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Chlamydia: detection, treatment and follow-up

Angela Star
Assistant Lead, Sexual Health Services
Community Health Services, NHS South of Tyne and Wear

Chlamydia is one of the most commonly diagnosed sexually transmitted infections, and many nurses working across a variety of disciplines and settings can help reduce the incidence of the condition

Chlamydia trachomatis is an intracellular bacterium that is very easy to transmit through sexual contact. Since 1999, the incidence of chlamydia has risen 116%, despite the fact that specialist skills and training are not required to detect this infection.1 Anyone who has unprotected sexual contact is potentially at risk of contracting and sharing sexually transmitted infections.

Chlamydia can be easily passed between partners through penetrative intercourse (vaginal and rectal) but also through other forms of sexual contact; for example, oral, pharyngeal, conjunctiva or use of sex toys without appropriate barrier or condom use. Infection of the conjunctiva can occur in the newborn delivered vaginally to a mother with known or unknown chlamydial infection. It is also possible, but rare, for patients with complicated or untreated infection to develop reactive arthritis. This is more common in men than women, causing inflammatory response in joints and eyes.

Prolonged exposure to chlamydia by chronic infection or frequent reinfection causes long-term chronic pelvic pain and tubal damage, and leads to infertility in about 5-18% of patients (male and female). Prevention of these complications can be avoided through regular screening (at each change in partner), although this relies on prompt treatment and effective contact tracing.

Those at highest risk have been identified as young people aged 15-24 years; anyone with a new sexual partner or more than one partner in the last year; and poor use of barrier methods (male and female condoms). Not everyone who has chlamydia infection has symptoms, which is why opportunistic screening is important. This is the basis of the National Chlamydia Screening Programme (NCSP), although this is not a whole population screening programme.

The scheme is aimed at 15-24 year olds, who make up 12% of the population but who account for almost 65% of the incidence of chlamydia. Each primary care trust (PCT) has been given increasing targets for screening of 15-24 year olds every year after the launch of the NCSP in 2003, rising from 7% to the target for this year of 35%. Positivity rates have varied since its inception and for the first three quarters of 2010/11, rates were 5.4%, compared to the positivity rate of 7.3% in 2008/9.

The aims of the NCSP are to:

  • Prevent and control chlamydia through early detection and treatment of asymptomatic infection.
  • Reduce onward transmission to sexual partners.
  • Prevent the consequences of untreated infection.

The NCSP would like to see chlamydia screening embedded into core services, including general practice, pharmacies, termination of pregnancy services and sexual health clinics.
The majority of the population do not have any signs or symptoms, and for those people who do, this could indicate a chronic infection or a complicated case of chlamydia involving the upper genital tract. Box 1 shows the main signs and symptoms along with the percentage of those who are asymptomatic.

[[Box 1. Chlamydia]]

Given the high percentage of people without any symptoms, it is important that prompt detection of the infection is made so that treatment can be given and contact tracing of current and previous sexual partners can be commenced. Taking samples for testing can be easy and non-invasive. The advent of the screening programme was based upon having samples that were easy to obtain and non-invasive; this resulted in many microbiology laboratories investing in testing platforms that could process urine samples.

Urine should not have been passed for one hour before taking the sample and, for some testing platforms, the recommended time is extended to two hours. In cases where urine has been passed in the preceding hour, a swab is the alternative, which should be urethral for men and vulvo-vaginal for asymptomatic women (often self-taken). Self-taken samples should not be offered to women with symptoms as it is important to complete a thorough examination, including direct visualisation of the cervix. In these cases, an endocervical sample should be taken with the swab rotated against the endocervical os (the opening of the cervical canal into the uterus).

During examination, if there is any indication of complexity (including cervical excitation, genital pain in male and female patients and abdominal or pelvic pain), a referral or signposting to the specialist sexual health service (also known as genito-urinary clinics) should be considered. This will ensure that additional testing is completed, including gonorrhoea, trichomonas and blood-borne virus screening (HIV, syphilis, hepatitis B and C). These specialist services are often able to make a diagnosis (though this does not include chlamydia) while the patient is still in the clinic so that prompt treatment and follow-up can be given. This is particularly important for suspected pelvic inflammatory disease (PID) and epididymitis/orchitis.

An important aspect of screening for chlamydia that will contribute to improving the public health of the nation is the rate of contact tracing of partners of those identified as being infected. Contact tracing, or ‘partner notification', is usually completed by health professionals employed within specialist sexual health services and the NCSP, although there may be some staff within primary care settings who have received extra training and have support from their local specialist services to carry out partner notification.

The patient with the original positive screen is known as the ‘index patient' (IP) and information is collected from the IP about their sexual partners. Figure 1 shows how the infection can be tracked through numerous partners by health advisors, who often become good at finding partners from very little information given to them by the original IP.

