HSV

• Overview:

  • STI caused by the Herpes simplex virus
  • Transmitted via skin-to-skin contact through vaginal, anal or oral sex
  • Once infected people may be asymptomatic for a long period of time, until the first flare up
  • Following the primary symptomatic infection, the virus can lie dormant for years and cause recurrent outbreaks
• There are two types of HSV:

  • HSV-1: most common cause of anogenital herpes, labial (oral) herpes (and corneal infection)
  • HSV-2: anogenital herpes and occasionally oral herpes
  • Double stranded DNA virus
• Infection with HSV-1 does not confer immunity to HSV-2 and vice versa. 
• After initial infection, the virus lies dormant within local sensory ganglia. HSV is, therefore, a lifelong infection with periods of reactivation and symptoms.
• Risk factors:

  • Multiple sexual partners
  • Oral sex with a partner suffering from cold sores
  • Can still be transmitted with the use of barrier contraception - especially if the virus is present on genital areas not covered by the barrier
• Primary infection symptoms:

  • Small red blisters around the genitals that are very painful and can form open sores
  • Female blisters - vulva, clitoris, buttocks and anus
  • Males - penis, anus, buttocks and thigh
  • Lesions crust and heal after around 20 days
  • Vaginal or penile discharge
  • Flu-like symptoms, fever, muscle aches
  • Itchy genitals
• Secondary infection symptoms:

  • Usually milder and shorter
  • Burning and itching around the genitals
  • Painful red blisters around the genitals
• Investigations:

  • Swab from open sore (from base of ulcer, lesion should be burst)
  • PCR can differentiate between type 1 and 2
  • Screen patients for other STIs if the history suggests they are at risk
• Management:

  • Symptomatic episodes treated with aciclovir for 5 days - should be commenced within 5 days of symptom onset
  • Pain control - saltwater baths, topical petroleum jelly, oral analgesia or topical lidocaine
  • No requirement for contact tracing but refrain from sexual intercourse whilst lesions present
  • If experiencing prodromal symptoms (tingling) - treatment can be started before lesions develop to prevent or minimise outbreak
  • Prophylactic treatment with aciclovir can be considered in patients experiencing multiple episodes or wishing to reduce onward transmission
• Complications:

  • Urinary retention: may require catheterisation
  • HSV keratitis: dendritic lesion on the cornea
  • Aseptic meningitis
  • Herpes proctitis
  • Neonatal HSV: an increased risk if the mother becomes infected in the third trimester
  • Herpetic whitlow (painful infection of the finger)
• HSV in pregnancy:

  • Dangerous from the baby if the mother contracts HSV in the third trimester - mother has not produced antibodies to pass on
  • More likely to contract herpes during birth - caesarean recommended
  • 3 forms of neonatal herpes - skin eyes and mouth (SEM) herpes, disseminated herpes affecting the internal organs, and CNS herpes that can lead to encephalitis
  • Antiviral treatment is usually sufficient for SEM herpes but mortality much higher for disseminated and CNS herpes