On this page we are looking at the top five diagnosed Sexually Transmitted Infections of 2012 and look at how these may have increased or decreased in the past year and a retrospective look at how its changed in the last 10 years. We will also be looking in depth at each one and how to treat and prevent each one.

Number 1: Chlamydia

Chlamydia was diagnosed 206,912 times in 2012, but due to the changes in the way chlamydia is recorded we can't do a comparison of the previous years, however 64% of people diagnosed with chlamydia were under 25 years old.

Chlamydia symptoms

Most people who have chlamydia don’t notice any symptoms, and so don't know they have it. Research suggests that 50% of men and 70-80% of women don't get symptoms at all with a chlamydia infection. Symptoms of chlamydia could be pain when you urinate (pee), unusual discharge from the penis, vagina or rectum or, in women, bleeding between periods or after sex.

Getting tested for chlamydia

Testing for chlamydia is done with a urine test or a swab test. You don't always have to have a physical examination by a nurse or doctor. Anyone can get a free and confidential chlamydia test at a sexual health clinic, a GUM (genitourinary medicine) clinic or a GP surgery.

People under 25 years old can also get tested by the National Chlamydia Screening Programme (NCSP). This is often in places such as pharmacies, contraception clinics or colleges. You can also buy chlamydia testing kits to do at home, however, the accuracy of these tests varies. If you use one of these tests, talk to your pharmacist or GP.

Treating chlamydia

Chlamydia is easily treated with antibiotics. You may be given a single dose, or a longer course of antibiotics to take for a week. If chlamydia isn’t treated, the infection can sometimes spread to other parts of your body and lead to serious long-term health problems such as pelvic inflammatory disease and infertility (not being able to have children).

The National Chlamydia Screening Programme

Chlamydia is most common in people under 25 years old, although people of any age can get it. If you are under 25, you can get a free, confidential chlamydia test under the National Chlamydia Screening Programme (NCSP). This offers tests in various places, including some pharmacies.

Number 2: Genital Warts

Genital Warts was diagnosed 73,893 times in 2012, that's a -3% decrease since 2011 but a 15% increase since 2003.

What are they?

Genital warts are small fleshy growths, bumps or skin changes that appear on or around the genital or anal area. Genital warts are very common. In England, they are the second most common type of sexually transmitted infection (STI).Genital warts are the result of a viral skin infection caused by the human papillomavirus (HPV). They are usually painless and do not pose a serious threat to health. However, they can appear unsightly and cause psychological distress.

The human papillomavirus (HPV) is not a single virus, but a family of over 100 different strains of viruses. Most cases of infection with HPV cause no visible symptoms. Around 90% of all cases of genital warts are caused by two strains of the virus, type 6 and type 11. Other strains of HPV can cause cervical cancer.

How do they spread?

Genital warts can be spread during vaginal or anal sex, and by sharing sex toys. However, you do not need to have penetrative sex to pass the infection on because HPV is spread by skin-to-skin contact. It can take up to one year for warts to develop after infection with HPV. Therefore, if you are in a relationship and you get genital warts, it does not necessarily mean your partner has been having sex with other people. HPV is most likely to be transmitted to others when warts are present, although it is still possible to pass the virus on before the warts have developed and after they have disappeared. Condoms do not provide complete protection because it is possible for the skin around your genital area (not covered by the condom) to become infected.

Treating genital warts

If you think you have genital warts, see a health professional as they need to be treated. Wart creams available over-the-counter (OTC) will not work because they are designed to only treat warts on the hands. You can make an appointment at your local sexual health or genitourinary medicine (GUM) clinic. You can go to a sexual health clinic whatever age you are. If you're under 16, the service is still confidential and the clinic won't tell your parents. Several treatments are available, such as creams and cryotherapy (freezing the warts), and they have a good rate of success. However, many treatments can take up to three months before they are fully effective. If you are diagnosed with genital warts, it is recommended you do not have sex, including anal and oral sex, until your genital warts have fully healed. This will help prevent you passing the infection on to others. It will also help speed your recovery.

Who is affected?

Genital warts are most common in sexually active teenagers and young adults. The highest rates of genital warts occur in males between 20 to 24 years of age and females between 16 and 19 years of age.

Number 3: Herpes

Herpes was diagnosed 32,021 times in 2012, that's a 2% increase since 2011 but a massive 89% increase since 2003.

