Herpes Simplex

Question 1

Define Herpes Simplex

Answer 1

Herpes simplex is a virus-classically defined as having 8 types
The main ones are HS1 and 2
HHV3-varicella 
HHV4-EBV
HHV5-CMV
HHV8-kaposi's sarcoma related

Cause oral, genital and ocular ulcers
Virus typically has a primary infection with clinical symptoms, then lie dormant within neuronal ganglia
Reactivation can be asymptomatic but cause tranmission

Question 2

Aetiology and risk factors of herpes simplex

Answer 2

Virus is acquired through mucosal surfaces, or breaks of the skin, where it initially replicates-then infects neurons via axons
it lies latent until weakening of the immune system, where it enters a lytic  phase and causes shedding-can be transmitted
Can be asymptomatic and symptomatic.
The main ones are HS1 and 2
HHV3-varicella 
HHV4-EBV
HHV5-CMV
HHV8-kaposi's sarcoma related
Seropositivity increases with age

Risk factors
HIV, Immunosupressed (risk for worse prognosis)
Active sexual behaviour
Young
Seropositivity:
Women, black, older

Question 3

Epidiemology of Herpes simplex

Answer 3

Worldwide, its possible that 67% of adults 0-49 have HSV1
Most commonly aquired during childhood
12% have HSV2

most common cause of genital ulcers
4% have genital herpes (due to type1)
HSV2 is present in 10% of UK youth, and cause of genital ulcer in 25% of them

Question 4

Signs and Sx of Herpes Simplex

Answer 4

Genital herpes
HSV1/2 usually starts as several vesicular lesion (smooth, bulbous, skin colour) and then progress to open ulcer
more commonly, HSV2 Causes painful Genital ulcers also tend to develop to crusted lesions
Ulcers can be in vulva, perineum, buttocks, cervix, vagina
Initial infection can also present with fever, myalgia, neck pain, neuralgia (systemic viral infection)
Women tend to have it more than men

Herpes labialis is often caused by HSV1-
painful ulcers in oral and pharyngeal mucosa
recurrent infection happens in the same area, and are preceded by tingling sensation-
They recur for about 8-48h

Primary infection-ulcers around mouth, sore throat, painful mouth, high fever
Muscle pain and lymphadenopathy
very often asymptomatic tho

Question 5

Investigations of herpes simplex

Answer 5

Genital ulcers can be HSV1/2-active lesion swab for PCR is preferred
Serology can be useful in pregnant women

Herpes labialis-clinical diagnosis can be enough
PCR of active lesion if confirmation needed