General practice makes an important contribution to the diagnosis and management of chlamydia and gonorrhoea infections in England, a population-based study has found. However, although most patients diagnosed with chlamydia were managed appropriately, many patients with gonorrhoea were treated with antimicrobials that are no longer recommended.

Patients aged 12 to 90 years, between January 2000 and December 2011, were included for analysis from Clinical Practice Research Datalink (CPRD) records. National surveillance data on patients attending GUM clinics in England in the same period were used for settings outside primary care.

The main findings are summarised in table 1.

The proportion of GP-diagnosed episodes of chlamydia treated in general practice rose from 59.5% in 2000 to 78.5% in 2011. Over 90% were treated with first-line antibiotics as recommended by the British Association for Sexual Health and HIV. Only 3% of all chlamydia episodes had a referral coded.

On average, 40% of episodes of gonorrhoea diagnosed in general practice were treated in primary care during the study period, with a peak of 51.9% in 2008. Overall, 63% of episodes were referred to GUM.

Of those gonorrhoea cases treated in general practice:

• 40% of patients had the recommended regimen

• Ciprofloxacin was the most commonly prescribed antibiotic (41% of treated episodes) and continued to be so when national treatment guidelines changed in favour of cephalosporins in 2005. It had decreased from 42% of prescriptions in 2006 to 20% in 2011

• Cefixime and ceftriaxone were increasingly prescribed from 2005, and by 2011 they were the most commonly prescribed antibiotics (35%)

• Non-recommended regimens prescribed included: doxycycline, azithromycin, and other macrolides and penicillin

Although more infections are being diagnosed in primary care, there is evidence that a significant proportion of those diagnosed with gonorrhoea were given antimicrobials that were not recommended in the national guidelines.

There also appears to be a reduction in the proportion of chlamydia cases diagnosed in general practice relative to GUM and by the NCSP; this might have coincided with scaling up of the NCSP from 2003 to 2008, with more  cases diagnosed in community-based contraception and sexual health clinics.

Dual chlamydia and gonorrhoea nucleic acid amplification tests (NAATs) have been introduced in recent years. While these may improve the detection of both infections, the positive predictive value of these tests is low for gonorrhoea because of its lower prevalence relative to chlamydia. Hence, confirmatory tests and referral to GUM is usually recommended.

The study suggests that while it is clear general practice has been making important contributions to controlling STIs, it emphasises the importance of training for non-specialists in managing STIs especially in the era of antimicrobial resistance.

Dr Richard Ma