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Genital Herpes Transmission From Infected Partner: What Are The Odds?
By Slava Fuzayloff | Published on May 6, 2023
An estimated half a billion people worldwide have had a genital HSV type 2 or type 1 infection. [1] Herpes simplex virus: global infection prevalence and incidence estimates, 2016 https://pubmed.ncbi.nlm.nih.gov/32514197/
Genital herpes is a very common infection in the United Statesas well, with a prevalence of 47.8% for HSV-1and 11.9% for HSV-2 among the general population 14 to 49 years old. [2] Genital Herpes – CDC Detailed Fact Sheet https://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm#ref7
The exact number of people with genital herpes is unknown because it is not a reportable condition (unlike HIV and syphilis). Moreover, routine testing for herpes (just to detect the disease) is not advised by the Center of Diseases Control and Prevention, so testing is done only on symptomatic patients (with blisters and sores) to confirm the condition. And what is more interesting is that 87% of people who test positive for herpes on blood tests have never had any clinical signs of herpes.
In this article, we will summarize the chances of getting a genital herpes infection for different categories of people:
✓ People with and without symptoms
✓ Males and females
✓ People using and not using protection
So the facts about transmission will be easier to understand, first we’ll review the basics of genital herpes: what it is, how it is transmitted, and what the risk factors are (that is, who is likely to get it).
What is genital herpes?
The term “genital herpes” refers more to the anatomic area and less to the virus type affecting it.
Both herpes types—HSV-1 and HSV-2—can cause genital herpes.
HSV-2 is the main herpes type that affects the genital area, but up to 37% of genital herpes cases are caused
by the HSV-1 virus.
[3, 4]
Six-Year Study of the Incidence of Herpes in Genital and Non-genital Cultures in a Central Kentucky Medical Center Patient Population
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC88338/
Herpes Myths vs Facts
https://www.herpes.org.nz/herpes-patient-info/myths-vs-facts#:~:text=Herpes%20Myth%3A%20Herpes%20%22cold%20sores,is%20caused%20by%20HSV%2D1.
How is genital herpes transmitted?
Genital herpes is transmitted via direct contact of healthy skin with any of the following: [5] Genital Herpes – CDC Detailed Fact Sheet https://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm#ref7
✓ A herpes sore on the skin of an infected partner
✓ Genital fluid from a partner infected with herpes
✓ Saliva from a partner infected with herpes
✓ The skin of the oral area or the mouth mucosa (inside the mouth) of a partner infected with herpes simplex virus
✓ The skin of the genital area or the genital mucosa (vagina, urethra) of a partner with herpes
Herpes transmission can happen regardless of whether an infected partner has symptoms or not.
Who has a higher chance of getting herpes from infected partner?
The chance of contracting herpes infection from an infected partner depends on many factors: [6] Risk factors for the sexual transmission of genital herpes https://pubmed.ncbi.nlm.nih.gov/1309413
✓ Gender
✓ Type of sex (including oral sex)
✓ Frequency of sexual acts
✓ Whether active herpes lesions are present
✓ Amount of time since the herpes-positive partner was infected
✓ Whether the infected partner is using herpes-suppressive medications
✓ Condom use
So, the prevalence of genital herpes in the population is not uniform. The following population subgroups are known to have a higher chance of genital herpes:
✓ Females
✓ People of African American (34.6%) or Hispanic origin (Mexican Americans have the highest incidence rate (71.7%) [7] Herpes simplex virus type 2 transmission: risk factors and virus shedding https://pubmed.ncbi.nlm.nih.gov/15319082/
✓ People with many sexual partners
✓ People who have sexual contact with commercial sex workers
✓ People of low socioeconomic and educational levels
✓ Older people—the older the person, the greater the chance they areHSV positive because the number of sex partners and amount of sexual activity increases with age
What is the chance of herpes transmission with unprotected sex?
Here, we will discuss the rate of transmission of herpes when no protection (condom, antiviral medication, etc.) is used.
Each percentage mentioned here is the per-year chance of contracting the disease (with multiple contacts) when one person is infected.
The rate of transmission of genital herpes from a symptomatic partner is 20.1%
The likelihood of contracting a genital virus is highest when the infected person is symptomatic.
A person is considered symptomatic beginning with the prodrome period, when they have 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 a 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)
The rate of transmission of genital herpes from an asymptomatic partner is 10.2%
Most of the time, a herpes-infected person is asymptomatic.
But even then, the virus can be shed by the infected skin area and transmission of the infection can occur.
It is believed that 70% of genital herpes transmission occurs during asymptomatic virus shedding. [7] Herpes simplex virus type 2 transmission: risk factors and virus shedding https://pubmed.ncbi.nlm.nih.gov/15319082/
What is asymptomatic virus shedding?
Asymptomatic virus shedding is shedding of the virus by someone who does not have symptoms or signs of the disease. Virus shedding can be measured via swab testing (but this is not done in offices).
