Identifying outbreaks of sexually transmitted infection: who cares?

The Health Protection Agency (HPA) ranked sexually transmitted infections (STIs), including HIV, among the greatest infectious disease threats facing the United Kingdom (UK) [1]. A network of genitourinary medicine (GUM) clinics, created after the 1916 Veneral Disease Regulations, exists to diagnose, treat and control STIs in the UK. Each year more than 1.5 million new episodes of STIs are seen in GUM clinics[1], although an increasing number are diagnosed in primary care in the UK [2].

STI outbreaks often signify a failure in routine control measures such as partner notification and treatment and warrant an effective public health response. To do so, outbreaks must first be identified. The mainstay of current surveillance of STIs in the UK is a quarterly statistical return (the KC60 form) completed by all GUM clinics [3]. This includes aggregate data on numbers of new patients seen by diagnostic category but is insufficiently detailed or timely for outbreak identification. Data are also available from voluntary laboratory reporting of confirmed STIs, but not all laboratories report, clinical information on cases is often very limited, and subtyping of isolates is not routinely available. This means that recognising possible STI outbreaks depends almost entirely on the alertness of health professionals.

The HPA has published guidelines for the investigation, management and control of acute STI outbreaks [4], indicating that "identification ... of outbreaks can (our italics) be by the local GUM physician, the consultant in communicable disease control, microbiologist, or regional epidemiologist". The objective of this study was to explore knowledge of, and attitudes to, STI outbreak identification and investigation among the aforementioned health professionals.

We conducted a cross-sectional survey in Wales in June 2005. A questionnaire with a prepaid reply envelope, and a reminder letter three weeks later, was sent to all consultants in GUM (n = 11), to all consultants in communicable disease control (CCDC, n = 5), to a consultant microbiologist of each laboratory (n = 14), and to four senior epidemiologists working at the Communicable Disease Surveillance Centre of the National Public Health Service, including the three regional epidemiologists for Wales. We defined an outbreak as an unusual cluster of infections, or as more infections involving the same pathogen than normally expected. The questionnaire asked whether recipients had identified, reported (only GUM physicians and microbiologists) or investigated STI outbreaks ever, and in the previous 12 months. Furthermore, information was solicited about the perceived importance of investigating STI outbreaks, and whether GUM clinics would be allowed to share personal information with staff of the National Public Health Service in outbreak situations on a "need-to-know basis". Data were entered onto an EpiData V3.1 data base and analysed using Stata V8.2. We computed frequencies and proportions for each response category, and stratified responses according to health professional group.

This study suggests that few STI outbreaks are currently recognised in Wales because few health professionals are trying to identify them. Even fewer STI outbreaks get reported to public health authorities and result in a multidisciplinary response. Furthermore, substantial uncertainty exists about confidentiality of patient information in STI outbreak situations. Since surveillance schemes for STIs are similar throughout the UK, it is conceivable that a comparable situation exists in areas of the other UK countries.

To our knowledge, no study has yet addressed the issue of alertness of health professionals to identify STI outbreaks. Of interest, identifying and investigating STI outbreaks is not explicitly mentioned as an objective of STI surveillance schemes in the UK [3].

The control of unrecognised outbreaks and, according to this survey, of some of the recognised outbreaks, is by routine partner notification and treatment only. These interventions, however, are limited in their effectiveness [5]. For example, anonymity of sexual partners, particularly for men who have sex with men [5], and delays in partner notification and treatment [6] (e.g., because of waiting times at GUM services for initial consultation [7], or delayed notification of partners by the index patient) are impediments for timely interruption of onward transmission. A systematic outbreak investigation, usually by a multidisciplinary outbreak control team, can facilitate a multifaceted response to the outbreak that is adapted to the size and circumstances of the incident. This might include, for example, active case finding by prompting awareness among providers and outreach workers, and selective screening of patients with similar or milder clinical presentations. A more network-informed approach could identify central persons in the sexual network (likely to be core group members), and extend case finding efforts to nonsexual contacts of cases [8]. Together with descriptive epidemiology, approaches like this could lead to more complete ascertainment and timelier identification of outbreak cases and their contacts, and a more accurate description of the population at risk. In consequence, earlier treatment and education of a larger number of outbreak-related cases could reduce spread of infection and promote the number of persons that modify their risk-behaviour. Furthermore, the use of analytical epidemiological studies may identify risk factors that allow for a more targeted intervention approach [9].

Although patient confidentiality is a central tenet of GUM practice, the law allows sharing of patient information with other health professionals in the interests of controlling spread[4]. It is noteworthy that only half of the survey respondents thought this was true and should be practiced in STI outbreaks. This indicates not only difficulties for an effective multidisciplinary response to STI outbreaks in many instances, but also that a common conceptual framework of how to cooperate with public health authorities in STI outbreaks does not currently exist in Wales. Clearer definition of roles in STI outbreak identification and control, particularly on the local level, are needed. Setting up of regular sexual health liaison meetings involving GUM physicians, public health officials (e.g., CCDC and public health nurses), and representatives of Local Health Boards may increase mutual understanding and thereby help in defining the roles of these groups – not only in outbreak situations. Furthermore, improved surveillance methods based on individual data with a more timely data flow to regional epidemiologists or to local public health authorities (i.e., the Health Protection Team in the UK) would enable these professionals to identify increases in notification data indicative of STI outbreaks.

This study targeted health professionals across the whole of Wales that might potentially identify STI outbreaks. Yet, the number of survey recipients was small. Extending the study to other UK countries would provide the statistical power to compare among health professions, and possibly reveal regional differences in practice in the UK. This would help in identifying areas where, in particular, STI surveillance efforts need to be strengthened.

Prompt identification and coordinated investigation of outbreaks is central to the control of many infectious diseases. This does not appear to be the case for STIs, which we believe represents a lost opportunity to reduce or even stop transmission. To effectively control STI outbreaks in Wales, and possibly in other countries of the UK, improved surveillance methods based on timely and detailed ascertainment of individual cases are needed, as well as convincing health professionals of the importance of identifying and investigating STI outbreaks.