Genital Herpes

 Introduction:

Genital herpes is a sexually transmitted viral infection that affects the genitals or surrounding areas.   Herpes simplex virus 2 (HSV-2) is the main virus responsible for genital herpes, although a percentage of cases are caused by its close cousin, herpes simplex virus 1 (HSV-1).  Both viruses cause the same symptoms in the genital region, which are usually an outcrop of painful blisters, followed by ulcers which then crust over.  People with genital herpes usually have sporadic outbreaks of these symptoms alternating with periods without symptoms.  Individuals with genital herpes can spread the infection to their sexual partners even without an active rash in their genital region.  Although treatments to reduce the duration and severity of symptoms exist, genital herpes cannot be cured and remains the most common cause of genital ulcers worldwide.

Stain showing outline of herpes simplex virus in human tissue              
(image in public domain, courtesy of CDC/ Dr. Craig Lyeria, http://phil.cdc.gov

How common is genital herpes?

Herpes is for life

Once a person has genital herpes, he or she has genital herpes for life.  There is no way to get rid of the herpes simplex viruses in the human body once infected.  The virus will hide in nerve cells in the infected person’s spinal cord after entering the body through the skin of the genitals.  In some people, the viral infection will be sporadically activated to cause periodic active genital herpes outbreaks. Other individuals will just harbor the virus, but never have a genital rash from the infection.  Regardless, when estimating the percentage of people in the population who are infected with HSV-1 or HSV-2, it must be remembered that a person cannot be cured of this virus once infected.

Percentage of population with herpes infections

The percentage of people infected with HSV-2 in the U.S. is around 25-30%; the percentage of the U.S. population with HSV-1 is approximately 70%.  HSV-2 causes the majority  - approximately 75-85% -of genital herpes infections in most countries.  Although HSV-1 sometimes causes genital herpes, the main symptom of this infection is one or more blisters around the mouth known as common cold sores (Figure 1).  Since HSV-1 is a virus that is mainly transmitted by and confined to the mouth region, HSV-1 is acquired during childhood by saliva contact with adults or other children.  HSV-1 can spread from the mouth of one person to the genitals of another through oral sex.  The percentage of genital infections caused by HSV-1 (as opposed to HSV-2) is around 15-25% in most regions, but this proportion depends on how much oral sex is practiced in that culture.  In the U.S., rising rates of genital herpes infections due to HSV-1 have been noted in young adults due to the increase in oral sexual activity as a means of avoiding pregnancy. 

Figure 1:  Cold sore (oral herpes lesion) from HSV-1 (image in public domain,
courtesy of CDC/ Dr. Herrmann, http://phil.cdc.gov)

How is genital herpes spread?

Basically, sex
The two viruses that lead to genital herpes are generally spread sexually.  HSV-2 is generally spread during sexual contact through genital fluids, although it can occasionally be transmitted from the mouth.  As discussed above, HSV-1 usually spreads from the infected person’s mouth to the sexual partner’s genitals through oral sex.  Even though the herpes viruses are commonly spread from an infected individual to his or her sexual partner when active sores (genital or mouth blisters or ulcers) are present, a person with either oral or genital herpes can release the virus in their secretions even without active symptoms. Therefore, infected people can spread the virus and the disease to their sexual partners even when there is no evidence of a cold sore or a genital blister/ulcer.

Risk factors for getting herpes

Just like other sexually transmitted diseases (STDs), HSV-2 infection is associated with a higher number of sexual partners over a lifetime, early age of first sexual intercourse, and a previous history of other STDs.  Women are more susceptible to acquiring HSV-2 infection during heterosexual intercourse than are men.  People who sell sex for money or drugs, or who are infected with the human immunodeficiency virus (HIV) are more likely to be infected with HSV-2.  However, it is important to stress that many people who have HSV-2 don’t know they have the infection since they have never had an outbreak of genital herpes.  Those individuals without visible sores are at risk for unknowingly transmitting the virus to their sexual partners since the virus is still present in oral or genital fluids.

What are the symptoms of genital herpes?

The initial infection

As discussed above, some people are infected with HSV-2 and never have any symptoms from the infection.  Other people will have severe symptoms when they are first infected with HSV-2 or HSV-1 in their genital regions. 

