Audit of a network of sexually transmitted infections centred in South Wales

INTRODUCTION

In 2007 we described an HIV network centred in South Wales. ¹ In total, 123 individuals were identified in the network, the majority were men who have sex with men (MSM). Fifteen new cases of HIV were diagnosed. All those traced in the network were informed that they had been in contact with HIV and were given information regarding safe sex practices.

We audited the distribution and frequency of sexually transmitted infections (STIs) within the network, following original identification within it, until July 2008.

METHOD

The original transmission cluster was audited from February 2007 when the index patient was diagnosed with HIV to when the last contact was traced on 6 June 2007. All those diagnosed with HIV in the network as contacts of the index case were interviewed by a sexual health adviser (SHA), partner notification was performed and STI screen was offered and carried out as per national guidelines. ^1–3 A questionnaire detailing the demographic features and sexual history of all those tested was completed at the time of HIV testing in the original cluster by those performing the tests, including number and identifier of sexual contacts given, current STI screens results and high-risk behaviour, i.e. unprotected insertive or receptive anal intercourse in the contact tracing period. ¹ Contacts within the window period three months from the time of exposure to HIV were retested at the end of this time.

All available genitourinary (GU) medicine case-notes of contacts identified in the original cluster were audited from the period February 2007 to 1 July 2008. New diagnoses of HIV, chlamydia, herpes, gonorrhoea, hepatitis, lymphogranuloma venereum (LGV) and syphilis were documented and all new sexual contacts identified by contact tracing (conducted following each episode of a new diagnosis of a STI) were added to the transmission network.

All those traced in the cluster were given information regarding safe sex practices by SHA. Where possible these discussions were structured on the basis of behaviour change theories and aimed to reduce risk taking in line with published guidance. ⁴

RESULTS

In total, 123 individuals were identified in the original cluster in 2007. All were MSMs except for five heterosexual women. Eleven men reported previous diagnosis of HIV. At the time of original identification in the cluster, 15 new cases of HIV and 15 new diagnoses of other significant STIs (gonorrhoea, chlamydia, genital herpes and syphilis) were diagnosed.

Fifty-five GU medicine case-notes were reviewed and 65 new sexual contacts (all MSMs) were added to the cluster, bringing the total number of contacts within the sexual network to 188 by 1 July 2008.

Figure 1a shows the contacts and number of STIs diagnosed during the initial cluster identification period (February 2007 to 6 June 2008) and Figure 1b shows the cumulative known sexual contacts in the network (from February 2007 to 1 July 2008) and number of new STIs diagnosed in patients at subsequent STI screens (not including results of tests conducted on initial identification in the cluster) to 1 July 2008.

OPEN IN VIEWER

Figure 1

(a) Sexual contacts and number of new STIs diagnosed in individuals on initial screening during the original cluster identification period (February 2007 to 6 June 2007). (b) Cumulative known sexual contacts (February 2007 to 1 July 2008) and number of new STIs diagnosed in patients at subsequent screens to 1 July 2008. STI = sexually transmitted infection

There were three new cases of HIV, eight cases of syphilis, eight cases of chlamydia and six of gonorrhoea in 13 contacts. No new cases of LGV, hepatitis or herpes were identified.

Sixteen new diagnoses of significant STIs were made in seven contacts originally identified in the cluster in 2007 (one new case of HIV, six chlamydia, six gonorrhoea and three syphilis diagnoses).

One patient had seven separate diagnoses of STIs.

One of the three new cases of HIV was an individual originally identified in the cluster who tested negative outside of the window period for HIV in 2007.

DISCUSSION

The sexual network described in 2007 has evolved by July 2008, increasing in size with further new diagnoses of STIs. A number of interlinked cliques within the network have the highest risk of STIs, supporting a targeted policy of intervention. Standard interventions in health promotion in the GU medicine setting were not universally successful in preventing high-risk behaviour. Further interventions other than these standard methods applied in the clinic setting are required in those at highest risk.