Young age, having sex more than once with the infected partner, and a greater number of partners are all risk factors for chlamydia in contacts, a study from a GUM clinic has shown.

A questionnaire-based, cross-sectional study was carried out using contacts of chlamydia cases attending a GUM clinic in Leicester. Only those who were verified as a contact case and willing to have a chlamydia test were included.

A total of 123 chlamydia contacts were recruited by the health advisor over a six-month period. Of the 115 contacts included in the analysis, 60 (52%) were positive for chlamydia.

The age range was 16 to 64 years, with a mean of 25 for men and 21 for women. Overall 48% were aged 19 to 24.

A multivariate analysis showed that young age, more than one episode of sexual intercourse with the index case and a greater total number of sexual partners were associated with a positive chlamydia result. The findings confirm those of large, population-based studies such as NATSAL 2000 (National Survey of Sexual Attitudes and Lifestyles).

Management of most STIs includes treatment of the index case with appropriate antibiotics, as well as treating their partners to ensure the index case is not re-infected and also to reduce the onward transmission to other partners. This epidemiological treatment is an aspect of partner notification. It forms the protocol for managing partners of infected individuals detected under the National Chlamydia Screening Programme which targets young people aged 16-24.

If positivity remains just under 10% on average across all English PCTs, then a large number of contacts could be treated unnecessarily, representing a waste of resources and possibly encouraging resistant organisms.

This study is too small to trigger any changes to current practice. Larger studies are needed to weigh up the risks and benefits of switching to a policy of offering epidemiological treatment just to high-risk contacts, the researchers conclude.

However, this study helps to reinforce the importance of partner notification as an important tool to reduce onward infection of STIs such as chlamydia. Not only do we need to convey the importance to the index case that their partners need testing and treatment, but we also need to remember to test and treat the partners if they present to us in general practice.

Dr Richard Ma

• Schembri G, Schober G. Risk factors for chlamydial infection in chlamydia contacts: a questionnaire-based study. J Fam Plann Reprod Health Care 2011; 37:10-16.doi:10.1136/jfprhc.2010.0004