What is the recommended treatment for new onset Herpes Simplex Virus type 2 (HSV2)?

Treatment Guidelines for New Onset HSV-2

For new onset Herpes Simplex Virus type 2 (HSV-2), treatment should include oral antiviral therapy with acyclovir 400 mg three times daily, acyclovir 200 mg five times daily, famciclovir 250 mg three times daily, or valacyclovir 1 g twice daily for 7-10 days. 1

First-Line Antiviral Therapy

The recommended regimens for first clinical episode of genital herpes include:

• Acyclovir 400 mg orally three times a day for 7-10 days, OR
• Acyclovir 200 mg orally five times a day for 7-10 days, OR
• Famciclovir 250 mg orally three times a day for 7-10 days, OR
• Valacyclovir 1 g orally twice a day for 7-10 days 1

Treatment may need to be extended if healing is incomplete after 10 days of therapy. Valacyclovir offers the advantage of less frequent dosing due to its enhanced oral bioavailability compared to acyclovir 2.

Special Considerations

Severe Disease

For patients with severe disease requiring hospitalization (such as disseminated infection, pneumonitis, hepatitis, or CNS complications):

• Acyclovir 5-10 mg/kg body weight IV every 8 hours for 5-7 days or until clinical resolution 1

Anatomical Variations

For first-episode herpes proctitis or oral infection:

• Higher dosages of acyclovir (400 mg orally five times a day) may be considered, although it's unclear if these forms require higher doses than genital herpes 1

Patient Counseling

Counseling is a critical component of managing new onset HSV-2. Key points to address include:

• Natural history of the disease, emphasizing potential for recurrent episodes, asymptomatic viral shedding, and sexual transmission
• Abstaining from sexual activity when lesions or prodromal symptoms are present
• Informing sex partners about the HSV-2 diagnosis
• Using condoms during all sexual exposures with new or uninfected partners
• Understanding that asymptomatic viral shedding occurs more frequently with HSV-2 than HSV-1, especially within the first 12 months of infection
• Risk of neonatal infection for childbearing-aged women 1

Follow-up Management

Patients should be informed about options for managing recurrent episodes:

1. Episodic therapy - Starting treatment at the first sign of prodrome or lesions:

   • Acyclovir 400 mg orally three times a day for 5 days, OR
   • Acyclovir 200 mg orally five times a day for 5 days, OR
   • Acyclovir 800 mg orally twice a day for 5 days, OR
   • Famciclovir 125 mg orally twice a day for 5 days, OR
   • Valacyclovir 500 mg orally twice a day for 5 days 1

2. Suppressive therapy - For patients with frequent recurrences (≥6 per year):

   • Acyclovir 400 mg orally twice a day, OR
   • Famciclovir 250 mg orally twice a day, OR
   • Valacyclovir 250 mg orally twice a day, OR
   • Valacyclovir 500 mg orally once a day, OR
   • Valacyclovir 1,000 mg orally once a day 1

Common Pitfalls and Caveats

• Delayed treatment: Initiating treatment as early as possible is crucial for maximum effectiveness. Efficacy decreases when treatment is started more than 72 hours after onset of first episode.
• Inadequate duration: Treatment should be continued for the full recommended course, even if symptoms improve before completion.
• Confusion with HSV-1: 5-30% of first-episode genital herpes cases are caused by HSV-1, which has less frequent clinical recurrences than HSV-2. Identifying the virus type has prognostic importance 1.
• Overlooking partner management: Sex partners should be evaluated and counseled appropriately.
• Medication adherence challenges: Valacyclovir may offer better adherence due to less frequent dosing compared to acyclovir's five-times-daily regimen 3.
• Inadequate hydration: Patients should be advised to maintain adequate hydration while taking valacyclovir 4.

Remember that while antiviral therapy controls symptoms and reduces viral shedding, it does not cure HSV-2 infection. Patients should understand that genital herpes is a chronic condition that may require long-term management strategies.