An Outbreak of Pseudobacteremia Caused by Enterobacter cloacae from a Phlebotomist's Vial of Thrombin

In a 15-day period, seven patients in a small hospital each had one blood culture positive for Enterobacter cloacae. None of the seven patients was septic. All seven positive culture specimens had been obtained by phlebotomist A, who also had obtained 13 negative culture specimens in the same period. Seven other phlebotomists had drawn 69 blood samples for culture during the same period; none had yielded any microorganism (p = 0.00001). Vials of thrombin, routinely used to coagulate blood specimens for chemical analysis, had been carried on the phlebotomy trays. We observed that phlebotomist A occasionally spilled drops of the viscous thrombin on her finger during the procedures. Culture of the thrombin on her tray yielded E. cloacae. No further cases of E. cloacae bacteremia occurred after she stopped drawing blood for culture and the thrombin on her tray was removed from use.