Outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae in an intensive care unit (Brest).

INTRODUCTION

We had for aim to describe control and investigation of an outbreak caused by a strain of Extended spectrum beta-lactamase producing Klebsiella pneumoniae in intensive care units of the Brest teaching hospital.

PATIENTS AND METHOD

The case definition was a patient infected by or carrying the epidemic strain. Control measures and investigations are presented. A case-control study was conducted in the surgical intensive care unit. Each case was matched with two controls based on admission times in the unit. The study focused on diagnostic and therapeutic procedures, and potential contacts with healthcare workers, in this context of cross transmission.

RESULTS

Between February and May 2011, nine cases were reported in the surgical ICU and two in the medical ICU. Eighteen controls were matched with the nine surgical ICU cases. Several factors were found to be statistically associated with infection or colonization by the epidemic strain: the surgical block in which patients had been operated and the ward of first hospitalization; the number of trans-esophageal and trans-thoracic echocardiographies, of central venous catheter insertions, and of surgical operations; intubation. The total number of invasive procedures was also found to be statistically higher among cases.

CONCLUSION

This study identified factors associated with colonization or infection by the epidemic strain. These factors might have been involved in the transmission tree, and be vulnerable elements for the prevention of nosocomial infections and colonisations, and their epidemic spread.