Skin disease presenting as an outbreak of pseudobacteremia in a laboratoryworker

An outbreak of pseudobacteremia due to Streptococcus pyogenes (group A stre ptococci [GAS]) and methicillin-susceptible Staphylococcus aureus (MSSA) wa s traced to the venting procedure for aerobic bottles prior to their loadin g into the incubator of the BacT/Alert analyzer (Organon Teknika). Bacteria shed by a laboratory worker suffering from impetigo and cellulitis contami nated the aerobic bottles of 10 patients. All blood culture isolates, in ad dition to the isolates from the laboratory worker, were of the same GAS hi and T types, All MSSA isolates from blood cultures and the index case's han ds had the same lytic phage profile. Procedural breakdowns were identified in the laboratory. Bottles were vented outside the biological safety cabine t, gloves were not worn, and unprotected needles were used for the venting procedure. The source of the aspirated bacteria that contaminated the bottl es was identified and the index case was treated promptly.