Genital herpes

Question 1

Genital herpes simplex virus (HSV) - epi

Answer 1

1. DNA virus - herpes simplex type 1 (orolabial/genital) and type 2 (genital only)
2. Impossible to distinguish HSV-1 from HSV-2 on clinical appearance alone
3. 8% of men and 16% of women in Australia have had prior exposure to HSV-2
4. Over the last 30y, there has been a substantive increase in genital HSV-1 infections
5. Transmission through genital and orogenital sexual contact

Question 2

HSV - symptoms

Answer 2

1. Multiple small blisters that then break down to form shallow ulcers
2. Ulcers may be acutely painful (esp. during primary episode, which may last up to 4 weeks if not treated)
3. In women the associated dysuria may be so severe that it leads to urinary retention, requiring hospital admission and catheterisation
4. Local lymphadenopathy is common
5. Systemic symptoms during the primary episode include fever, myalgia (flu-like illness), and rarely, meningitis

Question 3

HSV - transmission/shedding

Answer 3

1. Not everyone experiences a classic primary herpes attack. Up to 75% of individuals infected have variable periods of latency before clinical symptoms occur
2. Of those infected with HSV, 90% subsequently shed the virus from the original infection site (may manifest as recurrent clinical symptoms, although these are usually less frequent and less severe as time passes)
3. Alternatively, the person may remain asymptomatic but still shed the virus intermittently
4. Transmission of virus to a sexual partner is still possible as a result of asymptomatic shedding. Around 70% of HSV infections are acquired in this way
5. Vertical transmission is also an issue (from asymptomatic transmission). In those with a hx of recurrent genital HSV, many obstetricians recommend HSV-suppressive drugs during the last trimester to reduce the risk of viral shedding at delivery

Question 4

HSV - diagnosis

Answer 4

1. PCR on swabs from the base of a suspected HSV ulcer - extremely high sensitivity. May also determine whether the virus responsible is type 1 or 2
2. In recurrent attacks, the virus sheds for only a short time and false-negative tests may occur unless the specimen is obtained immediately after symptoms occur
3. Self-collected swabs may be very useful in cases where the clinical picture suggests HSV but the dx remains unconfirmed (?)

Question 5

HSV - tx

Answer 5

1. Drug tx varies according to whether infection is primary or recurrent
2. Primary infection = 200mg acyclovir 5x daily, or 400mg TDS for 5-10d, or valaciclovir 500mg BD for 5-10d
3. Frequent recurrences may be managed with suppressive regimens of acyclovir 200mg TDS or 400mg BD, valaciclovir 500mg daily or famciclovir 250mg BD. Suppressive therapy reduces both the frequency of attacks and viral shedding
4. Most authorities recommend a break from tx every 12mo to ax whether it is still required
5. For those with less frequent attacks, episodic therapy may be useful. At the first sign of likely symptoms, the pt may commence 2-5d of therapy, which has been shown to significantly reduce the duration and severity of the attack. Topical lignocaine 5% ointment may also be useful for pain mx