Oral Viral Infections Flashcards
What are the general characteristics of a virus?
Small- much smaller than bacteria/human cells
Simple chemical composition- proteins, phospholipids, glycoproteins, nucleic acids (changes depending on family)
No intracellular organelles- obligate intracellular parasites
DNA/RNA- can have either
What are examples of DNA/RNA viruses?
DNA virus- human herpes
RNA virus- mumps
What are the stages of replication of Herpes Simplex?
- Binding
- Entry into cytoplasm
- Release and nuclear transport
- Nuclear entry
- Gene expression- ribosomes translate viral genes into proteins
- DNA replication via viral DNA polymerase
- Packaging
- Egress via endoplasmic reticulum, golgi apparatus and plamsma membrane
What does 1/2 triangles mean?
1- Diagnosis
2- Provisional diagnosis
How is a viral sample taken?
Use viral swab- flocked
Place in molecular sample solution- extracts viral DNA/RNA
After immersion- remove swab
What is used when taking a blood sample to check for viruses?
EDTA- purple topped
-> used in serology and molecular detection of viral DNA/RNA
What information should be included in virology request form?
Pt details & clinician details (inc phone no.)
Clinical details & diagnosis
Date of onset
Patient DOB or CHI number
Specify test (do not request “viral screen”)
What is a maculo-papular rash?
Red flat area on the skin covered with bumps (macules/Papules)
Which viruses can cause a macula-papular rash?
Enterovirus
HHV6
HHV7
Measles
Rubella
*B19, CMV, EBV- require serology for detection using EDTA blood sample
What is a vesicle?
Fluid filled blister
Which viruses are associated with vesicular lesions?
HSV1
HSV2
VZV
Enterovirus
What is an ulcer?
break in bodily membrane
Which viruses are associated with causing ulcers?
HSV
Enterovirus
What specimen/test is required for detecting the cause of macula-papular rashes, vesicular lesions and ulcers?
Specimen- mouth swab
Test- RNA/DNA detection
What is serology used for?
Detect presence of antibodies against a virus?
Which viruses can be diagnosed from presence of IgM antibodies?
CMV
EB
Which viruses can be diagnosed from presence of IgG antibodies?
HSV/Varicella Zoster
Was is meant by laboratory stewardship?
Only using lab as a resource when required
-> Most diagnoses are made via history/clinical investigation
What is characteristic about the appearance of herpes viruses?
Look like a fried egg
What are the types of herpes virus?
Herpes simplex type 1
Herpes simplex type 2
Varicella zoster- chicken pox/shingles
Epstein Barr
Cytomegalovirus
HHV-6
HHV-7
HHV-8 (Kaposi’s Sarcoma Associated virus)
What are the common features of infections with HHVs?
Primary infection
Latency
Recurrent infection
What conditions can HSV1/2 cause?
Gingivo-stomatitis
Herpes labialis- cold sores
Keratoconjuctivitis
Herpetic whitlow
Bell’s palsy
Genital herpes
What are the steps in the pathogenesis of HSV?
Acute infection
Latency
Reactivation
-> Cold sores, viral shedding, cell death
What is the reservoir for HSV?
Saliva
What is the route of transmission for HSV?
Direct by close person to person contact