Oral Viral Infections Flashcards
What must be included on a virology request form?
lab diagnosis
- patient details and clinicia details (inc. phone no.)
- clinical details and provisional diagnosis
- date of onset
- patient date of birth or CHI number
- specify test
What are the clinical features of herpes simplex types 1 & 2?
- gingivo stomatitis
- herpes labialis
- keratoconjunctivitis
- herpetic whitlow
- bell’s palsy
- genital herpes
What is the pathogenesis of herpes simplex?
- acute infection
- latency (retrograde transport)
- reactivation (anterograde transport)
- cold sores, viral shedding, epithelial cell death
How can herpes simplex types 1 & 2 be diagnosed?
- history and clinical appearance
- vesiscle/ulcer fluid - swab and molecular sample media for PCR
What is the management of herpes simplex infections?
Local measures
Advise the patient to:
* avoid dehydration and alter their diet (include soft food and adequate fluids)
* use analgesics
* use antimicrobial mouthwash
Chlorhexidine mouthwash, 0.2%.
Send: 300ml
Label: Rinse mouth for 1min with 10ml 2x daily
or
Hydrogen peroxide mouthwas, 6%.
Send: 300ml
Label: Rinse mouth for 2 mins with 15ml diluted in half a tumbler of warm water 3x daily
For immunocompromised patients and severe infections in non-immunocompromised patients:
Aciclover tablets, 200mg
Send: 25 tablets
Label: 1 tablet 5x daily for 5 days
For treatment of herpes labialis, administer at the prodromal stage of a herpes labialis lesion:
Aciclover cream, 5%
Send: 2g
Label: Apply to lesion every 4hrs 5x daily for 5 days
SDCEP
What are the complications of Varicella
chickenpox
- secondary bacterial infections
- pneumonia
- congenital, perinatal/neonatal
What is varicella also known as?
chickenpox
What is the incubation period for varicella (chickenpox)
10-21 days
What are the signs and symptoms for zoster?
shingles
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.
What is shingles also known as?
zoster
What are the complications of zoster (shingles)?
- post herpetic neuralgia
- secondary bacterial infections
- ophtalmic zoster
- ramsay hunt syndrome
What is the pathogenesis for varicella zoster?
- primary infection with varicella zoster virus
- latency (sensory ganglion trigeminal)
- recurrent infection (reactivation of latent virus from sensory ganglion)
How can varicella zoster be diagnosed?
- history and clinical appearance
- vesicle/ulcer fluid - swab and molecular sample media for PCR
What test can be done for a healthcare worker that has been exposed to chickenpox/varicella?
serum for IgG test
How can chickenpox/varicella be prevented?
The chickenpox vaccine is not part of the routine childhood vaccination schedule in UK.
It is only offered on the NHS to people who are in close contact with someone who’s particularly vulnerable to chickenpox or its complications.
What is the management of varicella-zoster infections?
Aciclovir (systemic antiviral) is the drug of choice to reduce the incidence of post-herpetic neuralgia and viral shedding.
Start treatment at diagnosis or within 72hrs of the onset of the rash.
Refer all patients with herpes zoster to a specialist or their GMP.
Aciclovir tablets, 800mg (shingles treatment pack)
Send: 35 tablets
Label: 1 tablet 5x daily for 7 days
(not licensed for children!)
SDCEP
What alternative antiviral drugs are available for the management of varicella-zoster infections?
not aciclovir
- valaciclovir
- famciclovir
SDCEP
How can zoster infections be prevented?
Zostavax vaccine (live attenuated virus) is scheduled for all people aged 70 and above.
What are the signs and symptoms of enterovirus infection?
hand, foot and mouth disease
fever
runny nose
sneezing
cough
skin rash
mouth blisters
body and muscle aches
What are enteroviruses?
A large group of viruses including polio virus.
A dental relevant non-polio enterovirus is coxsackie virus.
How can enterovirus infection HFMD be diagnosed?
- history and clinical appearance
- oral swab for detection of enterovirus RNA is uncertain diagnosis
What is the management for HFMD?
hand, foot and mouth disease
no specific medical treatment available.
- relieve symptoms and prevent dehydration
- hand hygiene important in limiting spread
What are the signs and symptoms of measles?
7-14 days after exposure:
* high fever
* cough
* runny nose
* conjunctivitis
2-3 days later:
* Koplik spots (tiny white spots inside the mouth)
3-5 days later:
* rash begins on face and spreads downwards
What are the complications of measles?
- pneumonia
- diarrheoa
- hearing loss
- brain swelling
- death
How can measles be diagnosed?
PCR from mouth swabs
What is the management of measles?
no specific treatment available
vaccine preventable
What is parotitis also known as?
mumps
What is the incubation period for mumps?
parotitis
12-24 days
What are the signs and symptoms of mumps?
parotitis
- headache and fever
- swelling of the parotid glands (uni or bilateral)
What causes mumps?
parotitis
paramyxovirus (RNA)
highly transmissable by direct contact with saliva/fomites or aerosol
How can mumps be diagnosed?
parotitis
- oral swab for RNA detection
- oral fluid samples for oral fluid IgM antibody tests or PCR
What is the management for mumps?
parotitis
treatment is aimed at relieving symptoms.
routine vaccinnation can prevent symptoms.
UK children have measles mumps rubella (MMR) vaccine as part of the routine childhood immunisation schedule.
What is monkeypox?
A self-limiting disease.
Symptoms begin 5-21 days after exposure.
Rash begins 1-5 days post-fever.
Blistering rash or skin lesions on the face and genital area.
Can be confused with herpes simplex virus, chickenpox or syphilis.
What is the pathogenesis of monkeypox?
- enveloped DNA virus
- transmitted through close contact with an infected person or animal, or with material contaminated with the virus
Zoonotic sources: rope squirrels, tree squirrels, Gambian pouched rats, dormice and non-human primates.
How can monkeypox be diagnosed?
PCR for viral DNA from swabs
How can monkeypox be prevented?
vaccine:
modified vaccinia ankara (MVA)
an attenuated (weakened) strain of the vaccinia virus (does not contain smallpox virus and cannot spread or cause smallpox).
minimum PPE for staff working with possible cases of monkeypox:
fluid repellent surgical facemasks, gowns, gloves and eye protection
What is aciclovir?
Acyclic purine nucleoside.
Aciclovir inhibits DNA polymerase.
How does aciclovir work?
acyclic purine nucleoside
- viral enzyme (thymidine kinase) has a higher affinity for aciclovir and adds a phosphate group to it.
- human enzymes add two more phosphate groups, producing aciclovir triphosphate
- aciclovir triphosphate is a better substrate for viral than for host cell DNA polymerase and so causes preferential termination of viral DNA synthesis
