Two outbreaks of Staphylococcus aureus in Delaware and Arizona occurred when drug shortages led medical staff to re-use single-dose vials for more than one patient, the CDC reported.
The Centers for Disease Control and Prevention discussed the outbreaks in MMWR.
The Arizona Department of Health Services found an outbreak of methicillin-resistant S. aureus (MRSA) stemming from contrast injections for radiologic imaging to guide medication needle placement.
Each morning, clinic staff members diluted the contrast medium and transferred it to vials to use in the morning and the afternoon.
Three patients with resulting MRSA infections were treated for severe infections, including acute mediastinitis, bacterial meningitis, epidural abscess and sepsis. Hospitalizations ranged from 9 to 41 days, with one patient requiring additional long-term acute care. A fourth patient was found dead at home six days after treatment at the clinic. The cause of death was reported as multiple-drug overdose, but the CDC report noted that a MRSA infection could not be ruled out.
Although the contrast medium is manufactured in lower concentrations, the Arizona clinic reported difficulty getting a reliable supply.
In Delaware, the Division of Public Health investigated seven patients hospitalized for septic arthritis or bursitis after receiving bupivacaine from a single-dose vial at an orthopedic clinic. All patients required debridement of the infected sites and intravenous antimicrobial therapy, and were hospitalized from three to eight days.
Of the seven patients with S. aureus infections, five received their injections on the same day. Three more patients developed symptoms that suggested an infection but did not have cultures taken and were treated with oral antibiotics as outpatients.
The orthopedic practice had used 10 mL vials of bupivacaine for single-patient use, but a national drug shortage forced staff to switch to 30 mL vials. Two staffers who had been preparing injections were colonized with S. aureus, and one had a strain that was indistinguishable from the outbreak strain.
"Since 2007, the year that injection safety was included as part of Standard Precautions, 20 outbreaks associated with use of single-dose or single-use medications for more than one patient have been reported," CDC staffers wrote in their report. "These investigations help remind health-care providers of infection prevention practices that are critical for patient safety."