STIs - Part one


- The incidence of STIs is rising rapidly.

- Asymptomatic infection is common.

- Most STIs are commonest in 16-24-year-olds.

- The National Sexual Health Strategy highlights primary care services.

- Hepatitis B can be life threatening but is preventable.


STIs are the commonest group of infections in the UK after chest infections. Recorded cases are rising (see table 1, below right), and they are a significant cause of morbidity. The rise of STIs in the youngest sexually active population is particularly worrying, and it is estimated that cases diagnosed in GUM clinics may represent only 10 per cent of the total.

HPV and chlamydia

Up to half of sexually active young women may have subclinical genital HPV infection.

Chlamydia is the UK's commonest preventable cause of infertility. The roll-out of the National Chlamydia Screening Program shows prevalence rates of up to 12 per cent in young sexually active women using primary care services.

Health benefits of prevention

Reducing the prevalence of STIs can have significant health benefits.

Chlamydia screening has been shown to reduce ectopic pregnancy and pelvic inflammatory disease (PID).

In addition these diseases may have important secondary effects through psychological morbidity and facilitation of HIV transmission.

Most STIs are asymptomatic

Most health practitioners think of testing for STIs when a patient presents with typical symptoms. But the majority of STIs in the UK are asymptomatic.

For example, up to 90 per cent of females and 50 per cent of males infected with chlamydia have no symptoms.

It is vital to identify and screen those people who are unaware that they are at high risk, both to reduce the prevalence of STIs generally and to prevent long-term complications in the individual. Subclinical infection is common, therefore transmission of STIs can easily be passed from one monogamous relationship to another.


- STIs are a common cause of morbidity.

- Up to half of sexually active young women may have subclinical HPV infection.

- Chlamydia screening can reduce ectopic pregnancy and pelvic inflammatory disease.

- Up to 90 per cent of females and 50 per cent of chlamydia-infected males are asymptomatic.

- Identifying those at high risk is important for the population and the individual.

Infection Number of cases Change since 2000
Uncomplicated chlamydia 104,155 +52%
Uncomplicated gonorrhoea 22,335 +2%
Genital warts, first attack 79,678 +12%
Genital herpes simplex, first attack 18,991 +7%
Infectious syphilis 2,254 +559%
Source: Health Protection Agency.


Some groups of the population are at higher risk of acquiring STIs.

These include people under the age of 24 years (particularly at risk of chlamydia, gonorrhoea and genital warts), and those who have had a new sexual partner in the previous three months. Also at increased risk are those with another STI, those recently separated or divorced and certain ethnic groups.

Under 24-year-olds

Young people in the UK have the worst sexual health in Western Europe.

They may have particular concerns and barriers to seeking healthcare (see table, top right).

The fact that many STIs are concentrated in young people is all the more striking in that many are not yet sexually active. About a quarter of 15-year-olds have had sexual intercourse, and suspicion of STIs, particularly of chlamydia in this group, should be high.

Caribbean heritage

A disproportionate number of cases of gonorrhoea in the UK are diagnosed in people of Caribbean heritage.

New sexual partners

Those who have had a new sexual partner in the last three months are at higher risk. Anyone can contract an STI, but statistically people are at much higher risk if they have had a new sexual partner in the recent past.

Those with another STI

People with one STI are also at high risk of having a second one. For example, about 10 per cent of people with genital warts are carrying another STI.

Diagnosis of one infection should always trigger a search for others.

Recently separated or divorced

People starting new relationships after a long period in a monogamous relationship may be less aware of current advice to reduce the risk of transmission, may not perceive themselves to be at risk, or may change sexual partners more frequently.

Gay and bisexual men

Men who have sex with other men (MSM) are at increased risk of gonorrhoea, syphilis and HIV. Over 50 per cent of gay men diagnosed with syphilis or lymphogranuloma venereum are co-infected with HIV.


Barriers to the young in accessing sexual healthcare:

- Perceived lack of confidentiality.

- Embarrassment.

- Fear of judgment.

- Fear of appearing stupid.

- Difficulty making appointments.

- Time constraints - school/home.


- Young people in the UK have the worst sexual health in Western Europe.

- About a quarter of 15-year-olds have had sexual intercourse.

- People are at much higher risk of acquiring an STI if they have had a new sexual partner in the recent past.

- People of Caribbean heritage and gay/bisexual men are at higher risk of some STIs.


The aim of taking a sexual history in a GUM clinic has different priorities to that taken in primary care. In a GUM clinic, there is a need to assess the person's risk of infection, identify which sites need to be screened (such as urethra or anus) and identify which sexual contacts may need to be assessed.

For GPs, time may be limited and testing facilities may not be available.

Sexual contact tracing is more difficult, as the contacts may not be registered with the practice. The sexual history should therefore concentrate on risk assessment.

Risk assessment

Key elements of the risk assessment are often found in the patient's notes, including age, contraception and ethnicity. Simple screening questions can be used for those at higher risk, such as whether they have had a new partner recently. Other key questions, if relevant, include when they last had sex, was it with a man or a woman, and if appropriate, do they have anal or oral sex?

Many high-risk groups may be reluctant to volunteer information for fear of judgmental attitudes or breach of confidentiality. This is especially true of the young, gay and bisexual people, and those who are married.

In the consultation use a routine for questioning, making no assumptions about the patient's sex life, and remaining morally neutral. Reflect the patient's use of language, ask them to clarify any unfamiliar terms, and remember that an embarrassed doctor leads to an embarrassed patient.

