S Tadiparthi1, K Shokrollahi, A Juma, J Croall. 1. Department of Plastic and Reconstructive Surgery, Countess of Chester Hospital, Chester, UK. tadiparthi@hotmail.co.uk
Abstract
INTRODUCTION: Marker pens are widely used in surgery but pre-operative marking of patients may be a cause of bacterial cross-infection. PATIENTS AND METHODS: Two experiments were performed to assess whether marking pens can be cause of cross-infection: (i) 26 indelible marker pens were collected from surgical wards for analysis; and (ii) 'fresh' as well as 'dry' (artificially dried by removing cap and exposing tip for 2 h) new permanent marker pens, and whiteboard marker pens were inoculated by dipping the tips into various concentrations of methicillin-resistant Staphylococcus aureus (MRSA). Each pen was inoculated onto 2 blood agar plates at 0 (immediately after inoculation) to 30 min at various intervals, 4 h and 24 h. The plates were incubated for 18 h at 35 degrees C in an incubator. RESULTS: Of 26 pens collected from the wards, 2 cultured Micrococci spp. (skin commensals). The constituents of new 'fresh' pen tips rapidly kill MRSA - in all cases by 4 h, but usually within minutes. At high inoculum concentrations, MRSA is not killed immediately. Dry marker pens harbour MRSA for at least 30 min and probably longer. CONCLUSIONS: Marker pens can act as fomites for nosocomial infection. The ethanol-based ink in permanent marker pens has a bactericidal action against MRSA that starts within seconds, and they are likely to be safe to use with a gap of at least 2 min between patients. Usually, harmless skin commensals are not pathogenic except in immunocompromised patients. Old or dried-out marker pens can harbour pathogens and should be discarded before attempted use on patients. We recommend disposable markers for the immunocompromised and patients with a known positive MRSA status.
INTRODUCTION: Marker pens are widely used in surgery but pre-operative marking of patients may be a cause of bacterial cross-infection. PATIENTS AND METHODS: Two experiments were performed to assess whether marking pens can be cause of cross-infection: (i) 26 indelible marker pens were collected from surgical wards for analysis; and (ii) 'fresh' as well as 'dry' (artificially dried by removing cap and exposing tip for 2 h) new permanent marker pens, and whiteboard marker pens were inoculated by dipping the tips into various concentrations of methicillin-resistant Staphylococcus aureus (MRSA). Each pen was inoculated onto 2 blood agar plates at 0 (immediately after inoculation) to 30 min at various intervals, 4 h and 24 h. The plates were incubated for 18 h at 35 degrees C in an incubator. RESULTS: Of 26 pens collected from the wards, 2 cultured Micrococci spp. (skin commensals). The constituents of new 'fresh' pen tips rapidly kill MRSA - in all cases by 4 h, but usually within minutes. At high inoculum concentrations, MRSA is not killed immediately. Dry marker pens harbour MRSA for at least 30 min and probably longer. CONCLUSIONS: Marker pens can act as fomites for nosocomial infection. The ethanol-based ink in permanent marker pens has a bactericidal action against MRSA that starts within seconds, and they are likely to be safe to use with a gap of at least 2 min between patients. Usually, harmless skin commensals are not pathogenic except in immunocompromised patients. Old or dried-out marker pens can harbour pathogens and should be discarded before attempted use on patients. We recommend disposable markers for the immunocompromised and patients with a known positive MRSA status.
Authors: Alicia I Hidron; Ekaterina V Kourbatova; J Sue Halvosa; Bianca J Terrell; Linda K McDougal; Fred C Tenover; Henry M Blumberg; Mark D King Journal: Clin Infect Dis Date: 2005-06-08 Impact factor: 9.079