Herpes Facts

The Herpes Virus Family

There are eight herpes viruses currently known to infect humans. These include; herpes simplex virus type-1 (HSV type-1), commonly associated with cold sores or fever blisters; HSV type-2, most commonly associated with genital herpes; varicella zoster virus, which causes chickenpox and shingles; cytomegalovirus (CMV), associated with retinitis and pneumonia in immunocompromised people; Epstein-Barr virus, which causes infectious mononucleosis; human herpesvirus 6 (HHV6), causing childhood roseola; HHV7, which results in infectious mononucleosis in children; and HHV8, associated with Kaposi’s sarcoma. Despite the extensive range of symptoms of herpes virus infections, all are characterized by the establishment of latent infection and all have the potential to reactivate from latency.

Herpes simplex virus type-1: commonly causes herpes labialis (also called oral herpes, cold sores or fever blisters), which are highly infectious open sores that crust over before healing. Although less probable, HSV type-1 can also cause genital herpes.

Herpes simplex virus type-2: a contagious sexually transmitted viral infection primarily causing genital herpes in men and women. The telltale signs of genital herpes include recurrent clusters of blisters, bumps and rashes in the genital areas and rectal lesions. HSV type-2 can also be responsible for herpes labialis, although less often than HSV type-1.

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Structure of the Virus

The HSV type-1 and HSV type-2 viruses look identical by the electron microscope.

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Genital Herpes Symptoms

Most people with genital herpes are unaware that they have the disease because they never have symptoms or do not recognize them. When they do occur, the symptoms (and severity) of genital herpes vary from person to person. First episode symptoms of genital herpes can appear within 2 to 10 days of infection and last an average of 2 to 3 weeks. In many people, the first infection may be so mild that it goes unnoticed. In other people, painful sores may appear at the site of infection. Other symptoms can include tingling, an itching or burning sensation; pain in the thighs, buttocks, or genital area; vaginal discharge; a feeling of pressure in the abdominal area; flu-like symptoms (which may include swollen glands, headache, muscle ache or fever;) and painful or difficult urination. Genital herpes symptoms are sometimes mistaken for simple skin irritation, jock itch, razor burn, or a yeast infection.

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Transmission

HSV type-1 and HSV type-2 is released from the sores that the viruses cause, but they also are released between episodes from skin that does not appear to be broken or to have a sore. A person almost always gets HSV type-2 infection during sexual contact with someone who has a genital HSV type-2 infection. A person can get HSV type-1 by coming into contact with the saliva of an infected person. HSV type-1 infection of the genitals is caused by oral-genital sexual contact with a person who has the oral HSV type-1 infection or genital contact with a person who has genital HSV type-1 infection.

Increased risk of HIV with HSV type-2 infection

There is significant evidence that there is synergism between HSV type-2 and HIV-1. These findings are bringing about a fundamental change in physicians views about the importance of Herpes testing. The paradigm shift means that concerns of physicians and health officials are in concert with those of patients with known genital herpes infections who have been concerned about transmission of the disease. Almost all new cases of genital herpes are transmitted by a person who is unaware of their HSV type-2 status. Type specific testing is important so treatment can be instituted. 

To date, there have been over 30 studies that have determined the risk for HIV acquisition among persons with HSV type-2 is fairly high. In international studies, there is the establishment of linkage.

HSV type-2 has a different natural history among HIV-infected persons. Those individuals that have both infections have more frequent HSV type-2 activations, at much higher rates of viral shedding. Finally, there are some data that HSV type-2 is associated with increased HIV plasma levels in people who have both infections. HSV type-2 may be one of the core factors to determine the progression and natural history of HIV disease. There are some early indications that suggest that treatment for HSV may be associated with reductions in plasma HIV levels.

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Pregnancy

Women with herpes can have healthy babies. However, the risk of transmission of genital herpes from an infected mother to the baby is high among women who acquire the infection near the time of delivery. The risk is lower among women with recurrent herpes at term or who acquire the infection during the first half of pregnancy. Prevention of neonatal HSV infection depends on preventing the mother from acquiring genital herpes infection during late pregnancy and avoiding exposure of the baby to herpes lesions during delivery. Type-specific serologic testing may be useful to identify women at risk of acquiring HSV when their partner has known or suspected genital herpes.

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Recurrences

After infection, the herpes virus remains inside nerve cells in an inactive, latent state. In most people, the virus reactivates from time to time and can cause new lesions to appear near the site of the original outbreak. The virus can also reactivate without causing any visible symptoms. During this time, small amounts of virus can be shed and can infect a partner (asymptomatic viral shedding.) Symptoms of recurrent episodes are usually milder than initial outbreaks and usually of shorter duration. The frequency and severity of recurrences varies greatly.

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Facts and Statistics

Transmission of the disease:

• 1 in 6 people worldwide have genital herpes caused by HSV type-2.
• HSV type-2 infects more than 1 of every 5 people in the US
• About 70% of people contracting herpes get it from a partner who is unaware they have it at the time they transmit the disease.
• Both HSV type-1 and HSV type-2 can cause genital infection.
• Genital herpes can be transmitted by genital or oral sex (cold sores).
• Viral shedding in the absence of symptoms can transmit infection.
• Transmission of herpes can occur within committed long-term relationships and in people who have never had penetrative sex through close genital contact or oral-genital contact.
• Condoms reduce the risk of transmission, but it is also advisable to avoid skin to skin contact when lesions are present.
• HSV type-2 infection increases the risk of HIV infection.

Diagnosis:

• Up to 90% of all HSV type-2 infections go unnoticed or undiagnosed because of mild or absent symptoms.
• Up to 20% of first episodes are actually reactivation of previously latent infection rather than recently acquired primary infection.
• HSV culture can frequently give false negative results.
• Accurate, type-specific serology tests can detect asymptomatic infection.

Recurrences:

• People who experience a first episode will get better. Lesions will heal and recurrences will usually be less severe.
• HSV type-2 may reactivate more frequently than HSV type-1.
• Antiviral treatment can minimize and/or prevent HSV outbreak.

Pregnancy:

• Genital herpes does not cause cervical cancer or affect fertility.
• First episode genital maternal HSV infection poses a threat to the baby.
• Neonatal herpes is serious but rare.
• Women with genital herpes can have a safe pregnancy and vaginal delivery.
• New infections need close medical follow-up.

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