An outbreak of Acinetobacter baumanii in an ICU: effectiveness of an extensive infection control program

Introduction

Acinetobacter baumanii (AB) has been increasingly reported in outbreaks affecting patients from ICUs and other hospital departments. The prevention of the spread of the infection needs exceptional measures in order to prevent transmission to other inpatients through health care workers (HCW). In this study we describe the effectiveness of an extensive infection control program introduced after the onset of an AB outbreak in an ICU.

Methods

The AB outbreak occurred from January 2004 to April 2004 in an eight-bed ICU in a university-affiliated 1800-bed hospital. An infection control policy was instituted to contain the outspread of the infection from mid January (Table 1). In order to analyse the effectiveness of this intervention we have evaluated three periods: the period of AB outbreak (period AB from 1 January to 31 March 2004), the period after AB outbreak (period post-AB from 1 April 2004 to 31 March 2005) and the period before the AB outbreak (period pre-AB from 1 January to 31 December 2003). Statistical analysis was performed with Student's t test, the Mann-Whitney U test and the chi-square test.

Table 1 abstract P2

Results

A total of 855 patients (pre-AB 400, AB 101, post-AB 354) were involved in this study. ICU LOS was higher in period AB (9.99 days in comparison with 7.27 and 7.37 days in period pre-AB and post-AB, respectively) and the mean SAPS II was statistically higher in period AB (43.4) and post-AB (39.2) rather than pre-AB (33.9). The AB outbreak was contained and the pathogen was successfully eradicated from ICU in the remaining time period. No difference in mortality was reported.

Conclusion

The full knowledge of an infection control policy, and its aggressive application, has successfully contained the AB outbreak in a short period of time. It has also prevented the reoccurrence of the pathogen that was completely eradicated from the ICU environment in the following year. The main features of this policy are surveillance cultures, microbiologist consultation and up-to-date antibiotic prescription schemes.