Genital herpes is caused by a virus called herpes simplex. There are two types of this virus: type I and type II. Type I mainly causes cold sores of the lips. It is a very common infection that affects many people in childhood. Sometimes they do not even know they have it.

The second type of herpes virus mainly infects the genital region, but can sometimes spread to the mouth during oral sex with someone who is infectious.

These two herpes viruses belong to a family of viruses called herpes viruses. In the same family of viruses are chicken pox virus ( Varicella-zoster virus) and the virus that causes glandular fever ( Epstein-Barr virus), also known as kissing disease or infectious mononucleosis. Cytomegalovirus, which is the most common viral cause of birth defects in babies also belongs to this family group. A newly discovered member of this family is the human herpes virus 6, and again research is showing it to be quite a common infection, especially in childhood. It is not thought to cause genital infection.

All the viruses in the herpes family have in common that once they infect a person, the infection stays in the cells of that person's body for the rest of their life. The viruses can become active again later in their life, possibly making them sick and infectious again.

Are all types of genital herpes the same?

No. There are different strains. Some apparently never cause repeated outbreaks, others are more severe. In addition each person reacts differently to a herpes infection, some people having many recurrences, others with the same strain having few or no recurrences. If you have genital herpes and you meet someone else with genital herpes you should still make sure that you take steps to avoid catching their type.

How do you catch the herpes virus?

Type I herpes is usually caught in early childhood from other children, but it can be caught at any time in your life from someone who is infectious. This virus is usually caught by kissing or by droplet spread, from sneezing or coughing. It can also be caught by oral sex. Someone with the sores on their mouth or lips can spread it to the genitals of a partner, who can then pass it back to their genitals during sexual intercourse. Type I herpes which is transferred to the genitals does not change into type II herpes. It is usually only a problem for the first outbreak in the genitals.

Type II herpes is usually caught by sexual intercourse with someone else who has it and is infectious. It can also be caught in the mouth via oral sex.

New studies are showing that genital herpes infection is far more common than it was first thought. Many people with the infection do not even know they have had it. Some people who know they have had it cannot tell if they are having a recurrence and therefore are infectious.

I had sex with someone with herpes, will I get it?

Probably not. It depends how infectious they were and how good your own immunity is. If you were unfortunate enough to catch it, the symptoms will usually appear within two to 14 days, although it has been known to take as little as 24 hours or as long as years. Some people catch it but never develop symptoms. Most often people with herpes cannot be sure who they caught it from.

What is it like to have herpes?

In the first outbreak (primary infection) most people feel generally miserable and unwell. Often they have a temperature and mild headache. There is soreness and itching where the infection is and there may be some discomfort passing urine. The local lymph glands are usually quite swollen and sore. In women there is often a vaginal discharge, and there may be an associated yeast infection. Small blisters may be seen on the skin of the penis and the vulva or sometimes other areas of skin close to the genitals. These are full of infectious herpes simplex virus. Usually they burst after a few days, leaving a small sore that heals over with a scab and falls off leaving no scar. The first infection can last up to three weeks without treatment.

If you think you are having an outbreak of genital herpes infection for the first time, go and see your local doctor or a doctor at an STD clinic. There is very good treatment to make you feel better within 24 hours and stop the infection spreading further than it already has. It is important for the doctor to do tests to find out what sort of infection it is you have, in particular whether it is type I or type II herpes simplex infection. You should also be checked to make sure you do not have any other infection as well.

Another good reason for being checked is that the symptoms or signs you are experiencing may not be herpes. I see many people who think they are having herpes recurrences when in fact it is not that at all.

How is herpes diagnosed?

The usual test for genital herpes is to take some fluid from the blister or ulcer and grow the virus. The virus can grow in 48 hours but sometimes it grows quite slowly, taking up to a week. If the test is negative it does not prove absolutely that you don't have herpes, as there is a chance the virus wasn't picked up in the test. If you're not sure and the symptoms recur, have the test repeated within 24 hours of the recurrence.

Blood tests are not usually accurate enough to diagnose the type of herpes infection which has occurred.

What happens after the first outbreak of herpes?

If you catch type I herpes in the genital area it is probable that you will never again have another outbreak of that infection there. This is why it is a good idea if you think you might have an infection with genital herpes to see your doctor and have tests to find out what sort of infection it is. You will certainly feel much better if you find out that it is only herpes type I.

If you have just had your first infection with type II herpes don't be dismayed, the news is not as bad as it seems. You have a better than 50% chance of never suffering another outbreak! Be optimistic and hope that you will be one of the lucky majority.

Recurrences

Recurrences are milder than the first outbreak, and usually they become less severe and less frequent with time. Recurrences occur because the virus, once it gets into the body, stays in the nerve cells. For various reasons the virus travels down to the skin surface where it may be associated with an outbreak.

Sometimes just prior to a recurrence people get a funny feeling or an itch, and then blisters appear. (Putting ice on the spot when it becomes itchy may stop the outbreak, but this does not work for everyone.) Others have slightly stronger feelings and yet others may have no symptoms at all, even if there is a small blister or sore.

People with a recurrence are infectious from the prodrome, which is the first abnormal feeling in the area, until all the scabs have fallen off, or the skin has healed over.