Oral Viral Infections

Question 1

What size is the human herpes virus?

Answer 1

0.1-0.2um

Question 2

What size is bacteria?

Answer 2

1-3um

Question 3

What size are RBCs?

Answer 3

7-8um

Question 4

What are some characteristics of viruses?

Answer 4

• small size
• simple chemical composition
• no intracellular organelles
• genetic information as DNA or RNA

Question 5

What are the key stages of replication of the Herpes Simplex virus?

Answer 5

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

Question 6

what is the first principle of laboratory diagnosis?

Answer 6

good history & examination

Question 7

What are the principles of a lab diagnosis?

Answer 7

• good history & exam
• give provisional diagnosis
• diagnosis from swab

Question 8

What is an example of a method of specimen retrieval?

Answer 8

viral swab

Question 9

How is a viral swab taken?

Answer 9

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

Question 10

How are blood samples sent for viral inspection?

Answer 10

• EDTA

Question 11

What should be included on a virology request form?

Answer 11

• Pt details & clinician details (include phone number)
• clinical details & provisional diagnosis
• date of onset
• patient DOB or CHI number
• specify test you require

Question 12

How does Herpex Simplex virus look under the SEM microscope?

Answer 12

fried egg appearance

Question 13

What are some common features of the human herpes virus?

Answer 13

• primary infection –> latency –> secondary infection

Question 14

What are the clinical features of herpes simples type 1 & 2?

Answer 14

• gingivo stomatitis
• herpes labialis
• keratoconjunctivitis
• herpectic whitlow
• Bell’s palsy
• genital herpes

Question 15

how common is the herpes simplex virus?

Answer 15

around >90% of population have it

Question 16

What is the reservoir for the herpes simplex virus?

Answer 16

saliva

Question 17

What is the route of transmission of the herpes simplex virus?

Answer 17

direct by close person to person contact

Question 18

When is herpes most commonly occuring?

Answer 18

childhood

Question 19

How is herpes simplex treated to prevent recurrent infection in difficult cases?

Answer 19

ACV 200mg x 5 daily (chemoprophylaxis)

Question 20

How is antiviral therapy used to treat herpes simplex infections?

Answer 20

• topical therapy with ACV (aciclovir cream 5%)
• IV therapy for severe & immunosuppressed

Question 21

What is the incubation period for varicella (chickenpox)?

Answer 21

10-21 days

Question 22

what are some complications associated with varicella (chickenpox) infections?

Answer 22

• secondary bacterial infections
• pneumonia
• congenital, perinatal/neonatal problems

Question 23

What are the clinical features of the zoster (shingles) virus?

Answer 23

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

Question 24

What are some complications of the zoster (shingles) virus?

Answer 24

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

Question 25

What are the steps of infection of the vericella - zoster virus?

Answer 25

1. primary infection = infection with varicella zoster virus 2. remains latent in the sensory ganglion (trigeminal) 3. reactivation of latent virus from sensory ganglion

Question 26

What is the route of transmission of the varicella-zoster virus?

Answer 26

direct contact - droplet or airborne spread

Question 27

In which population is the varicella virus most common?

Answer 27

children

Question 28

In which population is the zoster virus most common?

Answer 28

elderly & immunocompromised

Question 29

How is shingles treated?

Answer 29

Aciclover: 800mg Oral x 5 daily for 7 days

Question 30

How can zoster infection be prevented?

Answer 30

Vaccine - Zostavax

Question 31

When is Zostavax given?

Answer 31

All people aged 70 + years old

Question 31

What type of vaccine is Zostavax?

Answer 31

live attenuated virus

Question 32

What disease does enterovirus infection cause?

Answer 32

hand, food & mouth disease

Question 33

What are the symptoms of hand foot and mouth disease?

Answer 33

- fever - runny nose - sneezing & cough - skin rash - mouth blisters - body & muscle aches

Question 34

What is the dentally relevant non-polio enterovirus?

Answer 34

Coxsackie virus

Question 35

How is hand, foot & mouth disease treated?

Answer 35

No active medical treatment - relieve symptoms - prevent dehydration

Question 36

What are the signs & symptoms of measles 7-14 days after exposure?

Answer 36

- high fever - cough - runny nose - conjunctivitis

Question 37

How does measles present clinically?

Answer 37

- begins with tiny white spots inside mouth (Koplik spots) - rash begins on face & spreads downwards

Question 38

What complications can arise from measles infection?

Answer 38

- pneumonia - diarrhoea - hearing loss - brain swelling - death (extreme)

Question 39

How does measles spread?

Answer 39

RNA virus spreads via airborne transmission OR direct contact with infected respiratory secretions

Question 40

What is the incubation period of mumps?

Answer 40

12-24 days

Question 41

What are the symptoms of mumps?

Answer 41

- headache - fever - swelling of parotid gland

Question 42

How is mumps transmitted?

Answer 42

direct contact with saliva/fomites or aerosol

Question 43

What type of human papilloma virus is a risk factor for development of head & neck cancer?

Answer 43

HPV-16

Question 44

What is aciclovir?

Answer 44

acrylic purine nucleoside

Question 45

How does aciclovir work?

Answer 45

1. viral enzymes add a phosphate group to aciclovir 2. human enzymes add 2 more phosphate groups, producing aciclovir triphosphate 3. during viral DNA replication, acicloir is added to growing strand rather than GTP & this halts viral replication

Question 46

What is aciclovir used for?

Answer 46

Treatment of: - herpes simplex (cold sores) - zoster (shingles) infections