Letters to the Editor 317 screened for MRSA, three sets of swabs are collected at least one hour apart. This reduces the time of strict isolation of patients from five to three days. The change had other advan- tages: it improved the quality of healthcare, and reduced both time-consuming, care protocols and attendant costs. Acknowledgement We would like to thank Constance Bos for her assistance with the laboratory analyses. In 1995 this study won the Dutch Infection Prevention Prize. C.A.J.M. Ballemans* * University Medical A.J.L. Weersink” Centre, H.E.M. Blok* Utrecht, C.M.J.E. Vandenbroucke-Graulst Eijkman- J. VerhoerC Winkler Institute for Microbiology, Infectious Diseases, and Inflammation, Utrecht, The Netherlands fDepartment of Medical Microbiology and Infection Control, University Hospital Vrije Universiteit Amsterdam, Amsterdam, The Netherlands References Beaujean D, Blok H, Weersink A, Verhoef J. Erratum. Long-term methicillin-resistant Staphylococcus aureus (MRSA) carriage and tag- ging of patient records: In Utrecht you’re not MRSA positive for life any more. J Hosp Infect 1997; 39: 83 Neeling AJ, Leeuwen van WJ, Schouls LM et al. Resistance of staphylococci in The Nether- lands: surveillance by an electronic network during 1989-l 995. J Antimicrob Chemotherapy 1998; 41: 93-101 Workingparty Infection Prevention. Manage- ment policy for methicillin-resistant Staphylo- coccus aureus. Guideline no. 35a, January 1995. ISBN 90-73292-18-2 Miller DL, McDonald JC, Jevons MP, Williams REO. Staphylococcal disease and nasal carriage in the Royal Air Force. r Hyg Camb 1962; 60: 451-465 Noble WC, Valkenburg HA, Wolters CHL. Carriage of Staphylococcus aweus in random samples of a normal population. r Hyg Camb 1967; 65: 567-573 Noble WC, Williams REO et al. Some aspects of nasal carriage of staphylococci. J Clin Path 1964; 17: 79-83 Screening for carriage and nosocomial acquisition of Clostridium dificile by culture: a study of 284 admissions of elderly patients to six general hospitals in Wales Sir, I A study was made of carriage on admission and nosocomial acquisition of Clostridium difficile among the elderly admitted to six general hos- pitals in Wales. A total of 284 patients aged 65 years or over admitted to six hospitals were screened for stool carriage of C. difficile on the day of admission and at intervals during their stay. Each hospital was asked to screen a maxi- mum of fifty patients. The hospitals participat- ing were: University Hospital of Wales, Cardiff, Bronglais Hospital, Aberystwyth, Wrexham Maelor Hospital, Wrexham, Withybush Hospital, Haverfordwest, Ysbyty Gwynedd, Bangor, and Glan Clwyd Hospital, Rhyl. Stool samples were examined twice weekly for as long the patient stayed on the ward, up to maximum of seven stools per patient. No correlation of carriage with symp- toms of diarrhoea was sought or recorded. Cultures for C. difficile were made on cefoxitin- cycloserine egg yolk agar (Brazier’s Medium) after alcohol shock treatment of faeces.’ Plates were incubated anaerobically for 48 h and puta- tive isolates of C. difficile were sent to the Public Health Laboratory Service Anaerobe Reference Unit, in Cardiff for confirmation, toxin A and B assay and typing by the modified PCR ribotyping method of O’Neill et aZ.2 Of 0 I999 The Hospital Infection Society