Terminology

The Venereal Diseases Act of 1917 defined 3 such diseases. They were syphilis, gonorrhoea and chancroid. In the UK, chancroid is unimportant and often forgotten although it is still troublesome in some parts of Africa. Syphilis ebbed but has been resurgent, and the prevalence of gonorrhoea is often taken as an index of the degree of promiscuity in the community.

The generic term for venereal disease (VD) was changed to sexually transmitted diseases (STDs) and the VD clinics became special clinics as new euphemisms were devised to hide the embarrassment of society. More recently the speciality was called genitourinary medicine (GUM). They are also referred to as sexually transmitted infections (STIs). The range of diseases that would meet that classification is now much wider.

Diseases which may be transmitted sexually

The number of diseases that are usually transmitted by sexual intercourse or which may be transmitted by that route, is much greater than the 3 defined by the Venereal Disease Act.^[1] The following are classified as STDs:

• Syphilis^[2]
• Gonorrhoea.^[3][4]
• Chancroid.
• HIV infection and AIDS.^[5]
• Chlamydia.^[6][7]
• Nonspecific urethritis (NSU) including Reiter's disease.^[8][9]
• Lymphogranuloma venereum.^[10]
• Genital herpes simplex.^[11]
• Genital warts.^[12]
• Carcinoma of cervix.
• Vaginal candidiasis.^[13]
• Hepatitis B and, to a rather lesser extent, hepatitis C.
• Pelvic inflammatory disease.^[14]
• Pediculosis pubis.^[15]
• Trichomonas vaginalis.^[16][17]
• Epididymo-orchitis.^[18]

Many of these diseases are covered in more detail under the specific appropriate article.

Epidemiology

• After a surge in STDs during the First World War there was a lull between wars and another surge during the Second World War. Some young men going off to war sought comfort in a way that put them at risk of acquiring STDs.
• The 1960s saw an unprecedented availability of 'the pill' and increased promiscuity, without barrier contraception. The slogan of the young was 'make love, not war' and the use of drugs became more prevalent. There was an unrealistic expectation that antibiotics could cure all STDs.
• The advent of AIDS was a chilling reminder of the limitation of antibiotics and, whilst promiscuity fell, as indicated by the incidence of gonorrhoea, this fall was only temporary.
• Young people representing 12% of the population accounted for nearly half of all STDs diagnosed in GUM clinics in the UK in 2007.^[19]
• Of particular concern is the very high rate of chlamydia and genital wart infections in girls aged 16-19 years.^[19]
• Recent reports from the Health Protection Agency (HPA) give much cause for concern.^[19] Unsafe sexual practices amongst the young are reflected in higher rates of infection.
• Some of the increases in gonorrhoea and chlamydia diagnoses among young people may reflect increased attendance of young people at GUM clinics and, for chlamydia, increased and more sensitive testing.
• Diagnoses, however, will underestimate the true level of infection in the UK, as many infections are asymptomatic.

Modes of transmission

To make a meaningful analysis of the facts and figures, it is important to look at the various ways by which the diseases may be spread. Not all such diseases are always spread by sexual activity. Transmission of infection can occur, for example, by intravenous drug abuse. Some diseases can be vertically transmitted from mother to child.

The pool of undiagnosed disease in a population is also an important problem. Such people can spread infection unwittingly. The number of people carrying undiagnosed infection varies according to the disease concerned. In many cases, infection remains undiagnosed as the individual is asymptomatic. The disease may be more likely to produce symptoms in one sex than the other, but it remains contagious. For example, a man may readily see a primary chancre of syphilis on his glans whilst a woman is unaware of one on her cervix. Candida may cause vaginal discharge and pruritus vulvae but often in men it causes no symptoms.

Risk factors

The risk of acquiring STDs is greatest in those who are promiscuous, especially if they do not use barrier contraceptives. Other factors associated with a higher incidence of STIs are:^[20][21]

• Young age.
• Failure to use barrier contraceptives.
• Non-regular sexual relationships.
• Homosexuality.
• Intravenous drug use.
• African origin (Sub-Saharan Africa).
• Social deprivation.
• Prostitution.
• Poor access to advice and treatment of STDs.

