In the recent edition (June 2009) of Anaesthesia Whittington et al describe a small workplace audit concerning the bacterial contamination of stethoscopes on their ICU in comparison with similar contamination of personal stethoscopes, and the investigation of current hospital practice with regards to decontamination.

I wish to draw to the authors’ attention to an error in the results. From the raw data, the authors actually demonstrate that 95% of all personal stethoscopes examined (n = 22) and 67% of ICU stethoscopes (n = 24) were colonised with bacteria; in contrast to the 67% of personal and 95% of ICU stethoscopes as published. The authors have made a further error with regards to the percentage of stethoscopes contaminated with potentially pathogenic organisms: 13.6% of personal and 8% of ICU stethoscopes were actually contaminated in contrast to that published. In my opinion, this error reveals more alarming data and implications for all healthcare providers using personal stethoscopes.

In addition, I found the methodology, with regards to the taking of swabs for culture, a little vague. It would be worth knowing whether one swab was used to sample both the diaphragm and bell, which are in effect two distinct areas (the bell being used much less frequently) and in my opinion should be sampled separately. Given that stethoscope cleaning is inconsistently performed, particularly amongst doctors, it would have been of interest to note to which group of health professionals those personal stethoscopes contaminated with pathogenic bacteria belonged.

Thank you for inviting us to respond to the letter of Dr Fauzia Hasnie referring to our paper 'Bacterial contamination of stethoscopes in the intensive care unit'. We are grateful for the interest shown in our paper and in terms of the points raised, the correspondent is correct in pointing out an inconsistency between the text of the Results section and the data presented in the Table 2. The data in the Table are correct and we have inadvertently transposed 'personal stethoscopes' and 'ICU bedside stethoscopes' throughout the sub-paragraph headed Diaphragms, which should read: 'The diaphragms of 67% of ICU bedside stethoscopes and 95% of personal stethoscopes were colonised with bacteria, however these were infrequently pathogenic with 8% of ICU bedside stethoscopes compared to 14% of personal stethoscopes carrying pathogenic organisms'.

This unfortunate error occurred during re-drafting of the paper for clarity, and subsequently escaped surveillance. We are grateful to the correspondent for identifying this error, which does not have any impact on the overall message of our paper, and as the correspondent points out, if anything strengthens the argument.

On conducting a full review of the original data, we have identified a further minor typographical error. In the Results paragraph headed Method of cleaning, the text should read '28 of the 44 questioned', again the data in the Table (Table 1) are correct.

With regard to the other points raised, one swab was used to sample both bell and diaphragm, with a separate swab used for ear pieces. We concluded that, although conceivably the diaphragm may pose a greater risk of contaminating patients, users’ hands were likely to be contaminated by either bell or diaphragm; thus we felt the costs of the additional cultures which would have been required was not justified.

As the samples of individual professional groups were small and not necessarily representative and we had limited space, we did not include the professional identities of the 'owners' of the personal stethoscopes. For completeness we reproduce them here:

Diagphragm

PS7 (Physiotherpist)

PS12 (Surgical SHO)

PS 22 (ICU Spr)

Ear Pieces

PS2 (Physiotherapist)

PS11 (Medical Student)

PS12 (Surgical SHO)

PS20 (Medical SHO)

PS21 (ICU Consultant)

We apologise to the Editor-in-Chief and readers for any confusion these unfortunate errors may have caused, but trust they will not have clouded understanding of our observations and their important implications.