Early detection of new or novel variants of nosocomial pathogens (such as hospital-acquired methicillin-resistant Staphylococcus aureus) is a public health priority. However, surveillance effort is often limited by financial and practical constraints. Although this is widely recognized, no good evidence base exists to inform the design of efficient hospital-based surveillance systems. We address the key questions of how many and which hospitals should be included in such a surveillance system. Using hospital admissions data from England and The Netherlands, we model the spread of a pathogen among the network of hospitals connected by the movement of patients between them. We show how it is possible to design hospital-based surveillance systems that deliver earlier detection times for reduced effort.

Abstract

Early detection of new or novel variants of nosocomial pathogens is a public health priority. We show that, for healthcare-associated infections that spread between hospitals as a result of patient movements, it is possible to design an effective surveillance system based on a relatively small number of sentinel hospitals. We apply recently developed mathematical models to patient admission data from the national healthcare systems of England and The Netherlands. Relatively short detection times are achieved once 10–20% hospitals are recruited as sentinels and only modest reductions are seen as more hospitals are recruited thereafter. Using a heuristic optimization approach to sentinel selection, the same expected time to detection can be achieved by recruiting approximately half as many hospitals. Our study provides a robust evidence base to underpin the design of an efficient sentinel hospital surveillance system for novel nosocomial pathogens, delivering early detection times for reduced expenditure and effort.