Hughes Helen

Syndromic surveillance is the real-time collection and interpretation of data to allow the early identification of public health threats and their impact, enabling public health action. Statistical methods are used in syndromic surveillance to identify when the activity of indicator ‘signals’ have significantly increased. A wide range of techniques have been applied to syndromic data internationally. As part of the preparation for the 2012 Olympics Public Health England expanded its syndromic surveillance service. As new syndromic systems were introduced, statistical methods were developed and applied for each system, tailored to the particular system challenges at the time, e.g. a lack of historical data, and regular changes to geographical coverage.

Objective

This paper describes the design and application of a new statistical method for real-time syndromic surveillance, used by Public Health England.

Within the UK, previous syndromic surveillance studies have used statistical estimation to describe the activity of respiratory pathogens. The Emergency Department Syndromic Surveillance System (EDSSS) was initially developed in preparation of the London 2012 Olympic and Paralympic Games and has continued as a standard surveillance system, with expanding coverage across England and Northern Ireland. All reporting to this system is completely passive, with no extra work required within the ED. The data collection includes the diagnosis for each attendance, where available, using the coding system in use locally. The coding varies by ED with ICD- 10, Snomed-CT and the less detailed NHS Accident and Emergency Diagnosis Tables all in use. The use of diagnosis coding systems with differing levels of detail creates the need to have a variety of syndromic indicators to make best use of the data received.

We aim to describe the trends in respiratory attendances, and their comparison to the known circulating pathogens identified though laboratory surveillance to establish if any single syndromic indicator may be attributed to any one pathogen in particular. We also aim to describe the flexibility in the development of EDSSS syndromic indicators to best fit the data received.

Objective

Can syndromic surveillance using standard emergency department data collected using automated daily extraction be used to describe and alert the onset of the seasonal activity of named respiratory pathogens within the community?

We assessed the impact of the London 2012 Olympic and Paralympic Games on syndromic surveillance systems including the incidence of syndromic indictors and total contacts with health care.

Introduction

Mass gatherings can impact on the health of the public including importation of infectious diseases, exposure of international visitors to endemic diseases in the host country and the increased risk of bioterrorist activity. Public health surveillance during mass gatherings therefore affords an opportunity to identify, and quantify any impact (or reassure on the absence of impact) on public health in a timely manner. In preparation for the Games, Public Health England undertook a programme of work to expand the existing suite of syndromic surveillance systems to include daily general practitioner out of hours (GPOOH) consultations and emergency department (ED) attendances at sentinel sites. These new systems complemented existing syndromic surveillance systems offering the opportunity to monitor trends in patient contacts with GPs outside of normal day time opening hours, as well as potentially the more severe end of the disease spectrum which would present at EDs. We assessed the impact of the 2012 Olympics on national surveillance systems, comparing to periods before and after the Games and in previous years and also the impact of specific events during the Games.

Public Health England has developed a suite of syndromic surveillance systems, collecting data from a number of health care sources, and linking to public health action to try and improve the public health benefit of the surveillance.1 We aim to describe this national syndromic service, highlighting the flexibility of the systems in responding to a range of environmental incidents.

Objective

To deliver a national syndromic surveillance service, linking analytical and statistical methods with public health action to provide surveillance support for national public health programmes monitoring the spread of infectious diseases and the health impact of environmental incidents in England.

Syndromic surveillance systems are used by Public Health England (PHE) to detect changes in health care activity that are indicative of potential threats to public health. By providing early warning and situational awareness, these systems play a key role in supporting infectious disease surveillance programmes, decision making and supporting public health interventions. In order to improve the identification of unusual activity, we created new baselines to model seasonally expected activity in the absence of outbreaks or other incidents. Although historical data could be used to model seasonality, changes due to public health interventions or working practices affected comparability. Specific examples of these changes included a major change in the way telehealth services were provided in England and the rotavirus vaccination programme introduced in July 2013 that changed the seasonality of gastrointestinal consultations. Therefore, we needed to incorporate these temporal changes in our baselines.

Objective

To improve the ability of syndromic surveillance systems to detect unusual events.

The impact of poor air quality (AQ) on human health is a global issue, with periods of poor AQ known to occur in multiple locations, across different countries at, or around the same time. The Public Health England (PHE) Emergency Department Syndromic Surveillance System (EDSSS) is a public health legacy of the London 2012 Olympic and Paralympic Games, monitoring anonymised daily attendance data in near real-time from a sentinel network of up to 38 EDs across England and Northern Ireland during 2014. The Organisation de la Surveillance COordonnée des URgences (OSCOUR®) is a similar ED system coordinated by Santé publique France and has been running in France since 2004, established following a major heatwave in 2003 to improve real-time public health surveillance capabilities. This truly national network included around 540 EDs in 2014.

Objective

To assess the impact on human health observed in association with periods of poor air quality which extended across international borders, affecting both London (UK) and Paris (France). In particular to quantify increased levels of emergency department (ED) attendances for asthma and wheeze/ difficulty breathing, and how different age groups were affected. Here, using ED syndromic surveillance from England and France, we aimed to identify and describe the acute impact of periods of particularly poor air quality during 2014 on human health in both London and Paris.