Que faire si vous pensez avoir une IST

The lights are low, the Christmas party is in full swing, and that person you have been lusting after all through the year is right there in front of you. You have both had a few Jägerbombs too many, and - as they say - 'one thing leads to another'. OK, the deed is done, and you may start feeling regretful and worried. Your head may start to fill up with all sorts of questions.

I had sex with someone I hardly know. Should I be worried?

The first thing to say is that, even if you used protection (eg, a préservatif) nothing gives you a 100% guarantee that you wont acquire an STI. Also, some STIs don't produce symptoms straightaway, or even at all. So If you've had sex with a new partner, don't delay, get tested.

These tests can be done by your GP or your local health clinic. Details of your nearest clinic will be available from your GP, your local hospital or online from the Family Planning Association's 'Find a clinic' service. In some circumstances, the NHS or private companies can arrange for you to send a sample by post. HIV home testing kits are available, but some are more accurate than others.

You've woken up the morning after with one heck of a hangover, and your bits are starting to feel sore. Is this just the genital equivalent of 'carpet burns' or the signs of something more worrying?

There are no STIs that show up the morning after. Probably the first infection to do so - which being an insect is more properly called an infestation - is pubic lice. About five days after exposure (but sometimes several weeks later), you may notice intensely itchy red spots in the pubic area and other hair-bearing areas of the body.

Gonorrhée can show up as a discharge from the vagina or penis a few days after exposure but can take up to a month. Chlamydia can produce similar symptoms about a week afterwards but can take as long as three weeks. Gale can cause itching a few days after a re-infection, but if you've never had it before, symptoms can take one or two months to appear.

Syphilis can cause a painless ulcer to appear on the genitals about 10 days after acquiring the infection but this can take up to three months. Other infections, such as hépatite B, can take at least a month to declare themselves, and some, such as VIH can take much longer.

It's worth repeating that many of these infections produce no symptoms at all. Don't wait for symptoms to appear before getting tested, because the sooner these infections are treated, the better.

There's no one size fits all answer to this, because different infections have different incubation times (the time between exposure and onset of symptoms). Most clinics advise coming as soon as possible, and then can then devise a testing strategy tailor-made for your circumstances. People can also react differently to the same infection, so the following is a rough guide:

Chlamydia

1-5 days after exposure, re-test again two weeks after treatment to check that infection has been cleared.

Gonorrhée

2-6 days, re-test again two weeks after treatment to check that infection has been cleared.

Syphilis

3-6 weeks, re-test again two weeks after treatment to check that infection has been cleared.

Hépatite B

Six weeks, re-testing not necessary, as hepatitis B remains in the system.

Herpès génital

4-6 weeks, re-test in three months if negative to confirm result.

VIH

Getting tested three months after exposure usually gives you the most accurate result. If you don't want to wait that long you can get tested sooner, but the results may be less accurate. Early detection tests can sometimes identify the virus sooner. For instance, you can get free postal HIV testing from the Terrence Higgins Trust, which uses an accurate fourth-generation HIV test to give you an answer from four weeks after possible exposure.

Seek professional advice. You''ll most likely be in shock, your mind may be numb and you may not be able to think logically at a time when you most need to. However, you will not be alone. Anyone who is sexually active can acquire an STI and there are trained professionals whose job it is to help you.

You may already be under the care of a sexual health clinic (also called a genitourinary medicine or GUM clinic) but if not, don't delay accessing their services. You will most likely be put on some treatment (usually antibiotics) depending on the type of infection. Even if you have an infection which cannot be cured (such as HIV) you'll be advised to take treatment to reduce the risk of complications. The need for re-testing will be explained to you, along with any steps you need to take to inform others and prevent the infection from spreading.

You will need to tell your current partner or partners. You should also contact any previous sexual contacts you have had in the previous few months. How far you need to go back will depend on the type of infection, but your doctor or nurse will advise you. If you do not want to contact your partner or a previous partner, the GUM clinics offer a contract tracing service.

Different people react differently to these sorts of life events. However, you may well feel panicky to start with, overwhelmed and possibly déprimé. Health professionals trained in sexual health counselling will help you cope with the diagnosis and any consequences to your long-term physical and mental health.

You'll probably want to review the sexual practices that put you at risk of an STI in the first place, and what you may need to change. You may also need to re-evaluate your relationships, particularly if it's likely you acquired the STI from a current partner.