HSV-1 vs. HSV-2: What's the difference?

HSV-1 vs. HSV-2: What's the difference?

Herpes simplex virus (HSV) comes in two main types: HSV-1 and HSV-2. Although they share many similarities and can both cause painful blisters and sores, they have different preferences, routes of transmission, and symptom patterns. In this blog post, we explain the differences between the two types and debunk some common misconceptions.

HSV-1 – the classic cause of cold sores

HSV-1 (herpes simplex virus type 1) is best known for causing cold sores around the lips and mouth. The virus is primarily transmitted through oral contact such as kissing, sharing eating utensils, or close physical contact with someone who has an active outbreak. Many people become infected in childhood(1).

However, in recent years, HSV-1 has also become an increasing cause of genital herpes, particularly in young adults in Europe and North America. This is due to changing sexual habits and increased prevalence of oral sex(2).

HSV-2 – typically associated with genital herpes

HSV-2 (herpes simplex virus type 2) is the classic cause of genital herpes and is transmitted almost exclusively through sexual contact. It is most commonly found on the genitals, buttocks, and around the anus. HSV-2 infections are typically more persistent and cause more frequent recurrent outbreaks than HSV-1(3).

An important difference is that HSV-2 has a higher risk of asymptomatic transmission, i.e. the virus can be transmitted even during periods without visible symptoms.

Comparison: HSV-1 vs. HSV-2

Property	HSV-1	HSV-2
Typical location	Mouth, lips (oral herpes)	Genitals (genital herpes)
Transmission routes	Kissing, oral contact	Sexual contact
Age at infection	Often in childhood	Often in adulthood
Outbreak frequency	Less common (in genital infection)	More frequent and more persistent
Risk of asymptomatic infection	Lower	Higher

How is HSV tested and treated?

Both types of HSV can be tested for via swabbing from an active sore or with a blood test that shows antibodies. Treatment is the same regardless of type: anti-herpes creams or gels are recommended or antiviral agents such as aciclovir can shorten outbreaks and reduce the risk of transmission1.

In the case of very frequent outbreaks, especially with HSV-2, preventive daily treatment can be considered, which significantly reduces the risk of infection to a sexual partner.

Conclusion: The most important thing is knowledge, not the type

Although HSV-1 and HSV-2 differ in location and transmission routes, both are very common and often harmless in otherwise healthy people. The main difference is how and where you get infected – and how often you get outbreaks. With openness, testing and proper treatment, it is possible to live a healthy life – regardless of which type you have.

Sources
Footnotes

1. World Health Organization (WHO). Herpes simplex virus. Fact sheet. 2020. https://www.who.int/news-room/fact-sheets/detail/herpes-simplex-virus
2. Looker KJ et al. "HSV-1 genital infection is increasing among youth", BMJ Global Health, 2017.
3. Picknall IH et al. "Global prevalence and incidence of HSV-2", The Lancet Infectious Diseases, 2022.