As a GP do not assume that other people have similar sexual attitudes and practices to yourself. Some examples of the true UK figures on sexual behaviour in people between the ages of 15 and 59 years old are shown above.

Sexual behaviour in men and women

Heterosexual men/women who have had anal sex in the last year 6%
Heterosexual men/women who have had oral sex in the last year 60%
Gay/bisexual men who have had anal sex in the last year <45%
Married people who have had sex with more than one men 4.5%
person in the past year women 1.9%
UK urban population who report sexual contact with men 11.9%
partner of the same sex ever women 5.6%
Men reporting sex with other men in the past five years
who have also had sex with a woman 58%
Reporting that their first sexual intercourse was within
marriage men 6.1%
women 15.9%
Source: Health Protection Agency, several recent studies.


- Simple screening questions should be used for those who may be at high risk.

- Some patients are reluctant to volunteer information about their sex life.

- Do not make assumptions.


GUM clinics see large numbers of people each year. About 8 per cent of men and 6 per cent of women aged 16-59 years have attended a GUM clinic at some time, and over 1.6 million people attended UK GUM clinics in 2004.

However, the bulk of STIs present in other settings, and GPs play a vital role in diagnosing, treating and identifying those at high risk who need onward referral. The increasing availability of urine testing for some STIs means testing and screening in the community is becoming easier.

A national strategy

The DoH is keen to encourage the role of primary care in STI management.

The national strategy for sexual health in England aims to make a comprehensive network of sexual health services available across the country.

The key role that primary care has in delivering sexual health services is highlighted, and defines three levels of sexual healthcare, each requiring increasing specialist knowledge. Level-one services should be available to all patients attending primary care (see above). Practices not offering a particular level-one service for ethical or other reasons would need to make this clear and direct patients to alternative services.

The nationally recognised STI foundation course is currently rolling out across the UK. This is a two-day course for primary care clinical staff and is designed to cover the core skills required for level-one STI services including sexual history taking and STI management. See details at

As parts of the UK have limited GUM service provision, the DoH is encouraging the development of enhanced STI services in primary care and has recently published competencies to guide primary care services who wish to develop these.

Sexual contact tracing

Treating patients without sexual contact tracing may do more harm than good. People do not become immune to bacterial STIs once an episode has been treated. Unless the patient's sexual partners are also treated the patient will contract the infection again when they resume intercourse.

Tubal damage associated with chlamydia is due to the local reaction of inflammation and fibrosis; re-infection may cause greater damage.

There are medico-legal implications for failing to counsel the patient about the importance of treating partners to prevent re-infection. Sexual partners not registered with the practice, could be registered as 'emergency' patients, referred to health advisers in GUM services, or advised to attend their own GP with a letter.

Contact tracing is vital with chlamydia, gonorrhoea, syphilis, trichomonas and PID. It is advisable in scabies, pubic lice and non-specific urethritis, but is not required in first presentation of herpes simplex or genital warts, or with candida or bacterial vaginosis.


Level-one services

- Sexual history and risk assessment.

- STI testing for women.

- Pregnancy testing and referral.

- Contraception information and services.

- Assessment and referral of men with STI symptoms.

- Cervical screening.

- Hepatitis B vaccination.


It is only possible to give general guidance on when to refer, and it also depends on the available facilities and expertise.

Referral of men

Men with urethral discharge should be referred to a GUM clinic, as should those with dysuria if they are sexually active and have no UTI. Cases of balanitis should have blood glucose checked, be treated empirically and referred if there is no response.

Referral of women

Women with discharge, dysuria, irritation or superficial dyspareunia can be treated empirically if they are low risk. Consider high vaginal swab, urine testing and if available, chlamydia and gonorrhoea NAAT's testing.

Refer as a first-line strategy if there is deep dyspareunia, pelvic pain, intermenstrual bleeding or the patient is at high risk.

In both men and women, treat first episodes of genital warts or genital herpes, but refer to the GUM clinic for STI screening.

Hepatitis B

The Sexual Health Strategy emphasises that hepatitis B is the only STI for which there is a vaccine. Hepatitis B is 100 times more infectious than HIV, and 10 per cent of those infected become long-term carriers.

Carriers are at high risk of long-term problems including cirrhosis and hepatoma.

In some groups infection is common, and 20 per cent of gay men have serological evidence of previous infection.

The UK has a selective vaccine policy that targets these groups, and GPs have a vital role in identifying and vaccinating those at risk (see table 5).


Vaccination recommended for:

- Anyone who frequently changes sexual partners.

- Gay men and bisexuals.

- Babies born to infected mothers.

- Sex workers, injecting drug users and haemophiliacs.

- Those at risk from occupational exposure.

- Those in prison for at least six months.

- Travellers to countries with a high incidence.

- People who are HIV positive.



The ABC of Sexually Transmitted Infections, edited by Adler M. BMJ Publishing Group.

Fentonk et al. Sexual Behaviour in Britain; sexually transmitted infections and prevalent chlamydia trachomotis infection. Lancet 2001; 358: 1,851-54

Competencies for providing more specialised sexually transmitted infection services within primary care. DoH. September 2005


See Medicine on the Web, page 44.


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- Shoulder problems - part two (24 February) NEXT WEEK: STIs - part two, by Dr Alan McOwan.

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