Herpes spreads through direct contact between an infected person’s skin or mucous membranes and a partner’s mucous membranes or broken skin. The virus cannot penetrate intact, healthy skin on its own. It needs a point of entry: the moist tissue lining the mouth, genitals, or anus, or a cut or abrasion elsewhere on the body. Both HSV-1 (typically oral) and HSV-2 (typically genital) follow this same basic rule, but they differ in where they tend to show up and how they get there.
HSV-1 vs. HSV-2: Different Routes, Same Virus Family
HSV-1 most commonly infects the mouth and surrounding area. It spreads through kissing, sharing saliva, or any direct contact with an active cold sore or the skin around the mouth during a period of viral shedding. Once inside, the virus travels to nerve clusters near the base of the skull, where it stays dormant between outbreaks.
HSV-2 primarily infects the genital and anal area through sexual contact. After initial infection, it settles into nerve clusters at the base of the spine. The distinction between the two types is not absolute, though. HSV-1 can spread from the mouth to a partner’s genitals during oral sex, and this has become an increasingly common cause of genital herpes. If your partner has a cold sore and performs oral sex, you can develop genital HSV-1.
Contact sports also create a transmission route. Wrestlers and rugby players can develop skin infections (sometimes called herpes gladiatorum or “scrum pox”) when abraded skin meets oral secretions or active lesions during close physical contact.
Transmission Without Visible Symptoms
One of the most important things to understand about herpes is that it spreads even when no sores are visible. This is called asymptomatic or subclinical shedding: the virus periodically reactivates and appears on the skin surface in small quantities, without causing any noticeable symptoms.
Among people with symptomatic HSV-2, the virus is detectable on the skin about 13% of days, even on days without lesions. People who carry HSV-2 but have never had a recognized outbreak still shed the virus on roughly 9% of days. In both groups, the majority of shedding days are completely silent. For people who’ve never had symptoms, about 84% of their shedding episodes happen without any visible sign at all. This means most transmission likely occurs when neither partner realizes the virus is active.
How Shedding Changes Over Time
The first year after infection is the most contagious period. During that window, HSV-2 is detectable on the skin about 34% of days. Between years one and nine, that drops to about 21% of days. After ten or more years, shedding occurs on roughly 17% of days. The amount of virus present on shedding days also decreases slightly over time.
These numbers mean the risk of passing herpes to a partner is highest early on, but it never disappears entirely. Even a decade after the first episode, the virus still reactivates frequently enough to pose a real transmission risk.
Risk Differences by Gender
Transmission does not happen at equal rates in both directions. In studies of heterosexual couples where one partner had symptomatic genital HSV-2, annual transmission rates were 11 to 17% when the male partner was the source of infection, compared to 3 to 4% when the female partner was the source. Women are more susceptible because the mucosal lining of the vagina and cervix provides a larger and more vulnerable surface area for the virus to enter.
How Effective Are Condoms?
Condoms significantly reduce herpes transmission, but the degree of protection varies by direction. A study of couples where one partner had HSV-2 found that condom use reduced per-act transmission risk from men to women by 96%, a remarkably high level of protection. From women to men, the reduction was about 65%. The difference exists because condoms cover the primary source of male shedding (the penile shaft and glans) quite well, but herpes shedding in women can occur on skin areas not covered by a male condom, such as the vulva and surrounding skin.
Condoms are most protective when used consistently, not just during outbreaks. Since the virus sheds without symptoms on many days, occasional condom use provides far less benefit than consistent use.
Transmission During Childbirth
A mother with herpes can pass the virus to her baby during vaginal delivery, and the risk depends heavily on timing. If a mother acquires herpes for the first time near the end of pregnancy and has an active primary infection during delivery, the transmission rate to the newborn can reach 60%. This is because her body hasn’t yet produced antibodies that could offer the baby some protection.
For mothers with recurrent herpes, meaning they were infected well before pregnancy, the risk drops dramatically to less than 2%. Their immune systems have already built antibodies that cross the placenta and provide the baby with partial protection. Viral shedding during recurrent episodes is also shorter and involves less virus. This is why doctors assess the timing of a mother’s infection when planning delivery.
Can You Get Herpes From Objects or Surfaces?
HSV can survive on surfaces under laboratory conditions. On plastic at room temperature, the virus remains detectable for two to three days. On glass, it can last about a day under typical indoor humidity. In very dry conditions (below 7% humidity), lab samples have remained infectious for over eight weeks at both room temperature and body temperature. Higher temperatures and humidity actually shorten survival: at body temperature in a humid environment, the virus dies within about four and a half hours.
These numbers come from controlled lab settings, though, where large amounts of virus are placed on small, clean surfaces. In everyday life, the amount of virus deposited on a glass, towel, or utensil is far smaller, and it’s exposed to air, cleaning agents, and temperature fluctuations that degrade it quickly. Researchers consider fomite transmission (catching herpes from an object) unlikely under normal, real-world conditions with standard hygiene. The overwhelming majority of herpes infections come from direct skin-to-skin or skin-to-mucosa contact with another person.
What Increases Transmission Risk
- Frequent outbreaks: More outbreaks correlate with more shedding days, including subclinical ones between visible episodes.
- Recent infection: The first year carries roughly double the shedding rate compared to long-term infection.
- Unprotected sex: Skipping condoms removes a major barrier, especially for male-to-female transmission.
- Sex during prodromal symptoms: Tingling, itching, or burning in the area where outbreaks usually occur often signals that viral shedding is happening, even before sores appear.
- Broken skin: Any abrasion, cut, or irritation on the receiving partner’s skin creates an easier entry point for the virus.
Daily antiviral medication taken by the infected partner reduces both outbreak frequency and subclinical shedding, which lowers the chance of passing the virus to a partner. Combining consistent condom use with antiviral therapy provides the greatest risk reduction available.