Characterisation of invasive group B streptococci from adults in Denmark 1999 to 2004

Abstract

The aim of this study was to characterise the GBS isolates causing severe invasive infections in patients (>15 years) in Denmark from 1999 to 2004. Methods: 411 invasive GBS isolates were phenotypically characterised by CPS serotype and protein Cα, Cβ and R4. Results: The incidence of invasive GBS disease ranged from 2.2 to 3.2 per 100,000 adults in the study period, being highest among adults above 65 years of age. Diabetes was observed in 15% of the cases, 12% had alcohol abuse and 7% had cancer. Of all isolates 77% were CPS serotypes Ia, Ib, III or V. The surface proteins Cα or R4 were detected as the only protein in 57% of the GBS isolates. Cβ was detected in 12% of the isolates, but always in combination with either Cα or both Cα and R4. Conclusions: The incidence of invasive GBS infections continued to increase in Denmark from 1999 to 2004. In that period, the overall case fatality was 14%. The most prevalent CPS serotypes were serotypes III, Ia, V and Ib. The most prevalent surface protein was R4 when testing for R4, Cα, Cβ. There was no clear relation between the GBS phenotype and infections with fatal outcome. Based on the comments from the reviewers we have revised our manuscript. In the revised manuscript the changes are inserted with Microsoft words track changes. These revisions are also specified below. Reviewers' comments:#Reviewer #1: The seasonal data do not appear to be significant -the authors should not speculate on insignificant data.# Answer: We agree with reviewer and have therefore deleted figure 1 and only writ-ten in the text, that we observed a seasonal tendency (see page 6. line 22-25 and page 10, line 10-12). Because of this figrure numbers for the remaining two figures have been changed thoughout the manuscript.#Reviewer #1:This is a major problem in the discussion of the mortality data -this database should be used to do a multivariate analysis of the associations -both clinical and serotype -that appear to predict mortality -the authors can then specu-late on any significant associations -at the moment the speculations seem to be based on % differences which is inadequate.# Answer: The main focus of this study was typing of the invasive GBS isolates from adults in Denmark. Thus as we also had information on fatal or not fatal out-come of the GBS infection and some information on the patients clinical conditions we found it relevant to add this information even though that it is impossible to make statistical significant conclusions as the study is too small for this. However to make it clear for the reader, that the added clinical information is of limit character, we have added several sentences to the manuscript to emphasis this. We have added the sentence on page 12 line 19-20: "however the number of isolates belonging to each CPS serotype from fatal cases was too low to make clear conclusions" and on page 13, line 2-3: "however the number of isolates belonging to each protein serotype from fatal cases was too low to make clear conclusions". We have also added a sente...

Dominance of Serotype Ia among Group B Streptococci Causing Invasive Infections in Nonpregnant Adults in Portugal

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Evaluation of streptococcal toxic shock-like syndrome caused by group B streptococcus in adults in Japan between 2009 and 2013

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Characterization of Invasive Group B Streptococcus Strains from the Greater Toronto Area, Canada

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