An outbreak of pseudobacteraemia caused by Burkholderia pickettii: the critical role of an epidemiological link.

A protracted outbreak of pseudobacteraemia caused by Burkholderia pickettii is reported. Initial investigation did not reveal the source of the outbreak. Subsequently, careful examination of patient records provided an insight to the probable source, which was further confirmed by a case control study. It was found that 48% of cases had either hepatobiliary diseases or haematological malignancies, whereas only 15% of the controls had similar problems. Furthermore, a coagulation study was performed on all of the cases on the day the blood culture was taken, but was performed on only 17% of the controls. With the establishment of this epidemiological link, a breakdown in aseptic blood culture technique was suspected. B. pickettii was isolated from citrated bottles used in the wards and from the citrate solution stocked in the haematology laboratory. The clonality of these strains was established by the pulsed-field gel electrophoresis (PFGE) and the arbitrary primed-polymerase chain reaction (AP-PCR). The phlebotomists were notified of the findings of the outbreak investigation, and the importance of strict adherence to the aseptic blood culture technique was re-emphasized.