It is important to have some perspective on what constitutes 'normal' sexual activity.^[1] For example, in one 2001 UK study:^[22]

• 16-24 year-olds were found to have many more new partners.
• The average number of new heterosexual partners in the previous 5 years was 3.8 for men and 2.4 for women.
• 1/3 men and 1/5 women reported at least 10 partners in life 'so far'.
• 4.3% of men reported having paid for sex at some time.
• 14% of men and 9% of women were currently having 'affairs' (concurrent relationships).
• 5.4% of men and 4.9% of women reported homosexual contact.
• 12% of men and 11% of women reported heterosexual anal sex in the preceding year.

Comparing these findings with those from only 10 years previously shows rising levels of high-risk sexual behaviour, specifically:^[1]

• An earlier age of first sexual intercourse.
• Increased numbers of sexual partners.
• Increasing levels of unsafe sex.

Presentation

Sexual history

A sexual history is essential to guide decisions about management, or additional examinations or tests that might benefit the patient with suspected STD. It is essential that privacy be maintained. Details are covered in the separate article Sexual History Taking.

Taking a sexual history can present problems in general practice for many reasons. For example:

• Patients are often reluctant to talk about their condition because of the stigma associated with STDs.
• Patients may not appreciate that their symptoms are the result of an STD.
• Inexperience or lack of knowledge amongst GPs.
• Colluding with patients to 'play down' symptoms.
• Lack of time to assess adequately.
• The sensitivity of the subject for doctor and patient (particularly when the doctor has known the patient and family for many years).
• Problems posed by the need for intimate examinations (use of chaperones for example).

Examination

• Avoid the possibility of others walking in on the examination.
• It is usually advisable to have a chaperone when examining patients of the opposite sex.
• It is appropriate to begin with a general assessment, including vital signs, inspection of the skin and detection of signs of systemic disease.
• Remember basics before examining:
  • Ensure that the examination can be conducted in privacy.
  • Wash hands well (water and soap).
  • Use a sheet or clothing to cover the patient.
  • Position the patient and ensure they are comfortable.
  • Explain what you are about to do.
  • Put on a suitable examination glove.
  • Carry out the examination in good light.

Female patients:
There are three components to the female genital examination (assuming speculum/equipment are available):

• External genital examination:
  • Speculum examination for:
    • Vaginal discharge and redness of the vaginal walls (vaginitis).
    • Ulcers, sores or blisters.
    • Cervical abnormalities (tumours, contact bleeding or discharge).
  • Bimanual examination:
    • Ask the patient to stand up and lower his underpants to his knees (or examine with the patient in a lying position if preferred).
    • Palpate the inguinal region for enlarged lymph nodes or buboes.
    • Palpate the scrotum, feeling for the testis, epididymis, and spermatic cord on each side.
    • Examine the penis, noting any rashes or sores.
    • Ask the patient to pull back the foreskin if present and look at the glans penis and urethral meatus.
    • If there is no obvious discharge, ask the patient to milk the urethra.
    • Ask the patient to turn his back to you and bend over, spreading his buttocks slightly. This can also be done with the patient lying on his side with the top leg flexed up towards his chest.
    • Examine the anus for ulcers, warts, rashes, or discharge.

    Diagnosis

    History and examination may lead to the detection of STD which may be entirely unsuspected by the patient, particularly the asymptomatic patient (for example, STDs detected at routine cervical cytology screening).

    Investigation

    Practical guidance is available for the most appropriate tests to use in primary care to diagnose STDs from a number of sources. These are not evidence-based but provide guidance for testing in a primary care setting:
    • The Bacterial Special Interest Group of the British Association for Sexual Health and HIV (BASHH).^[23]
    • The Sexually Transmitted Infections Screening and Testing Guidelines for UK GUM clinics.
    • The local laboratory.
    More extensive testing is available by referral to a local GUM clinic. All pathology laboratories have their own operating policies. It is often important to discuss tests with the local laboratory. The processing of samples varies considerably and may depend on the clinical information provided. There are other guidelines produced from the HPA and Association of Medical Microbiologists to inform healthcare professionals working in laboratories.
    
    Tests vary around the country, so you should be familiar locally with:
    • Which swabs to take.
    • Where to swab.
    • How to take a sample.
    • Transport issues.
    • The sensitivity and specificity of tests (as false positives and false negatives occur).
    If there is a particular local need, consider:
    • Going on a Sexually Transmitted Infection Foundation (STIF) course (for example, see the BASHH link below for local venues).
    • Talking to your local GUM clinic and microbiology laboratory.