What is it?

Genital herpes is a common infection caused by the herpes simplex virus (HSV). It causes painful blisters on the genitals and the surrounding areas.

As genital herpes can be passed to others through intimate sexual contact, it is often referred to as a sexually transmitted infection (STI).

HSV can affect any mucous membrane (moist lining), such as those found in the mouth (cold sores).

Genital herpes is a chronic (long-term) condition. The virus remains in your body and can become active again. The average rate of recurrence is four to five times in the first two years after being infected. However, over time, it becomes active less frequently and each outbreak becomes less severe.

There are two types of herpes simplex virus (HSV), type 1 and type 2. Both types are highly contagious and can be passed easily from one person to another by direct contact. Genital herpes is usually transmitted by having sex (vaginal, anal or oral) with an infected person. Even if someone with genital herpes does not have any symptoms, it is possible for them to pass the condition on to a sexual partner.

At least 8 out of 10 people who carry the virus are unaware they have been infected because there are often few or no initial symptoms. However, certain triggers can activate the virus, causing an outbreak of genital herpes.

Who is affected?

Genital herpes is a common condition, especially between people aged 20-24 years. In 2011, 30,338 people attended a sexual health clinic in the UK with an attack of genital herpes for the first time.

Symptoms of Herpes

Most people with the herpes simplex virus (HSV) do not experience any symptoms of genital herpes when first infected and, as a result, they do not know they have the condition. Symptoms may not appear until months or sometimes years after you are exposed to the virus. If you experience symptoms when first infected, they usually appear four to seven days after you have been exposed to the virus.

The symptoms are usually more severe first time around than in cases of recurrent infections.

Primary infection

The symptoms of genital herpes for the first time include:

• painful red blisters that burst to leave open sores around your genitals, rectum (back passage), thighs and buttocks
• blisters and ulcers on the cervix (lower part of the womb) in women
• vaginal discharge in women
• pain when you pass urine
• a high temperature (fever) of 38°C (100.4°F) or over
• a general feeling of being unwell, with aches and pains

These symptoms may last up to 20 days. However, the sores will eventually scab and heal without scarring.

Treating genital herpes

Although there is no cure for genital herpes, the symptoms can usually be controlled using antiviral medicines. However, it is important to prevent the spread of genital herpes by avoiding sex until symptoms have cleared up and continuing to use a condom afterwards.

Number 4: Gonorrhoea

Gonorrhoea was diagnosed 25,525 times in 2012, that's a massive 21% increase since 2011, and a 9% increase since 2003. It is suggested the Gonorrhoea has increased due to it being partially drug resistant to certain antibiotics administrated.

What is it?

Gonorrhoea is a sexually transmitted infection (STI) caused by bacteria called Neisseria gonorrhoeae or gonococcus. It used to be known as "the clap". The bacteria are mainly found in discharge from the penis and vaginal fluid from infected men and women. Gonorrhoea is easily passed between people through: unprotected vaginal, oral or anal sex sharing vibrators or other sex toys that haven't been washed or covered with a new condom each time they are used.

The bacteria can infect the cervix (entrance to the womb), the urethra (tube that carries urine out of the body), the rectum and, less commonly, the throat or eyes. The infection can also be passed from a pregnant woman to her baby.

Gonorrhoea is not spread by kissing, hugging, sharing baths or towels, swimming pools, toilet seats, or sharing cups, plates and cutlery, because the bacteria can't survive outside the human body for long.

Signs and symptoms

Typical symptoms of gonorrhoea include a thick green or yellow discharge from the vagina or penis, pain when urinating and bleeding in between periods in women.

However, around 1 in 10 infected men and almost half of infected women don't experience any symptoms.

Getting tested

If you have any of the symptoms of gonorrhoea or you are worried you may have an STI, you should visit your local genitourinary medicine (GUM) or sexual health clinic for a sexual health test. Gonorrhoea can be easily diagnosed by testing a sample of discharge picked up using a swab. Testing a sample of urine can also be used to diagnose the condition in men.

It's important to get tested as soon as possible because gonorrhoea can lead to more serious long-term health problems if it's not treated, including pelvic inflammatory disease (PID) in women, or infertility.