 The genital areas that are most commonly involved in men are the:

·        shaft and glans of the penis

.    scrotum

·        skin surrounding the penis

·        anus 

The genital areas that are most commonly involved in women are the:

·        vagina

·        outer part of the genitals (labia)

·        cervix

·        skin surrounding the labia

·        anus

The rash after first being infected shows up about 4-7 days after the sexual exposure.  This rash can be on both sides of the penis or vagina and is composed of fluid-filled blisters (called “vesicles”), which usually change to crater-like ulcers and eventually crust over.  A feeling of tingling, numbness, pain, or itching in the regions where the rash appears is common.  When an individual is first infected, he or she can also have symptoms such as fever, swollen lymph nodes in the groin area, muscle aches, a decrease in appetite, and headaches.

Recurrent infections:

After this initial, more severe, infection, the virus hides out in nerve centers in the person’s spinal cord and then becomes active from time to time, leading to outbreaks of new genital lesions.  These recurrences of active genital blisters or ulcers from HSV-2 or HSV-1 vary from person to person.  Some people can have multiple recurrences a year, and some will only have occasional outbreaks. 

Risk factors for getting a herpes outbreak include:

·        Fever

·        Physical or emotional stress

·        Exposure to ultraviolet radiation

·        Menstruation

·        Other illnesses

·        Immunosuppression (weakening of the immune system) due to HIV or medicines

·        Mechanical irritation in the genital area

The recurrence of genital herpes usually occurs only on one side (left or right) of the penis or vagina and gives a less extensive rash than the initial infection.  The feeling of pain, tingling or numbness may still accompany these recurrent episodes.  Examples of a herpes outbreak in a man are shown in Figure 2.  Figure 2a shows the vesicles, or blisters, of a typical herpes outbreak on the penile shaft.  Figure 2b shows the later stage of male genital herpes with shallow ulcers on the shaft.  Figure 3 depicts the blisters of genital herpes around the vagina in an African-American female.

Figure 2a:  Vesicles of genital herpes on shaft of penis (image in public domain,
courtesy of CDC/ Susan Lindsley, http://phil.cdc.gov

Figure 2b:  Shallow ulcers of later-stage genital herpes on penile shaft (image in
public domain, courtesy of CDC/ Dr. N.J. Flumara, Dr. Gavin Hart, http://phil.cdc.gov

Figure 3:  Genital herpes blisters around the vagina in a female (image in public
domain, courtesy of CDC/Susan Lindley, http://phil.cdc.gov

How is genital herpes diagnosed?

Herpes can usually be diagnosed by a qualified medical provider just by looking at the patient’s genital rash.  The blisters (or “vesicles”) of herpes lesions are fairly recognizable.  However, the ulcers that appear after the blister stage can also look like the rash of syphilis or other sexually transmitted diseases, so tests are usually needed to make the definitive diagnosis of herpes. 

The various tests available for diagnosing herpes include:

·        Viral culture:  A vesicle from the genital region of a patient can be punctured and the inside fluid sent for viral culture.  The two herpes simplex viruses will grow in a special culture, called tissue culture, within five days, and can be distinguished from one another using special stains.  Although a positive viral culture is definitive for the diagnosis of genital herpes, the growth of the viruses is dependent on how the vesicle fluid is collected and the age of the blister. Therefore, a negative viral culture does not rule out the diagnosis of genital herpes, which is why this test is not performed too frequently anymore.

·        Viral PCR:  A special test called the polymerase chain reaction (PCR) can be performed on fluid from the inside of a scraped blister to look for the presence of HSV-1 or HSV-2.  This test essentially amplifies the genes (DNA) of the virus if it is present in order to diagnose the infection.  The viral PCR test is not as dependent on the conditions of collection and the vesicle as the viral culture test and is becoming more commonly used.

·        Serological testing:  Blood tests can be performed to determine if a patient has ever been infected with either HSV-1 or HSV-2.  These tests look for antibodies against either or both viruses.  In the face of a suspicious genital rash, a positive blood antibody test for either virus helps provide confirmation of the diagnosis of genital herpes.

What are the complications of genital herpes?

Although genital herpes can generally be managed with the treatments discussed below, some complications of herpes infections deserve special mention.

·        Psychological implications:  Some patients will be upset upon hearing the news that they have an incurable viral infection that may have implications for intimate sexual relationships.  The fact that this virus can be transmitted to sexual partners even when the infected individual does not have a genital rash can also be disconcerting.  Most patients respond well to reassurance and counseling about how to inform and protect future sexual partners.  The fact that effective treatments are now available to limit the pain and rash of genital herpes outbreaks and to reduce the chances of transmitting the infection to others can also be reassuring. 

