Bacteraemia in a Portuguese hospital: a 9-year analysis

Abstract number: 903_r1903

Pessanha M.


The aim of this study was to analyse the bacteriaemia rate and evolution of the most frequent microbiological agents isolated at the laboratory of a central hospital in Lisbon, between 1994 and 2002.


We studied 40 039 blood cultures and we analysed the most frequent agents responsible for bacteriaemia. Until 1996, blood cultures were processed with Oxoid blood bottles, manually. Since 1997, BactAlert was introduced and microbiologic identification and susceptibility tests were performed by Vitek system.


From the 40 039 blood cultures we have obtained a positivity rate of 9.7% (3871 bottles) and a contamination rate of 6.3% (2508 bottles).

Coagulase-negative staphylococci were the most frequent isolated agent (mean: 16.3% with a slightly decrease in the last years.

It was followed by methicillin susceptible Staphylococcus aureus (MSSA) (15.6%), which has a tendency to decreased, and E. coli (12.7%) that seems to be increasing. Specially in the last years, it is important to notice the emergence of methicillin-resistant Staphylococcus aureus (MRSA) (8.2%), Enterococcus faecalis (7.3%) and Candida spp (4.8%). Other organisms had a low incidence and their emergence was intermittent (Streptococcus pneumoniae, Klebsiella pneumoniae).


The elevated contamination rate alert us for the importance of a correct sample collection as goal of results quality.

Although Staphylococcus epidermidis is the most commonly isolated agent, as expected, we notice a pattern change in which E. coli is more often isolated and reached the top at 2000 and 2002.

It is also concerning the increasing incidence of MRSA and Enterococcus faecalis.

Since 2001, yeasts started to assume an important role as an etiologic agent as a result of the more and more agressive antimicrobial therapies that are prescribed to the patients.


Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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