Australian Herpes Management Forum
Testing for herpes
Health professionals have different ways of figuring out whether a person has herpes. There’s no single best way of proving that a person has herpes—every case is different and the health professional needs to use their experience to decide the best way in any given case.
If you think you have herpes, or if you’re concerned you’ve been exposed to the virus, it’s important to talk to an experienced health professional. This could be:
- a GP with an interest in sexual health
- a sexual health nurse (at a sexual health or family planning clinic)
- a medical specialist (such as a sexual health physician, infectious disease physician or a gynaecologist)
Your health professional will know the best way of looking for herpes in your case.
What methods are used?
1. History and examination
Your health professional will ask questions and listen closely as you talk about your concerns. He or she will want to know things like:
- whether you have any symptoms (blisters, sores, rash, itch, tingling/burning sensations, swollen glands, fever and so on)
- if you’re at risk of herpes (whether your partners have herpes, if you’ve changed partners recently, what type of sex you’ve had)
If you have any symptoms—and sometimes even if you don’t—your health professional will inspect your genitals and/or any other area of concern. This might include inside the vagina and on the cervix, around the anus, or the groin in general.
An experienced doctor or nurse can often give an accurate diagnosis of herpes just by listening and looking. But usually he or she will arrange a laboratory test to confirm the diagnosis.
2. Swab test
A health professional can take a swab from any suspicious-looking area, such as a blister, sore, rash or inflamed skin. This swab is then sent to a laboratory, and tested for the herpes simplex virus (HSV-1 or HSV-2). If the result comes back positive, it means that HSV-1 or HSV-2 was detected and it confirms that the blister or sore was definitely herpes.
3. Blood test
Sometimes there’s no obvious sign of herpes, but you want to find out whether or not you have the herpes virus in your body. In this case, it’s possible to have a blood test to look for herpes simplex antibodies. If you’ve ever been exposed to the herpes virus, your immune system makes these antibodies to control the infection. If you’ve never been exposed to the herpes virus, you won’t have these antibodies. If you have been exposed to herpes—even if you’ve never had any symptoms—your immune system will make these antibodies for the rest of your life and they will always be present in your blood. If the result comes back positive, it means you are carrying the herpes virus in your body. If you have a type-specific blood test, it will tell you if you have HSV-1 or HSV-2. The blood test can also tell whether you’ve recently (in the last few weeks) been infected with the herpes virus.
What are the differences between swab and blood tests?
| Swab test | Blood test | |
|---|---|---|
| When would you have this test? |
While you have symptoms that might be due to herpes, for example blisters or sores on the genitals or lips, repeated genital rash or itch, pain on passing urine. The best time for the test is less than 3 days after the symptoms have started. |
If you have some risk of contact with the herpes virus and you want to know if you’ve been infected. For example, if your partner has genital herpes and you’ve never experienced any signs of it. If you have symptoms of genital herpes but swab tests have always been negative. |
| What does a positive result mean? |
A positive result confirms that you have herpes. The test confirms which part of your body is affected. If the swab was taken from your lips, you have a cold sore, if it was from your genitals, then it’s genital herpes. A positive result from an area without a visible sore confirms that you were shedding the herpes virus from that area at that time. This is called asymptomatic shedding, and is the commonest way of passing on the herpes virus. |
A positive result confirms that the herpes virus (HSV-1 and/or HSV-2) is present in your body, and it can tell you whether it’s been there for a short time (weeks) or longer. Positive for HSV-1 only: usually means that the virus is present around the lips only, but in some cases it may be present around the genitals or even in both areas. Positive for HSV-2 only: usually (but not always) means the virus is present in the genital area. |
| What does a negative result mean? |
A negative result means that the laboratory was unable to isolate the herpes virus from the lesion or area that was swabbed. |
A negative result for both HSV-1 and HSV-2 means that you’ve never been infected with the herpes virus and you don’t have cold sores or genital herpes. |
| What can’t the test tell you? |
A negative result can’t prove that you don’t have herpes—only that the laboratory couldn’t find the virus. A negative result can’t rule out asymptomatic shedding. It only means that there was no sign of shedding from that particular area, on that particular day. |
A positive test can’t tell you which part of the body is affected: genitals, lips or somewhere else. The only way to know this is if you develop symptoms and/or to have a positive swab result. The blood test can’t prove that a given lesion is due to herpes. For example, you could have a positive blood test but symptoms due to some other condition such as thrush or a pimple. |
| What are the problems with this test? |
False negative results are common. This means that the herpes virus isn’t found, even though the person actually has herpes. It can happen if the swab was taken too late (more than 3 days after symptoms appeared) if the swab wasn’t collected properly, or if it was contaminated by bacteria or other organisms such as thrush. |
A positive result doesn’t always mean you will develop symptoms of herpes, but just knowing the virus is there can be upsetting. It raises questions of how the person was infected, which can cause relationship difficulties. The person may also be concerned about passing the virus on. This is especially difficult when there’s no way of knowing which part of the body is infectious, or when. It’s important to think very carefully about these things before having the test. |
The Australian Herpes Management Forum
The Australian Herpes Management Forum is a group of medical experts that provides resources and information about the herpes group of viruses and the conditions they cause. These include genital herpes, shingles, chickenpox, glandular fever and cold sores. If you are concerned about herpes or think that you may have come into contact with someone that has herpes, please see a doctor.
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á Top of page |
http://www.ahmf.com.au/herpes/testing.htm |
| Document Information |
Date: September 2007 |
| Where can I go for help? |
| To find a public sexual health clinic near you, see the Register of Public Sexual Health Clinics (published by the Australasian Chapter of Sexual Health Medicine) |
Australian Herpes Management Forum
c/- STIRC
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Westmead NSW 2145
Australia
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