[[Fig 1. Chlamydia]]

For chlamydia infection the trace period is six months. The IP is given the option of the partner notification being completed by the health advisor or for the patient themselves to inform all their previous partners that they may have a sexually transmitted infection. It is usual to negotiate timescales if the IP chooses to inform his or her partners themselves, as this will then allow the health professional to make contact themselves and invite the partners into services for treatment and full screening should the IP not manage to contact or convince partners to attend clinics.

It is important not to reveal any details about the IP and to encourage partners to attend for treatment and full screening. For chlamydia infections that are diagnosed within primary care and outside of the NCSP, local arrangements are likely to be in place for partner notification to be completed. In many cases the details are passed to those working within specialist services.

Treatment for uncomplicated genital chlamydia is very effective, but it must be remembered that, without contact tracing, treatment can be rendered useless, as sharing of the infection will continue if partners are not treated.

The firstline choice for uncomplicated genital chlamydia infection is azithromycin 1 g oral stat dose, with advice about abstaining from sexual contact (includes penetrative as well as non-penetrative sex) for seven days until the treatment time has been completed. It is good practice, wherever possible, to treat current partners at the same time as the index patient as this can increase compliance with advice.

Doxycycline 100 mg oral bd for seven days is an alternative but there can be compliance issues with this regimen, which is why azithromycin is the first choice. For patients who may be pregnant/breastfeeding the alternatives are erythromycin 500 mg oral bd for 10 days or amoxycillin 500 mg oral tds for seven days. Azithromycin can be considered for use in pregnancy/breastfeeding but it must be acknowledged that this is ‘off licence'.

Test of cure is not routinely required, except for pregnant patients (six weeks after treatment) and in any patient where there have been compliance issues (vomiting after dose; did not fully comply with doxycycline; or did not follow the advice to abstain from sexual contact).

Patients using oral hormonal contraception no longer need to use an alternative method of contraception during or after treatment with these antibiotics as this advice has now been withdrawn (although this is still the case for rifampicin and rifabutin).4 Any patient with complicated infections should be considered for referral to specialist services where further infection testing will be completed and alternative treatment regimens given. Treatment for sexually transmitted infections is exempt from payment and this is easily managed within specialist services or dispensing practices but can be more difficult to manage with the use of traditional FP10s, unless there has been some local agreement.

The service managing the treatment should ensure that patients are given verbal and written information about chlamydia infection, the treatment they are receiving, the partner notification process, any follow-up advised (eg, if not compliant with treatment or vomiting after treatment) and the implications of not following advice, including the complications that can occur.

These patients should also be reminded that they have only been tested for chlamydia (unless a full screen has been completed) and not for any other sexually transmitted infection. Best practice would be for all patients with a positive chlamydia screen to be screened for the full range of sexually transmitted infections, such as gonorrhoea, HIV and syphilis.

At every opportunity, when discussing sexual activity the use of effective contraception and barrier methods should be advised. This includes barrier methods for all types of sexual contact: vaginal penetration, rectal penetration, oral sex, foreplay etc. Having a supply of a variety of condoms, lube and dams will help you promote the safer sex activity required to reduce the chance of sharing sexual infections. For areas with a condom distribution scheme, this is also the opportunity to register patients for the scheme (based on local guidelines/ages of participants), including a demonstration of effective condom use and lube to prevent splitting/breakages.
In primary care there are many opportunities where opportunistic screening for chlamydia can be suggested, and not just for the under-25s. Consultations in general practice where chlamydia screening could be considered, within and outside of the NCSP, include the following:

  • Renewal of contraception (oral and long-acting contraceptive methods).
  • Use of condom card distribution schemes.
  • Requests for pregnancy tests.
  • Cervical cytology screening.
  • Women presenting with irregular bleeding at any time of the cycle.
  • Travel advice/vaccinations.
  • Meningitis vaccination for students off to university.

Sexual health displays in waiting areas can prompt patients to ask for screening, and many of the schemes running as part of the NCSP have excellent publicity materials that can form the basis for such displays in surgeries and health centres (see Resource).

Chlamydia trachomatis is a very common infection, which can be treated effectively and prevented in the future through good health promotion advice. Despite the existence of the national screening programme, the incidence of this infection continues to rise. Therefore, it is important for nurses to use a variety of health promotion opportunities to determine risk-taking behaviours and offer interventions to break the cycle. A good awareness of chlamydia, the NCSP and local services to which patients can be signposted can all contribute to a reduction in the incidence of chlamydia in the future.

1.    Health Protection Agency (HPA). Trends in diagnoses of sexually transmitted infections in the UK: update for 2008. London: HPA; 2009.
2.    British Association of Sexual Health and HIV (BASHH). UK National Guideline for the Management of Genital Tract Infection with Chlamydia Trachomatis. London: BASHH; 2010.

National Chlamydia Screening Programme

Further reading
Health Protection Agency (HPA). Diagnosis of Chlamydia Trachomatis: Quick Reference Guide for General Practice. London: BASHH; 2010.

Clinical Effectiveness Unit. Clinical Guidance: Drug Interactions with Hormonal Contraception. London: Faculty of Sexual and Reproductive Healthcare; 2011.