·        HIV acquisition:  Any STD, including genital herpes, can predispose the infected individual to contracting HIV from an HIV-infected sexual partner.  This is because the genital herpes leads to a process of genital inflammation that makes the person more vulnerable to the entrance of the HIV virus into the bloodstream.  In addition, patients with both genital herpes and HIV are more likely to pass the AIDS virus on to uninfected sexual partners. 

·        Neonatal herpes:  Women infected with genital herpes are at risk for passing on the herpes simplex virus to their babies during pregnancy and delivery.  Women infected with either HSV-1 or HSV-2 in the genital region for the first time when they are pregnant are at greatest risk for passing the infection on to their fetus.  Women who are already infected with genital herpes prior to becoming pregnant are most at risk for passing the virus on to their babies if they have active genital sores during the delivery of the child.  Infection of the fetus or newborn can lead to very dangerous complications, including a severe herpes brain infection (encephalitis), eye involvement, lung infection, infection of the gastrointestinal tract (such as the esophagus or colon), a massive skin rash (Figure 3), or death.  Women with active genital herpes at the time of delivery can reduce the chances of passing the virus on to their baby by delivering through Caesarean section  (C-section) instead of vaginally. 

·        Disseminated infection:  Some patients can develop complications from contracting genital or oral herpes, especially if they have weakened immune systems from AIDS, other immune disorders, or are on drugs that suppress the immune system.  Such complications include brain infections (meningitis or encephalitis), infections of the esophagus (esophagitis), infection of the eye (keratitis), infection of the liver (hepatitis), infection of the lung (pneumonitis), damage to the spinal cord (transverse myelopathy), or severe oral or genital rashes that are difficult to clear.  For patients with normal immune systems, the most common complications of developing herpes are infection of the lining of the brain and spinal cord (meningitis) or infection of the lung (pneumonitis).

Figure 3:  Skin lesions from disseminated herpes simplex virus in a newborn
(image in public domain, courtesy of CDC/ Judith Faulk, http://phil.cdc.gov)

What are the treatments for genital herpes?

There are now treatments available for genital herpes that help heal existing rashes and prevent the development of new lesions.  Importantly, these treatments also reduce the shedding of the herpes viruses in genital fluids, which can protect sexual partners from contracting the infection.

There are three medications available for treating genital herpes.  Acyclovir is available both as a pill (oral formulation) and as a liquid for injection into a vein (intravenous administration).  The other two medications are only available in oral formulations and are called valacyclovir and famciclovir.

For the initial episode of genital herpes, treatment is generally administered for 7 to 10 days.  If the infection is very complicated and involves other organs besides the skin, the patient may need to be hospitalized for intravenous acyclovir.  For recurrent episodes of herpes, treatment is usually recommended for 5 days.  In addition, for patients who want to reduce the recurrence of herpes or want to protect their sexual partners from the infection by reducing shedding of the virus into genital fluids, these medications can be given daily for life.  

How can genital herpes be prevented?

The main ways to protect a sexual partner or a newborn from the spread of genital herpes are detailed below:

·        Condoms:  If used consistently and properly, condoms can help prevent the transmission of genital herpes during sex.  In fact, condoms are the best way to protect against spreading the disease through sex.  However, if active sores are present on the skin surrounding the genitals, there is still a risk of catching the infection during sexual activity. 

·        Abstinence:  Even though the virus can be spread to a sexual partner even when a genital rash is not present, there is more of a risk of catching herpes from a person with active herpes sores.  Therefore, abstaining from sexual activity during active herpes outbreaks can help prevent partners from contracting the infection.

·        Anti-herpes medications: The use of anti-herpes medications (acyclovir, famciclovir, or valacyclovir) by the infected person can help reduce the amount of virus in genital fluids and reduce the risk of transmitting the virus to a sexual partner or a newborn.

·        C-section:  As mentioned above, a cesarean delivery is recommended to avoid infecting the newborn if the mother has an active herpes rash. 

More information:

Web resources

U.S. Centers for Disease Control and Prevention (CDC) Web site on genital herpes:

http://www.cdc.gov/std/Herpes/STDFact-Herpes.htm

Mayo Clinic information Web site on genital herpes:

http://www.mayoclinic.com/health/genital-herpes/DS00179

The American Herpes Foundation:

http://www.herpes-foundation.org/