Chances of getting herpes from an infected partner.

How is herpes transmitted?

Genital herpes is transmitted via skin contact with any of the following:

Herpes transmission can happen with and without having symptoms

Chance of getting herpes when a partner has symptoms.

The chance of passing the genital herpes virus is highest when the infected person is symptomatic. It is about 20.1% [1] Transmission of genital herpes in couples with one symptomatic and one asymptomatic partner: a prospective study https://pubmed.ncbi.nlm.nih.gov/2836518/

What is considered symptomatic?
A person is considered symptomatic beginning with the prodrome period when they have a fever, chills, fatigue, muscle aches, localized skin tingling, and flu-like symptoms. This period is followed by the appearance of skin lesions that start as redness and turn into a blister and then a sore. The person is considered symptomatic until the skin has completely healed (a few days after the crust has healed)

Chance of getting herpes from a partner without symptoms.

The chance of getting herpes from an asymptomatic partner is lower, and it is about 10% per year. However, it is believed that 70% of genital herpes transmission occurs during asymptomatic virus shedding. [1] Transmission of genital herpes in couples with one symptomatic and one asymptomatic partner: a prospective study https://pubmed.ncbi.nlm.nih.gov/2836518/

So, what is asymptomatic virus shedding?
Asymptomatic virus shedding occurs when a person does not have symptoms or signs of the disease. The higher the concentration of the virus shed, the greater the chance of transmission. Virus shedding is episodic and can last from 12 hours to 3 days. Virus shedding is more frequent and lasts for more days soon after acquiring the disease, and both decrease over time. With the HSV-2 virus, shedding happens about 30% of the days a year. [6] Herpes simplex virus type 2 transmission: risk factors and virus shedding https://pubmed.ncbi.nlm.nih.gov/15319082/

HSV-2 transmission probability with unprotected sex.

The herpes transmission chance with unprotected sex varies among studies, and it is about 3-10 % per sexual act. The chance of acquisition is higher for females.

HSV-2 transmission probability with protected sex (condom).

The chances of getting herpes with a condom are much lower than with unprotected sex, and it is about 0.08-0.25% per sexual act. [3] Effect of Condom Use on Per-act HSV-2 Transmission Risk in HIV-1, HSV-2-discordant Couples https://pubmed.ncbi.nlm.nih.gov/26578538/#:~:text=Results%3A%20Transmission%20of%20HSV%2D2,per%201000%20unprotected%20sex%20acts

Condom use decreases the chance of herpes acquisition by 96% from men to women and by 65% from female to male.

However, according to a 2010 study conducted by Emily T. Martin and others, there is a risk of herpes transmission even during protected sex and no outbreak when one of the partners is herpes positive.

This is explained by the fact that herpes is transmitted skin-to-skin or skin-to-mucosa. The parts of the genitals that are not covered by a condom are open to herpes infection.

Chances of getting herpes from an infected partner on the medication

Daily antiviral medications(Acyclovir, Famciclovir, and Valacyclovir) are well-known remedies for shortening a herpes outbreak, but they can also be used as preventive tools to reduce herpes spreading.

They reduce the chance of herpes probability by about 50%.

Chance of getting HSV-2 via oral sex

The chance of passing HSV-2 via oral sex to an uninfected partner is low. Why?

The HSV-2 virus is usually a cause of genital herpes. As the name suggests, it resides in the genital region of the body—the sacral ganglia (collection of sensory nerves)—between outbreaks—this is its favorite area. However, when HSV-2 infects the oral area, it should reside locally in the trigeminal ganglia of the skull. When the HSV-2 virus resides in its unusual location, the chance of recurring symptoms and asymptomatic shedding is low.

Chance of getting HSV-1 genitally

Unlike HSV-2 transmission orally, HSV-1 transmission genitally can happen, but it is still low. The reason? As with the HSV-2 virus, the HSV-1 virus prefers to reside in its usual place (trigeminal ganglia of the head) between outbreaks. The chance of transmission is lower if it resides in the genital area.

Since most herpes transmission occurs between outbreaks with virus shedding, the HSV-1 shedding from the genital area is 11% compared to 37% in the oral area.

What are the chances of getting herpes from a woman?

The rate of transmission of genital herpes from an infected female to a healthy male is 4% over one year. [2] Risk of acquisition of genital herpes simplex virus type 2 in sex partners of persons with genital herpes: a prospective couple study https://pubmed.ncbi.nlm.nih.gov/8383724/

What are the chances of getting herpes from a man?

The rate of transmission of genital herpes from an infected male to a healthy female is 7%–31% over one year. [2] Risk of acquisition of genital herpes simplex virus type 2 in sex partners of persons with genital herpes: a prospective couple study https://pubmed.ncbi.nlm.nih.gov/8383724/

This higher rate of transmission from man to woman is explained by the fact that the herpes virus is more easily transmitted via mucosa (the moist inner lining of some organs, such as the vagina) than via “regular” skin, and females have a larger exposed area of mucosa (vagina) in their genital area than men do (penile urethra)