How new molecular tools can help bugbusters: a Burkholderia cepacia complex outbreak investigation

An outbreak of bloodstream infection (BSI) caused by members of the Burkholderia cepacia complex (Bcc) took place from March 2012 until April 2014 involving thirteen patients. Aim. To describe an outbreak investigation of BSI Bcc and showing how genetic sequencing tools contributed to confirm the hypothesis of extrinsic contamination proposed by an observational study. Methods. The Infection Control Department revised and reinforced good practices of infusion therapy and catheter care, visits to affected wards, a case control study, and environmental screening based on the case-control findings. Results. Data from the case-control study found an association of cases with central venous catheter (OR 1.36; CI 1.15-1.67) and intravenous cisatracurium use (OR 10.75; CI 1.67-68.89). Visits to the operatory block revealed problems related to the cold chain used for the preservation of thermolabile cisatracurium. We could not retrieve Bcc from environmental samples using classic microbiology. New samples from the same surfaces were obtained for genetic sequencing. Bcc was identified in the cooler box, refrigerator and reusable ice packages. Conclusion. Environmental screening using genetic sequencing proved to be a useful tool for confirming our hypothesis of extrinsic contamination raised by the case-control study.