The two most recent National Priorities Guidance documents issued by the UK Department of Health have each highlighted the need to control hospital infection if the modernization programme for health services is to be achieved.1,2 The current vision for UK National Health Service (NHS) priority areas includes ‘strengthening services to prevent and control communicable diseases, especially hospital-acquired infection’.2 Infection control in the UK has recently achieved a high priority in the minds of the public, politicians, media and health care workers. Infection control teams (ICTs) must capitalize on this to ensure action rather than rhetoric or ‘wish lists’. Put simply, ICTs must endeavour to secure support and funding which is commensurate with the importance of meeting their objectives. However, without the help of a colleague who has a degree in business administration or economics, how can an ICT develop strong business cases to compete for scarce funds within hospital Trusts? This article aims to highlight the main arguments an ICT can use to strengthen its case for resource allocation. The constantly changing external environment, advancing technology, legislation, the introduction of Clinical Governance and a drive to maximize health care resources have made costing of infection control a management priority. Studies on the costs of hospital-acquired infections (HAIs) have used different methods, definitions and degrees of stringency when calculating indirect costs, and there is therefore still uncertainty over their true economic impact on the community and on the workplace economy (Table I).3,4 Accepting these limitations, an Office of Health Economics’ publication has highlighted the burden attributable to HAIs.4 Interestingly, both this publication4 and the more recent UK National Audit Office (NAO) report5 prompted media headlines that focused on the fact that UK annual deaths due to HAIs (approximately 5000) are more frequent than those due to road traffic accidents.6–8 This figure was an estimate based on US data for the mid-1980s which ranked HAI in the top 10 causes of death.9 Hence, HAI in the UK in 1995 was estimated as the primary cause of, or major contributor to, death in 1% or 3%, respectively, of all fatalities (approximately 5000 and 15 000 deaths, respectively).3 Since the major calculated cost of HAI is usually due to increased length of hospital stay, it is crucial that measurement of this is accurate. Plowman et al. have described the pitfalls of different methods for calculating increased stay.4 Four main options exist. Crude weighting estimates the additional in patient days for those with HAI. The concurrent method relies on expert interpretation of whether or not the additional hospital days are actually due to HAI. The comparative method matches HAI cases with comparable non-infected controls, and is generally the favoured approach. The socioeconomic study referred to below also used modelling based on logistic regression to calculate confidence limits for the estimated increased lengths of stay.10 Extrapolating from a single hospital based study, Plowman et al. calculated that HAI cost the NHS in England £1000 million per annum10, a figure about 10-fold higher than the most recent estimate.11 The study examined approximately 4000 in patients and found that 7.8% of them had developed at least one Author for correspondence: Mark H. Wilcox, Senior Lecturer/Consultant, Department of Microbiology, University of Leeds, Leeds LS2 9JT. Fax: 0113 233 5649. E-mail: markwi@pathology.leeds.ac.uk