14th ICID - Poster Abstracts - International Society for Infectious ...

When citing these abstracts please use the following reference:
Author(s) of abstract. Title of abstract [abstract]. Int J Infect Dis 2010;14S1: Abstract number.
Please note that the official publication of the International Journal of Infectious Diseases 2010, Volume 14, Supplement 1
is available electronically on http://www.sciencedirect.com
Final Abstract Number: 25.001
Session: Clinical Bacterial Infections
Date: Wednesday, March 10, 2010
Time: 12:30-13:30
Room: Poster & Exhibition Area/Ground Level
Type: Poster Presentation
Clinical significance of polymicrobial bacteremial as determined by the pattern of gram stain
M. NORIZUKI, S. YAMAMOTO, N. HOSOKAWA
Kameda Medical Center, Kamogawa, Japan
Background: Polymicrobial bacteremia has been associated in higher mortality in past studies.
The objective of this study was to investigate etiology, source of infection and mortality.
Methods: We retrospectively reviewed microbiological result of blood cultures in 865-bed tertiary
hospital in Japan during the past 22-months ends 31 September 2009. In-hospital mortality, 28-
day mortality, follow up period, site of infection, past medical history, gram stain result of blood
culture (gram positive cluster, gram positive chain, enterobacteriaceae like gram negative rod,
non-fermenting gram negative rod (e.g. P.aeruginosa), gram positive rod and fungi) and
organisms were collected.
Results: Ten-thousand eight hundred thirty-eight blood cultures were taken and 16.3 %
(n=1,771) were positive. Seventeen cases of polymicrobial bacteremia were excluded because of
contamination. There were fifty-one (2.9 % of positive blood culture) episodes of polymicrobial
bacteremia. Four patients were excluded because of admission at the end of investigation. Sixty
percent of patients were male and the average age was 72.7 years. Although over all hospital
mortality was 42.3%(n=20), 28-day mortality was 21%(n=10). The three leading sources of
infection were billiary tract infection (49%), urinary tract infection (15%) and neutropenic fever
(11%). There were 24 cases of hospital acquired infection and 23 cases of community acquired
infection. Hospital acquired polymicrobial bacteremia had higher mortality than community
acquired (63% vs.22%). Enterococcus species (18%), E.Coli (17%) and Klebsiella (15%) were
common pathogens cultured. The hospital mortality was different in combination of organisms.
Three or four organisms were higher mortality than two organisms (57% vs. 36%). The
combination of gram positive coccus and non-fermenting gram negative rod were higher mortality
than gram positive coccus and enterobacteriaceae like gram negative rod (57% vs.27%).
Conclusion: We conclude that polymicrobial bacteremia is an important entity especially in
hospital acquired setting. We were able to predict mortality, prognosis or determination of
contamination from the gram stain result of blood culture.