Surveillance of infection in hospitals

Abstract

A wide range of activities is loosely described as ‘surveillance of infection’, a term that seems to mean different things to different people. These activities include the observation of the incidence and spread of infection, scrutiny of laboratory isolates, surveys of morbidity and mortality, and even considerations of vaccines, disinfectants and insecticides. Many programmes for the control of hospital-acquired infection include some kind of surveillance activity which is often ill-defined. The word ‘surveillance’ means literally ‘Supervision, close observation . . . especially “under surveillance” not trusted to work or go about unwatched’ (Concise Oxford Dictionary, 5th edition). Thus there is no implicit guarantee that surveillance of infection per se results automatically in prevention or even control. The ubiquity of this false hope is illustrated by the Italian translation of ‘surveillance’ as ‘controllo microbiologico’. Ten years ago, Benenson (1970) usefully clarified the definition of surveillance as ‘the continuing scrutiny of all aspects of occurrence and spread of a disease that are pertinent to eJjCective control’. This more restrictive definition is entirely appropriate, for example, for those activities that led to one of the major achievements of this century, namely the control and ultimate eradication of smallpox. What is less clear is the role of surveillance in the control or prevention of hospital-acquired infection, and few can be unaware of the discrepancies in practice from one hospital to another in the United Kingdom, or between this country and, for example, the United States. Controversial attitudes to surveillance often reflect vested interests in the deployment of financial resources, medico-legal aspects, governmental and political pressures and the survival of elaborate expensive career infrastructures. A critical re-appraisal of the potential and limitations of the surveillance of hospital infection is thus well justified. Surveillance activities must be evaluated against their acclaimed objective, namely the identification of problems which stimulate the initiation of some action that leads to the prevention or control of hospital infection. Since the advent of the Control of Infection Nurse, (CIN) (Gardner, Stamp, Bowgen & Moore, 1962) it has become fashionable in North America and elsewhere to devote increasing resources to gathering information in the wards, which is intended to measure the incidence of hospital-acquired infection on a continuous basis (Haley & Shachtman, 1980). It has become clear to many that such a labourintensive activity usually fails to yield accurate or useful information. Ward registers of infection are usually incomplete, and infection record cards for infected patients or discharge forms have rarely produced reliable data, and the obvious problems of who should complete these records and whether clinical infections,