Herpes Flashcards
Most common route of transmission
Saliva, fluids
What is their family
Herpesviridae
Basic structure
Enveloped, double stranded 150KB- QUITE SMALL
Method of infection
Lytic infection with a latent phase
HSV Primary infection
Infects epithelial cells, causing shedding and infecting nerves
HSV Reccurent infection
Virus was stored is spinal ganglion, travels down sensory neuron and causes shedding
What growth state is the virus in when symptoms are visible?
Active- multiplying in mucosal tissue
Virus responsible for primary oral herpes
HSV1 and HSV2
Symptoms of primary oral herpes
Usually Asymptomatic in children
Can lead to severe gingivostomatitis in children and hospitalisation due to pain and nil by mouth
Virus responsible or oral reactivation
Most commonly HSV1
Symptoms of oral reactivation
Usually asymptomatic
Can cause cold sores on the vermilion of lip, rarely intraoral
Reasons and characteristics for reactivation
Mostly random with non specific triggers
usually indicated with tingling and itching before active vesicles
lasts 5-10 days
Virus responsible for primary genital herpes
HSV1 or HSV2
Virus responsible for genital reactivation
HSV2
Minor complications of HSV
Secondary bacterial infections (strep/staph)
Corneal Ulcers- scarring and loss of vision
Self limiting Meningitis
What is Mollaret’s Meningitis
Recurring, asymptomatic meningits
Major complications of HSV
Herpes simplex encephalitis- usually HSV1
Neonatal Herpes Simplex
Opportunistic infection in immunocompromised.
What is Herpes simplex encephalitis?
very rare, general and focal signs of cerebral dysfunction.
Temporal lobe oedema
Prescribe aciclovir
what is herpetic whitlow
caused in finger and thump sucking, heretic lesion and digits through contact
OF OCCUPATIONAL RELEVANCE
Neonatal herpes
More probable if mother acquires primary herpes during pregnancy
If recurrent, low risk due to immunity
Diagnosis of HSV
Direct Viral Detection via PCR
Treatment of HSV
Aciclovir- oral but low bioabalibility for 5xday dose
Valaciclovir- Prodrug but expensive
Risks of Herpes Simplex encephalitis and treatment
Must be treated with intravenous Aciclovir for min 10 days. High risk of relapse so repeated lumbar puncture recommended
life cycle of Varicella Zoster
Replication in lymph nodes–> Primary viraemian–>Replication in liver/spleen–>secondary viraemia–> dissemination to skin
How is Varicella Zoster spread?
Spread via secretions and fluid from vesicles. Infection via respiratory mucosa
Progression of Varicella Zoster to Shingles
Latency period in the Dorsal ganglion of spine–> presentation in dermatomal pattern.
Characteristics of VZV primary infection
CHICKEN POX
prodrome of fever leading to centripetal distribution of lesions.
ORALLY, can present before rest of body
Progression of Chicken pox lesions
Macules (alteration of skin colour)
Papule (Solid elevated lesion)
Vesicle (elevation containing clear fluid, BLISTERS)
Pustule (Elevation containing purulent exduate)
ALL AT THE SAME TIME!
How contagious is Chicken pox?
Attack rate in household 90% with significant contact of 15 min in same room
Incubation period avg 14 days but infectious 2 DAYS PRIOR TO RASH
Opthalmic Zoster
Nasocillary branch of trigeminal nerve
Can effect both side
Post Exposure Prophlaxis of VZV
Retained for pregnant women and Immunocompromised IF significant contact occurs.
7 day delay before aciclovir treatment
Varicella and Shingle vaccine
Both live attenuated so DON’T give to immunosuppresed
Varicella in USA, boosts IgG VZV
Shingles for all over 70s
Cytomegalovirus (CMV)
relatively benign with a seroprevalence of 40%
Spread through direct secretion contact.
Primary CAN cause gladular fever
Concerns of CMV
Although generally benign, severe diseases in the compromised
Congenital infection risk at any stage, especially primary infection–>Hearing loss
Characteristics of Epstein-Barr Virus
characteristic of mononucleosis infection- general icky feeling
Young children- at most sore throat
Adolescents- glandular fever
WARNING- ONCOGENIC
Developments of EBV
latent in lympocytes
transmission via saliva and sex
ORAL HAIRY LEUKPLAKIA IN IMMUNOSUPPRESED
Roseola Infantum?
A rash presentation
Herpes 6 and 7
6 is a particular issue in transplant patients as it can cause rejection
What is Human Herpes Virus 8 associated with
Karposi’s sarcoma
Highly associated with HIV and myeloproliferative cancers
