Herpes Simplex Virus

Question 1

Definition of herpes simplex virus

Answer 1

Disease as a result of infection of either HSV-1 (majority of infections) or HSV-2
• Commonly manifests as oral (cold sores), genital and ocular ulcers

Question 2

Aetiology of herpes simplex virus

Answer 2

• Transmitted via close contact (e.g kissing, sexual intercourse) when an infected individual is shedding

• HSV-1 more commonly associated with herpes labialis (cold sores at lips)
• But now increasingly showing genital herpes
• Also associated with herpes encephalitis

• HSV-2 commonly causes genital herpes

Question 3

Pathophysiology of herpes simplex virus

Answer 3

• At primary infection:
‣ The virus would multiply in epithelial cells of mucosal surfaces (would produce vesicles and ulcers)
• THEN:
‣ The virus can enter a dormant/latent stage:
◦ It can become dormant within the sensory ganglia at the site of infection
◦ Can then cause lifelong latent infection
◦ There can then be REACTIVATION of the virus (leading to shedding and neuropathic tingling and burning)
◦ Reactivation can be due to physical and emotional stresses or Immunosuppression
◦ Triggers T cell response

Question 4

History and examination of herpes simplex virus

Answer 4

• Oral ulcer: Herpes labialis= typically single, recurrent, painful self limited ulcer/cold sore at lip border, usually HSV-1
• Genital ulcer: Genital herpes= Multiple, painful ulcers that start as vesicular lesions and can then become crusted lesions, usually HSV-2
• Dysuria: common symptom of primary genital herpes in women
• Lymphadenopathy
• Prodromal tingling sensation: usually occurs before appearance of lesion
• Gingivostomatitis: fever, sore throat and tender oropharyngeal vesicles
• Herpatic whitlow: painful vesicles on distal phalanx due to infection through break in skin
• Herpes encephalitis:
◦ viral encephalitis due to transfer of virus from peripheral site to brain via neuronal transmission
◦ Can get fever, malaise, headache, nausea
◦ Cerebral dysfunction: seizures, psychotic symptoms, memory loss etc
◦ Typically due to HSV-1

Question 5

Risk factors for herpes simplex virus

Answer 5

• HIV infection
• Immunosuppressive medications
• High risk sexual behaviour

Question 6

Investigations for herpes simplex virus

Answer 6

• Clinical diagnosis
• HSV PCR: order if lesions present
• Viral culture

Question 7

Treatment of herpes simplex virus

Answer 7

Oral or genital disease:
1) Oral aciclovir, valaciclovir or famciclovir: give for 7-10 days
+ analgesics if needed

HSV Encephalitis:
1) IV aciclovir: give as soon as suspected

Question 8

Prevention and prognosis of herpes simplex virus

Answer 8

• Avoid sexual contact when lesions are presents
• Consistent condom use

• Genital herpes and oral herpes are chronic viral infections
• 70% mortality in untreated disease