Herpes simplex virus type 2 (HSV-2) is a type of herpes virus. HSV-2 transmission through oral sex alone is rare, though it is possible to acquire the virus through sexual contact.

HSV-2 causes lesions, such as sores and blisters, to form on the skin. The virus is transmissible through skin-to-skin contact, and transmission can occur even when a person does not have any visible lesions.

HSV-2 is the main cause of genital herpes. HSV-1 may also cause genital herpes, although it more often causes herpes lesions around the mouth.

Although it is rare that HSV-2 spreads through oral sex, the virus can be transmissible through the genital-oral route. People with compromised immune systems have a higher risk of contracting the virus.

This article will explain how HSV transmits from one person to another. It will also suggest some steps a person can take to reduce the risk of transmission.

A man covering his mouth with his handShare on Pinterest
Hernandez & Sorokina/Stocksy

HSV-2 generallyTrusted Source passes between hosts through vaginal or anal intercourse. It is less common for this infectious agent to transmit through oral sex.

Herpes simplex virus type 1 (HSV-1) is a different form of herpes that spreads more commonly through oral sexual contact than HSV-2, according to a 2019 review of studiesTrusted Source.

HSV-1 usually causes oral lesions or cold sores but can also cause genital herpes. Oral lesions caused by HSV-1 and HSV-2 are indistinguishable from each other. People typically acquire HSV-1 during childhood or through nonsexual contact.

Some people have a higher risk than others of acquiring HSV-2 through oral sex, including:

  • people with compromised immune systems, such as those who have HIV
  • individuals receiving chemotherapy treatment
  • people taking immunosuppressant medications after an organ transplant
  • those with autoimmune conditions, such as lupus

HSV-2 is transmissible through skin-to-skin contact, which typically requires friction. It stays localized to the area it first transmits and does not travel through the body.

HSV-2 transmits more easily when an area of the body with herpes comes into contact with mucous membranes of a person who does not have the virus. Mucous membranes are moist linings in certain parts of the body, including the vagina, anus, and mouth.

If the genital area of a person with HSV-2 makes physical contact with the mucous membranes in another person’s mouth, the virus may enter the nervous system and lead to oral herpes.

Similarly, HSV-2 can pass from the mouth of a person who carries it to the genital area of another person as a result of giving oral sex.

It is not possible to acquire the virus from coming into contact with semen, touching toilet seats or other objects, or using hot tubs.

The virus may transmit more easily when lesions are present, but it can also happen when there are no symptoms. This is called asymptomatic shedding.

Oral herpes, also known as cold sores or fever blisters, occurs due to HSV-1. Over half of all adults in the United States have oral herpes, according to the American Sexual Health Association (ASHA).

Genital herpes, on the other hand, tends to be a more direct result of HSV-2 transmission. In the U.S., the ASHA estimates that 1 in every 8 people aged 14 to 49 years have HSV-2.

The majority of people who test positive for an HSV-2 infection are unaware that they carry it for the following reasons:

  • They do not display any symptoms.
  • Their symptoms are mild.
  • Doctors have linked the symptoms to a different health problem.

Both HSV-1 and HSV-2 can affect the oral or genital regions. However, having one type of HSV does not mean that an individual will acquire the other.

HSV-1 and HSV-2 are genetically similar, so the immune system of a person with herpes will produce antibodies to fight one infectious agent and potentially reduce the risk of contracting the other.

Nonetheless, it is possible to have both types of HSV at the same time.

HSV-1 and HSV-2 pass from person to person in different ways.

HSV-1 generally causes oral herpes. It is usually transmissible through kissing or the sharing of drinks and utensils.

Most peopleTrusted Source with HSV-1 acquired it during childhood through nonsexual contact and by kissing family members and friends.

Less commonly, HSV-1 may transmit to the genital area through mouth-to-genital contactTrusted Source during oral sex.

The symptoms of HSV-1 and HSV-2 are similar.

People with the virus may display no symptoms or very mild symptoms, or they may mistake their symptoms for those of a different illness. However, the virus remains transmissible, even if the symptoms are not obvious.

Symptoms may appear within days, weeks, months, or years of transmission, according to the ASHA.

Symptoms include:

  • an itching, tingling, or burning sensation around the lips and mouth or genitals
  • painful sores
  • irritated skin
  • small blisters that ooze or bleed

There is currently no cure for either HSV-1 or HSV-2. Therefore, it is important to reduce the risk of transmission.

Several precautions can help prevent the spread of HSV, including:

  • Using barrier contraception during all sexual activity: Condoms and dental dams are available for purchase in pharmacies and online.
  • Getting regular sexually transmitted infection tests: It is important to make sure that any sexual partners also receive frequent testing.
  • Limiting the number of sexual partners: If an individual limits their number of sexual partners, it reduces the risk of skin-to-skin contact with a person who has acquired an HSV infection.
  • Avoiding sexual activity during outbreaks: If a person notices any symptoms of an outbreak, such as visible lesions in the affected area, they should avoid sexual contact.
  • Taking medication: A person can talk with their healthcare professional about whether or not a daily anti-herpes medication is right for them.

Looking for physical symptoms of herpes infections is not always effective. HSV-1 and HSV-2 can pass from person to person even when no symptoms are present.

Also, using a condom or dental dam does not guarantee prevention, as a barrier cannot cover all areas that herpes can use to pass from the skin to a mucous membrane.

Both HSV-1 and HSV-2 are mainly transmissible through anal and vaginal sex. Although HSV-2 can sometimes pass from person to person through oral sex, this is rare.

Even when a person does not observe any active symptoms, it is still possible for HSV to pass from one person to another.

There is currently no cure available for HSV, so it is best to take preventive measures against transmission, such as using barrier contraception and possibly taking regular medication.

Although the symptoms can be painful and uncomfortable and precautions are necessary to prevent transmission, it is possible to live a full, sexually active life with HSV.

Anyone who suspects they have contracted HSV-2 should speak with a doctor. They can advise people on strategies to manage the virus, ways to reduce the frequency and severity of outbreaks, and methods for preventing further transmission.