Is genital herpes mostly associated with Herpes Simplex Virus (HSV) type 2?

Genital Herpes: HSV-1 vs HSV-2 Distribution

While genital herpes has traditionally been associated with HSV-2, both HSV-1 and HSV-2 can cause genital herpes, with HSV-1 increasingly becoming a significant cause of genital herpes infections, particularly in well-resourced settings. 1, 2

Epidemiology of Genital Herpes by HSV Type

• HSV-2 distribution: HSV-2 nearly exclusively causes genital disease and has historically been the predominant cause of genital herpes 1

  • Approximately 12.1% of the United States population aged 14-49 years was seropositive for HSV-2 in 2015-2016 1
  • Most genital HSV-2 infections remain unrecognized, with only 13% of HSV-2-seropositive persons having been diagnosed with genital herpes 1

• HSV-1 in genital infections: HSV-1 is increasingly becoming a significant cause of first-episode genital herpes 2

  • This trend is particularly notable in well-resourced settings 1, 2
  • HSV-1 is associated with both oral and genital infections, with 47.8% of the US population aged 14-49 years being seropositive for HSV-1 1

Historical Perspective

Older research (1985) indicated that genital herpes was "mostly caused by HSV-2" 3, but more recent evidence shows a changing epidemiological pattern with HSV-1 playing an increasingly important role in genital herpes infections 1, 2.

Clinical Implications

• The clinical presentation of genital HSV-1 is similar to genital HSV-2, characterized by recurrent, self-limited genital ulcers 2
• Both HSV-1 and HSV-2 genital infections are lifelong conditions involving initial infection and periodic reactivation with variable viral shedding 4
• Accurate diagnosis requires type-specific molecular or virologic tests when genital ulcers are present, and type-specific serologic tests to detect antibodies when lesions are not present 2

Diagnostic Considerations

• Type-specific testing is important as it can help with:
  • Counseling about the natural history of the infection
  • Risk of transmission to partners
  • Potential for recurrence (HSV-2 typically recurs more frequently than HSV-1 in genital infections)
• Polymerase chain reaction, viral culture of active lesions, or type-specific serologic testing are the recommended diagnostic approaches 4

Treatment Approach

Both HSV-1 and HSV-2 genital infections are treated with the same antiviral medications:

• Episodic therapy: Short courses of antiviral medication during recurrences
• Suppressive therapy: Daily antiviral medication to prevent recurrences and viral shedding 2

Key Takeaway

While genital herpes has historically been associated predominantly with HSV-2, current epidemiological trends show that HSV-1 is becoming an increasingly important cause of genital herpes, especially for first episodes in developed countries. Both viruses require the same approach to diagnosis, treatment, and prevention.