In Last 20 Years, Herpes Instances Increased 30%

(Information in this report has been adapted by ScienceDaily.com from information supplied by American Academy Of Dermatology.)

(March 1, 1998) - The frequency of genital herpes in the U.S. over the last 20 years has increased according to The Centers for Disease Control and Prevention. This means that roughly 45 million people in the U.S. are seropositive for the most common cause of genital herpes, herpes simplex virus HSV-2, which amounts to about one in five people over the age of 12 who are infected with HSV-2.

The only 10% effective way to avoid contracting HSV-2 is abstinence. Many people who have genital herpes say that they abstain from sex during outbreaks because the genital ulcers that signal an outbreak can be painful, thus resulting in painful sex. Other couples abstain from sex to avoid transmitting herpes to their mates.

"[It’s common to believe that] since there is more virus present on the genitalia during an outbreak than between outbreaks. Yet, if …genital herpes was really a reliable method to prevent transmission, then why do so many people have genital herpes?" This query was posed today at the American Academy of Dermatology's 56th Annual Meeting in Orlando, by Stephen K. Tyring, MD, PhD, Professor of Dermatology, University of Texas Medical Branch, Galveston.

Herpes simplex virus (HSV) can be found on the genitalia even when no indicators are present.

Even the most careful couples may transmit HSV when there is no sign of an outbreak. This is known as asymptomatic viral shedding, which has been proven to be the cause of at least 80% of HSV transmissions.

Using condoms is another way people may try to prevent herpes transmission. But according to Dr. Tyring, "…condoms do reduce the risk of transmission of genital herpes…However…condoms can slip and/or break. In addition, condoms can only protect the skin that they cover. Many cases of herpes…can be transmitted to/from skin not covered..."

Most people who are seropositive for genital herpes never have a clinically identified outbreak. However, these people may still occasionally shed the virus and thus, transmit the disease. Even with condom use and abstaining from sex, the possibility of passing genital herpes to an uninfected partner has been estimated at 10% per year. The chance of a male passing HSV-2 to his female partner is much greater than vice versa. Actually, per year, a female’s likelihood of transmitting HSV-2 is about 30%.

Why is it necessary to study developments in the prevention and treatment of HSV-2 if there are little to no signs of it? "…the person who acquires [it]… suffers more severe and more frequent outbreaks than did the persons from whom they acquired genital herpes… If he passes it to his wife, she may suffer painful genital ulcers...The worst scenario [occurs] if she were to acquire HSV-2 during pregnancy... Another reason … is that genital ulcers facilitate … HIV…" Dr. Tyring said.

Two new techniques are being evaluated to determine their viability in decreasing instances of HSV-2: vaccinating the person at risk; or using antiviral medicines to decrease outbreaks and asymptomatic viral shedding in the person who already has HSV-2.

Studies are still being performed to verify viability of the vaccination method. Today there are vaccines for prevention of 14 viral diseases. Vaccines to prevent genital herpes are not produced from the herpes virus; they are copies of proteins on the surface of the virus. Therefore, it is not possible for a person to become infected if given the vaccination. "In fact,” Dr. Tyring said, “more than 10,000 people have received the vaccine... What remains unknown is whether [it] actually protects a person from being infected...”

People who have been vaccinated must undergo periodic blood tests for two years to find out if the amount of antibodies to HSV-2 remains high. Perhaps the best benefit to receiving the vaccine is that patients who receive it aid physicians in comparing their whether their rate of transmission against the rate of transmission of those who didn’t receive the HSV-2 vaccination.

Research is underway to determine if HSV-2 patients who receive daily treatments of antiviral medicine can lower the chance of giving HSV-2 to partners who do not have the virus. Three antiviral drugs are on the market to treat or decrease instances of outbreaks of genital herpes: acyclovir, famciclovir and valacyclovir. Taking one of these drugs daily has been shown to prevent outbreaks. Also, a daily treatment of the drug acyclovir has a 95% success rate of decreasing asymptomatic viral shedding.

As for valacyclovir and famciclovir, they are believed to also aid in decreased asymptomatic viral shedding. Since one daily dose of valacyclovir prevents clinical outbreaks in most HSV-2 patients and is assumed to have a significant effect on decreasing asymptomatic viral shedding, it may also aid in the prevention of transmission to the uninfected people. In addition to these three drugs, researchers are also seeking other methods of prevention.

Boasting more than 10,000 members worldwide, The American Academy of Dermatology is the world's biggest physicians’ organization.