How to Report HSV-1 Positive, HSV-2 Negative Results to Patients
Tell the patient they have antibodies to HSV-1, which is extremely common (affecting nearly half of US adults) and typically causes oral cold sores, though it can also cause genital herpes, and that they do NOT have HSV-2, the type more specifically associated with genital herpes 1.
Key Communication Points
Frame the Result Appropriately
- Emphasize that HSV-1 seropositivity affects 47.8% of the US population aged 14-49 years 1, making this an extremely common finding that does not necessarily indicate active disease or recent infection
- Most HSV-1 infections are oral (cold sores/fever blisters), acquired in childhood through non-sexual contact
- The presence of antibodies means exposure at some point in life, but does NOT indicate when infection occurred or whether the person has ever had symptoms
Address the Clinical Significance
The critical distinction is that HSV-1 antibodies alone do not diagnose genital herpes 1. Explain:
- If they have never had genital symptoms, this likely represents oral HSV-1 infection (or asymptomatic infection)
- If they DO have genital symptoms, type-specific testing from lesions (PCR or culture) is needed to determine if HSV-1 is causing genital disease
- HSV-1 is increasingly causing first-episode genital herpes, particularly in well-resourced settings 1
Important Caveats About the Test
Ensure the patient understands that only glycoprotein-G-based serologic tests are accurate 2. Mention:
- Non-gG-based tests have false-positive rates of 14-88% for HSV-2 when HSV-1 antibodies are present 2
- Even with proper gG-based tests, false-negative results occur in 12-30% of people with documented HSV infection 3
- The negative HSV-2 result is reassuring but not 100% definitive if tested early after potential exposure
Transmission Counseling
For HSV-1 positive patients:
- If oral HSV-1: avoid kissing or oral contact during cold sore outbreaks; virus can shed asymptomatically but risk is lower
- If performing oral sex, HSV-1 can be transmitted to a partner's genitals
- Condoms reduce but do not eliminate transmission risk for genital HSV-1
What This Means for Their Health
Reassure that HSV-1 seropositivity without HSV-2 carries minimal health risks for most people:
- No increased risk of HIV acquisition (unlike HSV-2, which confers 3-fold increased HIV risk) 1
- Recurrences of genital HSV-1 are typically less frequent than genital HSV-2
- Most people with HSV-1 antibodies never have recognized symptoms 1
Common Pitfalls to Avoid
- Do not order HSV serology for screening asymptomatic patients without specific indication - the CDC guidelines do not recommend population-based screening 1
- Do not diagnose "genital herpes" based on serology alone - serologic tests cannot determine the anatomic site of infection 4, 5
- Do not assume HSV-1 positive means recent infection - antibodies persist lifelong after any exposure
- Avoid creating unnecessary anxiety - frame this as a common finding that most often has no clinical significance