Despite the onslaught of posters, TV commercials, public health officers and celebrities promoting safe sex over the last 20 years, rates of many sexual transmitted diseases in United States have been steadily rising. Even though about 20 percent of Americans have genital herpes, an estimated 90 percent of people infected with the virus don't realize that they have it. And passing the virus unknowingly to unsuspecting partners may partially explain the increase in genital herpes rates.
Genital herpes can cause outbreaks involving painful blisters and flu-like symptoms, but symptoms can also be mild—and sometimes people don't have any outward signs of infection. Not surprisingly, herpes is most often transmitted when people are not symptomatic. An equally worrisome feature researchers have discovered is that people with herpes are at a higher risk for getting and transmitting HIV.
Below, Dr. Anna Wald, an associate professor at the University of Washington and medical director of the Virology Research Clinic, provides an overview of the herpes simplex virus, which causes both oral and genital herpes.
What is herpes simplex?
Herpes simplex virus is one of eight known human herpes viruses. It belongs to a family of DNA viruses that have infected humans for a long time. One of the somewhat unique characteristics of herpes is the fact that it establishes latency in the host, meaning that once someone is infected, the virus stays in the body for the rest of your life.
Within the herpes simplex virus group, there are two types: herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2). Historically, herpes simplex 1 has been associated with cold sores or fever blisters on the mouth and lips. And HSV-2 has been thought to be the primary cause of genital herpes. However, because of oral-genital contact, doctors are also seeing quite a bit of genital HSV-1.
What are the symptoms?
Most people who have HSV-2 don't know that they have genital herpes because they either have no symptoms or their symptoms are mild and infrequent. But classic symptoms, which are present in a minority of the people infected, are different with primary infection and what doctors call recurrences. The primary infection can be a major illness with fever, chills, flu-like symptoms and genital ulcerations. These often start as blisters and then they break down into ulcers, or sores. In many people, the lesions hurt a lot and are very tender to touch.
"With a recurrence what we see is also an outbreak of ulcerations," says Wald, "but the outbreak is usually smaller and doesn't last as long."
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But it's also important to know that there is a phenomenon called asymptomatic shedding. This means that the virus can be present in the genital or oral tract on days in which there are no lesions, no ulcers. And that's when most of the transmission occurs.
Why are so many people with genital herpes undiagnosed?
"I think it's probably a combination of reasons," says Wald. "Nobody likes to think of themselves as having genital herpes, so they come up with an alternative self-diagnosis." And sometimes physicians don't diagnose people properly because their symptoms are mild, or they won't think of herpes because the presentation is somehow atypical. Less typical presentations can be confused with other conditions such as yeast infections, urinary tract infections and scabies.
How is the virus usually transmitted?
HSV-1 is spread through oral or oral-genital contact. HSV-2 is transmitted through sexual contact. Then there are rare cases of mother to child transmission. That usually occurs during birth. While it's a rare event, it's often devastating. The risk of transmission is highest when the woman acquires herpes for the first time towards the end of pregnancy.
How often do recurrences occur?
On the average, about four times a year, but some people can have one or two recurrences a month, while others may have one a year. So it's really variable. They usually occur less frequently as time goes on.
What can trigger an outbreak?
"We don't know," says Wald. "We know that in certain situations fever will trigger oral HSV recurrence." Also, any surgery that manipulates or somehow stimulates the nerves where the virus resides can cause the virus to reactivate. So for example, any surgery on the jaw or on the teeth can lead to reactivation and outbreak of HSV-1. Triggers for genital herpes are less well established.
So is there any safe time during which someone is not contagious?
On any given day there is some risk that one is shedding the virus. Although people are most contagious when they are having an outbreak, experts think that most transmissions occur when somebody is not having an outbreak.
"If you know you have herpes and you're having an outbreak, chances are you're not engaging in sexual activity, because you don't want to give it to your partner. Also it may be somewhat uncomfortable," says Wald. But if you're not having an outbreak, then people aren't as conscious of the virus or transmitting it to others.
What can be done to prevent transmission?
"We think it's very important for people to tell their partners that they have genital herpes," says Wald, "because that's an issue of trust. Each couple needs to decide what kind of risk is acceptable to them."
"We recommend never having sexual contact when there is an outbreak," says Wald, "and using condoms at all other times." There have been studies that have followed people taking an anti-viral drug for herpes and found that it can reduce the risk of transmission by 50 percent.
What tests are given to diagnosis genital herpes?
Unfortunately, most herpes cases are still diagnosed by the physician looking at the ulcer and saying, "This is herpes." "In our experience, that is not an accurate way to diagnose herpes, because most of the cases will be missed," says Wald. Some people will not have a lesion, and others will have lesions that will be look atypical. Additionally, people have been diagnosed with herpes based on a physical exam when, in fact, they did not have it.
"I would recommend that the diagnosis of herpes be confirmed with a laboratory test," says Wald.
The test that is done most often is a viral culture. A swab is rubbed on the lesion and that is sent to the laboratory where the virus is grown. "Unfortunately, we find that especially with recurrent disease, the culture is often negative. Then we don't have any information whether the patient did or did not have herpes infection," says Wald, "and we can't make a definitive diagnosis."
More doctors are moving away from the viral culture and towards a blood test that can confirm the presence of herpes' antibodies. These tests do not rely on having an ulcer at the time of the diagnosis, and can be done at any time. The problem is that, until recently, they have not been able to accurately distinguish between antibodies for HSV-1 and HSV-2. In fact, some of these older tests are still on the market and are inaccurate. But there is now a Food and Drug Administration approved test for HSV antibodies that can accurately distinguish between the two viruses.
What kind of treatment is available?
There are three antiviral medications for herpes that are currently FDA approved. These drugs are equally effective and can either be used during outbreaks or suppressively, meaning they can be taken every day to prevent recurrences. One of the drugs is available as a topical cream, but it's not very effective and experts discourage its use.
How are genital herpes and HIV linked?
Herpes simplex can cause severe disease in immunocompromised patients. More recently it's become evident that having genital herpes increases your risk of acquiring HIV and probably increases your risk of transmitting HIV. It increases your risk of acquiring HIV because it causes genital ulcers that provide an easier entry for HIV. In addition, the kind of cells that come to the herpes lesion to help repair the damage are CD4 cells and those are the cells that serve as entry cells for HIV to the body.
In terms of transmission, people who have HIV and HSV-2 appear to have HIV present in the genital ulcers that are caused by herpes. They're shedding more HIV and therefore they're more infectious.
What kind of emotional impact can herpes have?
"I think the diagnosis of herpes is always very shocking despite the fact that 22 percent of people in the United States have genital herpes" says Wald. Most people who have herpes never thought that they were at risk for it.
"I think the short-term or the medium-term emotional impact can be great," says Wald, "but over time, most people become much more comfortable and manage the disease effectively, and it does not interfere in their lives."
It is helpful to have good information about the disease. People should know that if they had a severe primary outbreak, recurrences will never be that bad, and that there are ways to effectively suppress the disease with a daily antiviral and ways to reduce the risk of transmission.
