What are the best methods for preventing genital herpes transmission?

Prevention of Genital Herpes

The most effective prevention strategy combines consistent latex condom use, avoidance of sexual contact during symptomatic outbreaks, and daily suppressive antiviral therapy (valacyclovir 500 mg once daily) in infected partners, which reduces transmission to susceptible heterosexual partners by 48% overall and reduces symptomatic disease by 75%. 1, 2

Primary Prevention Strategies for Uninfected Individuals

Partner Testing and Disclosure

• HSV-2-seronegative persons should request that partners undergo type-specific serologic testing before initiating sexual activity, as disclosure of HSV-2 status in heterosexual discordant couples reduces transmission risk 1
• Type-specific serologic testing can identify asymptomatic infection, since approximately 85-90% of HSV-2 infections are unrecognized and undiagnosed 3

Barrier Protection

• Consistent use of latex condoms reduces HSV-2 acquisition from women to men and from men to women and should be encouraged for all sexual exposures with new or uninfected partners 1
• Condoms provide partial but not complete protection, as HSV can be transmitted from areas not covered by condoms 3

Behavioral Modifications

• Avoid sexual contact when partners have overt genital or orolabial herpetic lesions 1
• However, recognize that sexual transmission occurs during asymptomatic viral shedding periods, which accounts for approximately one-third of transmission events 3
• Asymptomatic shedding occurs more frequently in patients with genital HSV-2 than HSV-1, and in those infected for less than 12 months 1

Transmission Reduction for Infected Individuals

Suppressive Antiviral Therapy (Most Effective Intervention)

For infected partners concerned about transmission, daily valacyclovir 500 mg once daily is the evidence-based intervention that reduces transmission risk: 1, 4, 2

• Reduces overall HSV-2 acquisition by 48% (from 3.6% to 1.9% over 8 months) 2
• Reduces symptomatic genital herpes by 75% (from 2.2% to 0.5%) 2
• Reduces HSV DNA detection in genital secretions from 10.8% to 2.9% of days 2
• Reduces clinical recurrence rates from 0.40 to 0.11 per month 2

This approach is recommended for immunocompetent individuals in heterosexual discordant relationships 1, 5, 3. While studied specifically in heterosexual couples, suppressive therapy can be considered for MSM, women who have sex with women, and transgender persons, as the mechanism works through suppression of viral shedding 1.

Critical limitation: Suppressive therapy is NOT effective for reducing transmission among persons with HIV/HSV-2 coinfection 1

Counseling Requirements

All infected individuals must receive comprehensive counseling that includes: 1

• Natural history: potential for recurrent episodes, asymptomatic viral shedding, and sexual transmission 1
• Transmission occurs even during asymptomatic periods - this is the most important concept for patients to understand 1, 3
• Abstinence from sexual activity when lesions or prodromal symptoms are present 1
• Disclosure to sex partners is essential - partners should be informed they have genital herpes 1
• Safer sex practices must be used in combination with suppressive therapy 1, 4

Type-Specific Counseling Differences

For genital HSV-1 infection: 1

• Less frequent shedding and fewer recurrences compared to HSV-2
• Transmission is less likely, particularly more than one year after infection
• Episodic therapy is recommended for recurrences
• Suppressive therapy has not been shown to reduce HSV-1 transmission to sexual partners

For genital HSV-2 infection: 1

• More frequent asymptomatic shedding
• Higher transmission risk
• Both episodic and suppressive therapy options should be discussed
• Suppressive therapy proven effective for transmission reduction

Special Populations

Pregnancy

• Women with genital herpes must inform healthcare providers during pregnancy about HSV infection 1
• Antiviral suppression is recommended starting at 36 weeks of gestation in patients with known history of genital herpes 6
• Elective cesarean delivery should be offered to patients with active lesions to reduce neonatal exposure 6

HIV-Infected Individuals

• Suppressive therapy (valacyclovir 500 mg twice daily for 6 months) reduces recurrences in HIV-infected adults on stable antiretroviral therapy 4
• However, suppressive therapy does NOT reduce HSV-2 transmission from or to HIV-seropositive persons 1

Common Pitfalls to Avoid

• Do not rely solely on episodic treatment for transmission prevention - episodic therapy does not reduce transmission risk to sex partners 1
• Do not assume condoms provide complete protection - they reduce but do not eliminate transmission risk 1, 3
• Do not assume absence of symptoms means no transmission risk - asymptomatic shedding accounts for the majority of transmission events 3
• Do not recommend routine serologic screening in asymptomatic individuals with low pretest probability (few lifetime partners, no known HSV-2 positive partners, no genital symptoms) 1

Algorithm for Prevention Approach

For uninfected individuals:

1. Request type-specific serologic testing of partners before sexual activity
2. Use latex condoms consistently for all sexual exposures
3. Avoid contact when partner has visible lesions or prodromal symptoms
4. Consider partner's use of suppressive therapy if HSV-2 positive

For infected individuals concerned about transmission:

1. Initiate daily valacyclovir 500 mg once daily (most effective intervention)
2. Disclose HSV-2 status to all sexual partners
3. Abstain from sexual activity during outbreaks or prodromal symptoms
4. Use condoms consistently during all sexual activity
5. Provide comprehensive counseling about asymptomatic shedding risk