food and mouth disease

Answer 31

fever runny nose sneezing cough skin rash, mouth blisters and body ache ** macular rash

Question 32

What is the dentally relevant enterovirus

Answer 32

coxsackie -- causes HFM

Question 33

What lab test can be used for HFM disease if uncertain diagnosis

Answer 33

oral swab for detection of enterovirus RNA

Question 34

What is the pathogenesis of measles

Answer 34

a rna virus spread through airbone transmission or direct contact with infected resp secretions

Question 35

What is the lab diagnosis of measles made from

Answer 35

mouth swab PCR

Question 36

What virus causes mumps

Answer 36

paramyxovirus RNA

Question 37

What is the incubation period of mumps

Answer 37

12-24 days

Question 38

What are the symptoms of mumps

Answer 38

* headache and fever * swelling of parotid glands

Question 39

What is aciclovir

Answer 39

an acyclic purine nucleoside

Question 40

How does aciclovir work

Answer 40

inhibits dna polymerase it tricks the herpes virus into incorporating the defective molecules into the DNA chain and so it blocks further synthesis the aciclovir is missing an OH group

Question 41

Describe in detail the mechanism of aciclovir

Answer 41

1. viral enzyomes add to phosphate group to acyclovir 2. human enzymes add two more phosphate groups, producing acyclovir triphosphate 3. during replication, acyclovir is added to the growing strand rather than GTP and this halts furhter elongation of the DNA molecule and stops viral replication

Question 42

What is aciclovir used for in dentistry

Answer 42

managing HSV (cold sores) and zoster (shingles) resistance can occur via mutation in viral thymidine kinase