Is there any relation between time to positivity in blood cultures and source of infection in patients with Enterococcus spp. bacteraemia?

Abstract number: 1733_434

Alava J., Ezpeleta C., Ezpeleta G., Cabezas V., Atutxa I., Busto C., Gomez E., Unzaga J., Cisterna R.

Objective: The aim of this study is to know if, like in other bacteraemias, the time between blood culture incubation and growth detection measured by the time to positivity in a continuously monitored system correlates with the source of infection and the outcome of the patient who suffers and enterococcal bacteraemia.

Methods: We performed a retrospective, observational study involving adult inpatients that had Enterococcus spp. bacteraemia between 1 October 2003 and 30 September 2006 at a University hospital. Measurements included time to positivity in initial blood culture series, duration of bacteraemia episode, gender, age, rate of metastatic infection, and outcome.

Results: A total of 38 Enterococcus spp. bacteraemias (>1 positive blood culture result) were reported for patients with ages between 1 day–94 years (median age, 69 years); 5 (13.15%) bacteraemias were associated with endocarditis. The microbiological documentation of the source of infection was achieved only in half of the cases. The mortality rate was 21.8%.

The duration of bacteraemia was 1–47 days (median duration, 8 days; average duration 11.65 days). The time to positivity ranged from 40 minutes to 1 day (median time to positivity, 8.45 h). There was significantly shorter for patients with an endocarditis or catheter related infection, compared with the other sources of bacteraemia (p = 0.05) but no statistical difference was observed when both endovascular sources of infections were compared. Analysis using logistic regression found that a short time to positivity was an independent predictor of an endovascular source of infection but not the outcome of the patient. In fact, all the deaths recorded in this study were non-infection related.

Conclusions: Time to positivity in Enterococcus spp. bacteraemia may provide useful diagnostic information of the source of infection but not prognostic information. Meanwhile due to the reduced number of cases further studies are needed.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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