B18021: The second study of infectious intestinal disease in the community - determining disease burden and calibrating national surveillance data in the United Kingdom

Study Duration: April 2006 to September 2009

Contractor: University of Manchester

The public health impact of gastrointestinal infection was underlined by the publication of the Department of Health funded IID (Infectious Intestinal Disease) Study in England by the Food Standards Agency (FSA) in 2000. As well as defining disease burden, a major component of the IID study was calibration of national surveillance systems, in other words, estimation of the factor by which the number of cases of infection with specified pathogens needed to be multiplied to establish the actual number of infections in the community.

The FSA's foodborne disease reduction target has been a major Government public health initiative. Progress is measured using laboratory-report based surveillance data for five key pathogens: salmonellas, campylobacters, Clostridium perfringens, Escherichia coli O157 and Listeria monocytogenes. However, to reflect on recent figures and to measure future progress the FSA will need to know whether or not the relationship between disease burden in the community and official statistics is similar to the situation over a decade ago. Since the original IID Study was undertaken in the mid 1990s, several structural changes have occurred in national surveillance and these might have altered that relationship to a greater or lesser degree. Therefore contemporary information on the relationships in the reporting pyramid is required. To determine this information a second IID study has been commissioned by the FSA and is being undertaken by the University of Manchester in collaboration with the Health Protection Agency (Centre for Infections & Local and Regional Services), Medical Research Council General Practice Research Framework, London School of Hygiene and Tropical Medicine, University of East Anglia, University of Nottingham, Communicable Disease Surveillance Centre Northern Ireland, National Public Health Service in Wales, Health Protection Scotland and NHS Direct.

The main aims of this study are:

• to estimate prospectively the burden and causes of IID in the population and presenting to General Practitioners in the UK and to compare these results with national surveillance data
• to estimate the burden of self-reported IID in each UK nation via a telephone survey and to compare these results with the prospective estimate

Two studies will be conducted in parallel:

A prospective study involving 84 GP practices across the UK using 'future-proof' microbiological techniques and comprising:

• a population cohort study (8400 person-years of follow-up)
• a study of cases of IID presenting to GPs
• a study of routine clinical practice in primary care
• a study to estimate the completeness of reporting to the four national surveillance centres
• a telephone survey (sample size 3, 600 per country)

The study has been designed to be able to detect a 20% decline in severe disease and data will be used to re-calibrate national surveillance data, defining the relationship between disease in the community and official statistics.