Herpes Viruses
·
All Herpes viruses exhibit
latency
·
Manifestations: systemic (fever,
sore throat), gingivostomatitis (ulcers with yellow slough – cold sores),
meningitis (uncommon, self-limiting), encephalitis (fever, fits, headache,
dysphagia, hemiparesis – do PCR on CSF sample – refer urgently)
·
Incubation: 2 – 25 days. Chronic
infection is due to the virus remaining in the sensory nerve ganglia.
Infectious period indeterminate ® contact isolation
·
Symptoms:
o Blisters which become shallow painful ulcers, often preceded by itching
or tingling
o First episode may be accompanied by flu like illness, tender inguinal
nodes and dysuria
o Recurrences can be brought on by stress, fatigue, depression,
immunosuppression and concurrent illness. Recurrences usually less severe and
become less frequent
·
Diagnosis: clinical suspicion.
Swab the base of an unroofed ulcer and refrigerate in viral medium. This will
be painful. Culture negative doesn‟t exclude HSV as timing and collection
technique important.
·
Serology possible, but not
routinely used
·
Pathogenesis. There are two antigenic types of Herpes
Simplex Virus:
o Type 1 is associated with lesions on the face and fingers, and sometimes
genital lesions. Treat with zovirax (topical cream). Prevalence: 70% of
population
o Type 2 is associated almost entirely with genital infections, and
affects the genitalia, vagina, and cervix and may predispose to cervical
dysplasia. 10% of oral lesions caused by type 2. Prevalence: 10 – 15% of
population (depends on population – more in high risk)
·
Infection of fingers or thumb
leads to a whitlow (vesicles coalesce)
·
Can infect eczematous skin ® eczema
herpeticum
·
Children:
o HSV1 the most common type in children.
o Primary infection in childhood leads to gingivostomatitis – may lead to
dehydration as child won‟t drink. May need NG tube
o Dribbling can ® perioral spread
o Auto-inoculation can ® conjunctivitis, genital lesions, skin infection with eczema (eczema
herpeticum) can be severe
o If neonate or immunocompromised can be life-threatening
o Treatment: Oral analgesics (eg lignocaine) and Paracetamol. Acyclovir
·
Description:
o Painful, recurrent condition.
o Male – anus or penis – small grouped vesicles and papules + pain, fever,
dysuria. Dysuria may be severe enough to cause urinary retention
o 20% may have it, but 20% are asymptomatic and 60% mild or unrecognised
·
40% caused by type 1, 60% by type
2
·
Transmission: spread through
skin-to-skin contact, usually when skin is broken or lesions present, but
asymptomatic viral shedding a possible route of transmission. Neonatal
transmission is rare (1 in 10,000 live births), but carries risk of ophthalmic
infection Þ caesarean section indicated if active blisters at delivery
·
Prevention of genital herpes: Condoms
with new partner (although doesn‟t eliminate risk). Avoid sex during an
outbreak
·
Can have extra genital lesions on
thighs and buttocks. Can ® radiculoneuropathy ® urinary retention/constipation
·
Treatment of Genital Herpes (type
1 or 2):
o Acute: Acyclovir 200 mg 5 times daily for 5 days. Topical creams not effective. Symptomatic
o treatment: salt bathing, local anaesthetic creams, oral analgesia, oral fluids. Counselling and follow-up important – written information for patients and partners, Herpes Helpline (0508 11 12 13)
o Suppressive Therapy: Where frequent outbreaks or psychological
morbidity. Acyclovir 400 mg BD for up to a year. Can reduce viral shedding by
up to 95%
o Can be devastating. Refer to
counselling at Sexual Health Service
· Complications:
o Risk of
AIDS transfer
o Erythema Multiforme
o Neonatal Herpes: 1 % transmission but 50% mortality
o In pregnancy:
§ If first primary episode: miscarriage, prem labour
§ If recurrent, tiny risk for baby
§ If lesions at delivery then Caesarean
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