Prophylactic antibiotics and Clostridium difficile infection

Letters to the Editor nail varnish. All the male medical staff had short hair. Eighteen percent of the female medical staff had long hair that was not tied back. The white coat is a well-established symbol of the medical profession. Twenty years ago, most junior hospital doctors wore a white coat while consultants wore suits. In this audit, no qualified doctors were observed in a white coat. Some doctors find white coats hot and uncomfortable, perceive them as a cross-infection risk and associate them with a lack of seniority. A study on white coats and medical students showed that the points of frequent contact, such as the sleeves and pockets, were most likely to be bacteriologically contaminated.1 It was suggested that to prevent their serving as a vector, facilities must be made for frequent laundering of coats. However, even if the white coat remains consigned to history, medical staff need to be aware of the importance of wearing clean and appropriate clothes. Scrubs were worn by medical staff working in the accident and emergency department and the intensive care unit. Scrubs should be colour coded to ensure that they are not mistaken for theatre scrubs, which must not be worn outside the theatre environment. Adequate changing and laundry facilities must also be provided. A previous study showed that neck ties worn by doctors harboured potentially dangerous bacteria.2 The position of the tie at waist level places it at a risk of patient contact, unless a plastic apron or buttoned white coat is worn. Alternatively, the tie can be tucked inside the shirt or pocket, or a tie pin can be used. Similarly, long hair must be tied back to avoid transfer of organisms from patient to patient. Wristwatches can impede effective handwashing and are a potential source of infection. However, medical staff rarely remove these during clinical care. Other potential hazards included stone rings, nail varnish and false nails, all of which were breaches of the uniform policy. Uniform policies should include medical staff and should cover additional relevant items, e.g. white coats, scrubs and ties. Clothing, including white coats and ward scrubs, must be laundered daily. During clinical care, ties must be tucked in or a tie pin used. A single plain band ring can be worn, but special care with handwashing is essential. Wristwatches must be removed when undertaking clinical care.

References 1. Loh W, Ng VV, Holton J. Bacterial flora on the white coats of medical students. J Hosp Infect 2000;45:65e68.

93 2. Nurkin S. Is the clinician’s necktie a potential fomite for hospitalacquired infections? Paper read at 104th Meeting of American Society for Microbiology, New Orleans, LA, 23e27 May 2004.

S. Sundeep* K.D. Allen Department of Microbiology, Whiston Hospital, Prescot, UK E-mail address: [email protected] Available online 10 July 2006

* Corresponding author. Address: Department of Microbiology, Whiston Hospital, Dragon Lane, Prescot L35 5DR UK. Tel.: þ44 151 449 0181; fax: þ44 151 430 1824. ª 2006 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhin.2006.04.016

Prophylactic antibiotics and Clostridium difficile infection

Madam, Clostridium difficile is a common hospital-acquired infection and is a significant cause of morbidity and even mortality of inpatients, especially the elderly. C. difficile-associated disease leads to increased hospital stay, the requirement of isolation and more intensive nursing care. For these reasons, it poses a significant financial burden with an attributable cost of £4000 per case in 1996.1 Key stages in the pathogenesis of C. difficilemediated diarrhoea and colitis include removal of colonization resistance, classically by prior administration of antibiotics, with subsequent colonization by toxigenic C. difficile, often through exposure in the hospital environment. A recent study from Sweden demonstrated a significant correlation between the duration of antibiotic therapy and the likelihood of development of antibioticassociated diarrhoea.2 Cephalosporins are known to be associated with a particularly high risk for subsequent development of C. difficile-associated diarrhoea. The Southampton General Hospital Surgical Directorate treats over 10 000 patients per year. Recent audits in our department suggested a possible increase in the number of C. difficile infections, particularly on two wards treating

94 patients who had upper and lower gastrointestinal pathology. Cases of C. difficile infection included both elective and emergency admissions. We conducted a retrospective analysis of all cases of C. difficile infection on these two wards during two different three-month periods in 2004 and 2005 (AugusteOctober 2004 and Junee August 2005). Patient notes from these two wards were searched for details of the surgical procedure performed (emergency or elective), details of antibiotic use including rationale for prescription (i.e. prophylactic or therapeutic), and the subsequent development of C. difficile infection. We analysed the data to look for a relationship between these variables and consequent C. difficile infection. Overall, 28 cases of C. difficile were detected during the two time periods. Of these, 17 cases (60%) were considered to have arisen from prophylactic antibiotic use, with administration of cefuroxime and metronidazole in most cases, and the rest were due to therapeutic antibiotics. Of the prophylactic subgroup, 11 (65%) were found to have received more than three doses of prophylactic antibiotics perioperatively. Figure 1 demonstrates the relationship between the number of prophylactic antibiotic doses administered to patients undergoing elective surgery, and the number of cases of C. difficile infection that followed. It illustrates a clear association between more than three doses of prophylactic antibiotics and development of C. difficile infection. There was no relationship between the type of procedure performed or the type of ward on which the patient was managed. Although this audit was small, the results correlate with those of the Swedish study. While the Swedish study demonstrated a relationship

Letters to the Editor with antibiotic use in general, our finding is specific to the relationship between the number of prophylactic antibiotic doses and development of C. difficile infection.2 Prolonged prophylactic antibiotic use beyond 24 h is not justified in gastrointestinal surgery and often occurs though inadvertent extended prescription.3 This study shows the clear dangers of lack of rigour in controlling the duration of prophylactic antibiotic use. Any arguments put forward for extending prophylaxis must take account of the risk of an increase in C. difficile infection.

Acknowledgements The authors would like to thank Ms Glynis Butcher for her kind assistance in providing case notes for analysis.

References 1. Wilcox MH, Cunniffe JG, Trundle C, Redpath C. Financial burden of hospital-acquired Clostridium difficile infection. J Hosp Infect 1996;34:23e30. 2. Wistrom J, Norrby SR, Myrhe EB, et al. Frequency of antibiotic-associated diarrhoea in 2462 antibiotic-treated hospitalised patients: a prospective study. J Antimicrob Chemother 2001;47:43e50. 3. SIGN. Antibiotic prophylaxis in surgery. Publication Number 45. Scottish Intercollegiate Guidelines Network; 2000.

S. Mukhtara,* H. Shakera A. Basarabb J.P. Byrnec a Directorate of Medicine and Elderly Care, Southampton General Hospital, Southampton, UK b Department of Microbiology, Southampton General Hospital, Southampton, UK c Surgical Directorate, Southampton General Hospital, Southampton, UK E-mail address: [email protected] Available online 24 July 2006

* Corresponding author. Address: Southampton University Hospitals Trust, Tremona Road, Southampton SO16 6YD, UK. Tel.: þ44 07888701571.

Figure 1 Graph illustrating the relationship between the number of prophylactic antibiotic doses and the number of patients with Clostridium difficile infection (P < 0.001, Chi-squared analysis).

ª 2006 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhin.2006.05.006