Pneumococcal bacteraemia: clinical and microbiological epidemiology in Dundee, Scotland

To report the incidence of drug resistant Streptococcus pneumoniae isolated from blood culture in Dundee, Scotland. We shall also review the clinical and laboratory findings in these cases.

A retrospective review was undertaken of all cases of S. pneumoniae bacteraemia identified in our local area during a three year period from August 1st, 1997 to July 31st, 2000 (107 cases.) Data was obtained from patient medical records, blood culture reports and results of Stoke's disk testing. Many organisms were also sent to the Scottish Meningococcus and Pneumococcus Reference Laboratory for serogrouping and determination of the minimum inhibitory concentration of common antibiotics.

Annual incidence of bacteraemia was approximately 15.9-17.8 per 100000 population. Mortality was 33% (34 and 30% for those with pneumonia or meningitis, respectively). No relationship was seen between patient age and overall mortality. Factors relating to increased mortality were a high respiratory rate (p=0.01), high blood urea level (p=0.05) and the presence of confusion (p<0.01) on admission to hospital. The incidence of penicillin resistant S. pneumoniae was 7%, all of these isolates having low level resistance. Macrolide resistance was 8%. Neither were found to be increasing over the three year period. The most common serogroups were 23 (18%) and 14 (12%).

The incidence of penicillin resistant S. pneumoniae isolated from blood culture in Dundee, Scotland, is similar to the UK average and did not appear to be rising between 1997 and 2000.