Authors response

Dr Richard Smith
BMJ Editorial Office
 
 

Dear Dr Smith,

Re: Paper : Antibiotic susceptibility of streptococci and related genera causing endocarditis in the UK, January 1996-March 2000.

WORD COUNT: 605

STUDY GUARANTEED BY: Dr Alan P. Johnson
 

With regard to the Editor’s and referee’s comments, which we found constructive, we wish to make the following response:

1. We have modified the title to include the design of the study
2. As the paper now comprises a short report, the abstract is no longer included.
3. As suggested, the Table has been modified to indicate which species of streptococci are included in the ‘viridans’ group.
4. As suggested we have indicated in the text the proportion of cases of endocarditis where isolates are referred to the Reference Laboratory. We would like to stress that we included only confirmed cases of endocarditis in our analysis. In all instances where isolates were from ‘suspected’ or ‘possible’ cases of endocarditis, the hospitals concerned were contacted for information on the final clinical diagnosis. Virtually all of the hospitals contacted co-operated in providing us with the required information. We have not included this information in the revised version of our paper due to the restriction on its length.
5. With regard to the question of bias, our experience is that hospitals rarely indicate that they are referring an isolate because of suspected resistance to penicillin. We believe that the primary reason for sending isolates is that most hospital microbiology laboratories undertake susceptibility using the disc diffusion method (which is a qualitative test). As endocarditis is a serious clinical condition, many laboratories wish to supplement their results with the quantitative data (i.e. MIC values) that we, as a Reference Laboratory, routinely provide.
6. While we agree that non-microbiologist readers might find information on less familiar species to be of interest, we were unable to include this (minor) topic due to restrictions on the length of the paper.
7. As suggested, we have made reference to the work of Dyson et al. (reference 5 in the revised version) who have published interesting work on endocarditis in Wales.
8. As suggested, we have made reference to the limitations of the study in the discussion. We were pleased to note that the referee felt that a prospective study of endocarditis would be of value as were had already decided on such a course of action.