    What to test for and when

    HIV testing^[24]

    Offer and encourage an HIV test to all patients diagnosed with an STI (these are routinely done in most GUM clinics). Tests should also be offered to:

    • All sexual partners of HIV-positive individuals.
    • All men who have had sexual contact with other men, and all their female sexual contacts.
    • All patients with a history of injecting drug use.
    • All patients from a country of high HIV prevalence (>1%).
    • All patients who have had sexual contact with individuals from countries of high HIV prevalence (in the UK or abroad).

    Asymptomatic patients:

    Those at high risk of STIs are:

    • Under the age of 25; and/or
    • With a new sexual partner within the previous 12 months.

    Women:

    • Test for Chlamydia trachomatis.
    • In areas of high prevalence of gonorrhoea (or if there is a local outbreak) a test for Neisseria gonorrhoeae should be undertaken in high-risk patients.
    • Trichomonas (relatively uncommon and usually symptomatic but should be tested for).
    • It is not possible to exclude herpes genitalis by 'screening'. Only test for herpes if lesions are present.^[11]
    • In asymptomatic patients there is no value in taking samples for bacterial vaginosis or candida^[13] (neither of which is strictly sexually transmitted).

    Men:
    High-risk groups (above):

    • Urine test for chlamydia and gonorrhoea.
    • A positive test for gonorrhoea should prompt referral to a GUM clinic for a gonorrhoeal culture to be obtained (this confirms diagnosis and gives antibiotic sensitivities prior to treatment).

    Symptomatic patients

    
    Women:

    • Symptomatic women in high-risk groups (aged under 25 and with a new sexual partner within the previous 12 months): test for:
      • Gonorrhoea
      • Chlamydia
      • Bacterial vaginosis
      • Trichomonas
      • Candida^[13]
    • Symptomatic women aged over 25 years:
      • A risk assessment should be undertaken.
      • Test for chlamydia and gonorrhoea whatever the genital symptoms (if not previously performed).
      • The most common cause of vaginal discharge will be either bacterial vaginosis or candida.
      • If there has been no change in sexual partner since the last test for chlamydia/gonorrhoea, then empirical treatment based on the pH paper result, with further investigation if the symptoms do not resolve, should suffice. For normal vaginal pH, treat as if candida; for elevated pH (5.0), treat for bacterial vaginosis.
      • If there are urinary symptoms and/or lower abdominal pain, sexually transmitted organisms should be excluded in the high-risk group and considered on the basis of a risk assessment in those over the age of 25 with no change of partner.

    Men:

    • Urethral discharge and/or dysuria usually indicate an STD.^[8]
    • Ideally, a diagnosis of urethritis needs to be made for which microscopy of a Gram-stained slide is required (see separate Gonorrhoea article).
    • Tests for gonorrhoea and chlamydia are recommended.
    • Men with testicular swelling or discomfort should have STD excluded.^[18] The most common cause of these symptoms in men under 40 is C. trachomatis. A midstream specimen of urine (MSU) is also advisable to exclude a urinary tract organism as a cause of this, especially in those aged over 40.

    Management

    • Details can be found in the articles linked above under the heading 'Diseases which may be transmitted sexually'.
    • Management of STDs in children and young people is beyond the scope of this article.^[25][26]
    • Anyone who is being treated for an STI should abstain from sexual activity until treatment (their own and their partner's) is complete.
    • Single-dose antibiotics are often used, where possible, to improve compliance.

    Prevention

    The HPA report for 2008 suggests:^[19]
    • Better access for young people to sexual health services which can deliver advice, screening and treatment of STDs.
    • Interventions to promote sexual health, which are of proven effectiveness, are needed.
    • Health education to provide information and skills is needed in the area of relationship and sexual health.
    • Information to enable primary care to target preventative measures is needed.
    This is supported also by advice on prevention from the World Health Organization.^[21] The social stigma of having an STD is enormous and the GUM clinics, since their origin, have been discreet and kept anonymity for their patients. Patients are often given a number so that they do not have to present with a name. They tend to have a discreet entrance in a distant part of the hospital and, to ensure compliance, the drugs they dispense are exempt from prescription charges. It is the only part of the NHS that will not routinely inform the patient's GP of attendance.
    
    Despite anonymity and sensitivity of diagnosis, clinics will attempt to trace contacts of those with STDs. This is a very important role.
    
    Several factors have been identified as contributing to a successful programme.^[27] Adverse attitudes to the wearing of condoms must also be overcome. As explained in the article on AIDS, there has been disinformation about condoms.^[28][29][30]