Genital herpes is a very common sexually transmitted infection (STI) caused by the herpes simplex virus (HSV). About one in three people will acquire the virus in their lifetime. There are two kinds of HSV and both can cause genital herpes. HSV-1 usually causes cold sores and sometimes causes genital herpes while HSV-2 usually causes genital herpes and sometimes causes cold sores. A genital herpes infection, once acquired is lifelong, it causes an outbreak of herpes sores that eventually disappear over about 2-3 weeks. After the first episode there are typically recurrent outbreaks and these may occur only once or multiple times per year. After the first 6-12 months these recurrences usually become less frequent and less severe.
How do you get genital herpes?
Herpes simplex is a virus that is transmitted through skin to skin contact and particularly through contact with mucous membranes (the fleshy coloured parts of your body lining the mouth/anus/throat/eyelids etc). HSV is more likely to be transmitted when there is an active outbreak of sores but in over 50% of cases it is transmitted even though there are no symptoms and no sores. This is called asymptomatic shedding. Wearing condoms reduces the chance of acquiring HSV but the skin around the genitals can also transmit herpes so it doesn’t eliminate the risk altogether. Herpes is also less likely to be transmitted from somebody who is taking medications to suppress the condition.
How is genital herpes diagnosed?
It will usually be easy for a doctor to diagnose genital herpes based on the appearance of the rash it causes. Typically this starts 4-7 days after the initial sexual exposure and the first outbreak is often the worst. It is not possible to differentiate HSV-1 from HSV-2 by looking at the lesions and it is important to confirm the diagnosis by conducting a viral swab. When HSV-1 (which usually causes cold sores) infects the genital region the outbreak is usually less severe and the recurrences are much less frequent compared to HSV-2. On average there is only one recurrence with genital HSV-1 infection in the first year after infection compared to four or more times with HSV-2. For this reason (and others) it is useful to do a swab and confirm whether the infection is HSV-1 or 2.
Who should be tested for genital herpes?
All patients with ulcer sores around their genitals should be tested for genital herpes. Genital herpes is the most common cause of ulcers around the genital region but syphilis can also cause an ulcer around the genitals called a chancroid.
What happens when you get genital herpes?
In the majority of cases people who are infected with genital herpes don’t even know they have it and typically these people will also pass it on to others without realising. The nature of the rash caused by genital herpes can be very mild with very few recurrences or it might lead to multiple blisters and sores that are painful and recur frequently.
People with more severe symptoms are more likely to be diagnosed and these people often feel embarrassed or ashamed about their condition. Despite this strong emotional reaction, the condition itself is usually very mild and even when more severe it can be easily suppressed through use of medications. Over time the need to use medications becomes less relevant as recurrences tend to become less frequent. During outbreaks people with genital herpes may need to consider alternative ways to be intimate. In long term relationships the partner may consider getting a blood test to see if they have already acquired genital herpes and then the risk of transmission becomes less important.
How is genital herpes treated?
There are three main drugs used in the treatment of genital herpes – acyclovir, famciclovir and valacyclovir (there may be different brand names). A higher dose is usually need for the first episode, a lower dose is used for recurrent episodes and an even lower dose can be used when taken every day to suppress the virus from causing further outbreaks. There are no significant side effects from these medications and they are all about as effective as each other.
Patients who are have severe enough symptoms to warrant treatment can choose to treat outbreaks when they occur or they may choose to take a medication every day to stop outbreaks from occurring.
What follow up is needed?
Patients with genital herpes should be tested and treated for other STIs. If a decision is made to treat with daily medication to suppress outbreaks of genital herpes then this should be reviewed at least every 6 months to consider whether or not ongoing treatment is still required. Pregnant women are a group who require special consideration because herpes can be transmitted to the baby during delivery. The risk of this happening, however, is very low and in the vast majority of cases a vaginal delivery will still be possible.