Treating gonorrhoea

Gonorrhoea is usually treated with a single antibiotic injection and a single antibiotic tablet. This treatment is very effective and most of your symptoms should improve within a few days.

It's usually recommended that you attend a follow-up appointment a week or two after treatment so another test can be carried out to see if you are clear of infection. You should avoid having sex until you have been given the all-clear.

Who is affected?

Anyone who is sexually active can catch gonorrhoea, especially people who change partners frequently or don't use a barrier method of contraception such as a condom when having sex.

Gonorrhoea is the second most common bacterial STI in the UK after chlamydia, with most cases affecting young men and women under the age of 25. Previous successful treatment for gonorrhoea doesn't make you immune from catching the infection again.

Preventing gonorrhoea

Gonorrhoea and other STIs can be successfully prevented by using appropriate contraception and taking other precautions, such as:

• using male condoms or female condoms every time you have vaginal sex, or male condoms during anal sex
• using a condom to cover the penis, or a latex or plastic square (dam) to cover the female genitals, if you have oral sex
• not sharing sex toys, or washing them and covering them with a new condom before anyone else uses them

Number 5: Syphilis

Syphilis was diagnosed 2,978 times in 2012, that's a 1% increase since 2011 but a 49% increase since 2003.

What is it?

Syphilis is a bacterial infection that is usually passed on through having sex with someone who is infected.

The bacteria that cause syphilis are called Treponema Pallidum. They can enter your body if you have close contact with an infected sore, normally during vaginal, anal or oral sex or by sharing sex toys with someone who is infected.

Pregnant women can pass the condition on to their unborn baby, which can cause stillbirth or death of the baby shortly after labour. It may also be possible to catch syphilis if you are an injecting drug user and you share a needle with somebody who is infected. It is extremely rare for syphilis to be spread through blood transfusions, as all blood transfusions in the UK are tested for syphilis. Syphilis also cannot be spread by using the same toilet, clothing, cutlery or bathroom as an infected person, as the bacteria cannot survive for long outside the human body.

Three stages of disease

The symptoms of syphilis develop in three stages, described below.

Stage 1 (primary syphilis) Symptoms of syphilis begin with a painless but highly infectious sore on the genitals or sometimes around the mouth. If somebody else comes into close contact with the sore, typically during sexual contact, they can also become infected. The sore lasts two to six weeks before disappearing.

Stage 2 (secondary syphilis) Secondary symptoms, such as a skin rash and sore throat, then develop. These symptoms may disappear within a few weeks, after which you experience a latent (hidden) phase with no symptoms, which can last for years. After this, syphilis can progress to its third, most dangerous stage.

Stage 3 (tertiary syphilis) Around a third of people who are not treated for syphilis will develop tertiary syphilis. At this stage, it can cause serious damage to the body.

The primary and secondary stages are when you are most infectious to other people. In the latent phase (and usually around two years after becoming infected), syphilis cannot be passed on to others but can still cause symptoms.

What to do

If you suspect you have syphilis, visit a genitourinary medicine (GUM) clinic, sexual health clinic or your GP as soon as possible. The earlier syphilis is treated, the less chance there is of serious complications.

How common is it?

The number of diagnoses of syphilis has risen substantially in the past decade in the UK. There have been several local outbreaks across England, the largest of which was in London between 2001 and 2004. Rates are highest among men who have sex with men. However, syphilis is still one of the less common sexually transmitted infections in the UK.

Treating syphilis

If diagnosed early, syphilis can be easily treated with antibiotics, usually penicillin injections.

However, if it is not treated, syphilis can progress to a more dangerous form of the disease and cause serious conditions such as stroke, paralysis, blindness or even death.

Complications

It is estimated that people with syphilis are three to five times more likely to catch HIV. This is because the genital sores caused by syphilis can bleed easily, making it easier for the HIV virus to enter the blood during sexual activity. Infection with both HIV and syphilis can be serious because syphilis can progress much more rapidly than normal.

Preventing syphilis

The only guaranteed way to prevent a syphilis infection is to avoid sexual contact or to have sexual contact only with a faithful partner who has been tested and does not have the infection.

You can reduce your risk of catching syphilis and other sexually transmitted infections (STIs) by:

• using a condom during vaginal, oral and anal sex
• using a dental dam (square of plastic) during oral sex
• avoiding sharing sex toys

Matt Othold 2014 (updated October 2015)