The higher the concentration of the virus that’s shed, the greater the chance of transmission.
Virus shedding is episodic and can last from 12 hours to 3 days. [8] Herpes simplex virus-2 transmission probability estimates based on quantity of viral shedding https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006256/#RSIF20140160C18
Virus shedding is more frequent, and the virus is shed for more days, soon after acquiring the disease, and both decrease over time. [8] Herpes simplex virus-2 transmission probability estimates based on quantity of viral shedding https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006256/#RSIF20140160C18
Virus shedding also depends on the type of the virus and the area that’s affected
[9, 10]
Viral Shedding 1 Year Following First-Episode Genital HSV-1 Infection
https://jamanetwork.com/journals/jama/fullarticle/2797619
Genital Shedding of Herpes Simplex Virus Among Symptomatic and Asymptomatic Persons With HSV-2 Infection
https://jamanetwork.com/journals/jama/fullarticle/2797619
In this chart, we summarize the chance of herpes shedding in the first year after acquiring herpes.
This is not the rate of transmission of infection but rather the percentage of days per year on which people shed the virus orally or genitally.
Herpes type | Chance of oral shedding | Chance of genital shedding |
HSV-1 | 37% | 11% |
HSV-2 | 6.5% | 78% |
The rate of transmission of genital herpes from an infected* male to a healthy female is 7%–31%
The rate of transmission from an infected male to a healthy female is about two-and-a-half times higher than the rate of herpes transmission from an infected female to a susceptible (uninfected) male, which is 4%.
This 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).
The rate of transmission of genital herpes from an infected* female to a healthy male is 4%
*The term “infected partner” that we use here means a herpes-positive person, regardless of whether they have symptoms.
What is the chance of herpes transmission with protection?
According to a 2010 study conducted by Emily T. Martin and others, there is a risk of herpes transmission even during protected sex when one of the partners is herpes positive. [11] A Pooled Analysis of the Effect of Condoms in Preventing HSV-2 Acquisition https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860381/
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.
Condom use decreases the chance of herpes acquisition by 30%. [11] A Pooled Analysis of the Effect of Condoms in Preventing HSV-2 Acquisition https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860381/
What is the chance of getting herpes from infected partner on 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 against both HSV type-1 and HSV type-2. They reduce the probability of virus transmission by about 50%. [12] [Recurrent genital herpes] https://pubmed.ncbi.nlm.nih.gov/18756434/
However, this preventive tool does not seem to be feasible in practice because of its monetary cost($1,440 per year on average with daily use), psychological burden(taking medicine daily), and potential side effects (nausea, dizziness, and abdominal pain).
When someone wants to be on the preventive medication, their partner is advised to get tested as well. As we mentioned earlier, a high percentage of people are positive for herpes without having symptoms. Since herpes testing is not routinely done by doctors, it must be specifically requested.
Preventing herpes transmission
Reducing your risk of transmitting herpes boils down to three things:
✓ Taking antiviral medication
✓ Taking antiviral medication
✓ Talking to your partner about herpes
For more detailed information about herpes prevention, refer to our article on three methods on preventing the herpes transmission.
Source
STDCenterNY uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles.
-
Herpes simplex virus: global infection prevalence and incidence estimates, 2016
https://pubmed.ncbi.nlm.nih.gov/32514197/ -
Genital Herpes – CDC Detailed Fact Sheet
https://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm#ref7 -
Six-Year Study of the Incidence of Herpes in Genital and Nongenital Cultures in a Central Kentucky Medical Center Patient Population
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC88338/ -
Herpes Myths vs Facts
https://www.herpes.org.nz/herpes-patient-info/myths-vs-facts#:~:text=Herpes%20Myth%3A%20Herpes%20%22cold%20sores,is%20caused%20by%20HSV%2D1 -
Genital Herpes – CDC Detailed Fact Sheet
https://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm#ref7 -
Risk factors for the sexual transmission of genital herpes
https://pubmed.ncbi.nlm.nih.gov/1309413/ -
Herpes simplex virus type 2 transmission: risk factors and virus shedding
https://pubmed.ncbi.nlm.nih.gov/15319082/ -
Herpes simplex virus-2 transmission probability estimates based on quantity of viral shedding
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006256/#RSIF20140160C18 -
Viral Shedding 1 Year Following First-Episode Genital HSV-1 Infection
https://jamanetwork.com/journals/jama/fullarticle/2797619 -
Genital Shedding of Herpes Simplex Virus Among Symptomatic and Asymptomatic Persons With HSV-2 Infection
https://jamanetwork.com/journals/jama/fullarticle/896698 -
A Pooled Analysis of the Effect of Condoms in Preventing HSV-2 Acquisition
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860381/ -
[Recurrent genital herpes]
https://pubmed.ncbi.nlm.nih.gov/18756434/
By Slava Fuzayloff. D.O
Dr. Slava Fuzayloff is practicing STD physician with 20 years of experience and expert writer in the field of the sexually transmitted diseases.