Staph Outbreaks Due to Single-Dose Vial Misuse: The Consequences of U.S.P. Nonadherence

The CDC has reported that outbreaks of invasive Staphylococcus aureus infection have been confirmed in 10 patients in two outpatient clinics in Arizona and Delaware due to the use of single-dose or single-use vials (SDV) for more than one patient. These outbreaks are a reminder of the serious consequences that can result when healthcare professionals do not adhere to standard precautions and use SDVs for more than one patient. If SDVs must be used for more than one patient, full adherence to U.S. Pharmacopeia standards is critical to minimize the risks of multipatient use.


  • The safest option remains dedicating SDVs to individual patients.
  • U.S. Pharmacopeia standards of SDV use for multiple patients in clinical settings:
    • withdraw contents into a new sterile syringe in an aseptic manner
    • promptly use the contents for a single patient during a single procedure
    • dispose of the vial and any remaining contents
  • When individually packaged and appropriately sized SDVs are unavailable, qualified healthcare personnel may repackage medication from a previously unopened SDV into multiple single-use vehicles (vials or syringes) 
    • This must be performed using a laminar-flow hood in accordance with standards in U.S. Pharmacopeia General Chapter 797 (Pharmaceutical Compounding — Sterile Preparations)

Pain Management Clinic- Arizona

  • On April 8, 2012, three patients were admitted to a local hospital for treatment of severe infections, including acute mediastinitis, bacterial meningitis, epidural abscess, and sepsis.  They were later culture-confirmed with invasive methicillin-resistant Staphylococcus aureus (MRSA) infections. A fourth patient was found deceased at home six days following treatment at the clinic. The cause of death was reported as multiple-drug overdose; however, invasive MRSA infection could not be ruled out.
  • All four patients had received pain injections on the same day from the same pain management clinic. Ten persons, including the MRSA-infected patients, received contrast injections for radiologic imaging to guide medication needle placement.
  • Clinic staff members typically prepared contrast medium in the patient procedure room, before the arrival of patients; two new syringes were used to withdraw 5mL each from a 10mL SDV of contrast medium (300mgl/mL) and a 10mL SDV of saline solution. The contents from each syringe then were transferred to the alternate vial, resulting in two 10 mL vials of diluted contrast solution, one for use in the morning and one reserved for the afternoon. Among patients receiving contrast on the day of the outbreak, six received injections from the morning vial and four from the afternoon vial. All of the patients with MRSA infections received diluted contrast from the afternoon vial.
  • In addition to identifying improper reuse of SDVs for more than one patient, county health officials also noted that healthcare personnel did not adhere to Standard Precautions because they failed to wear face masks when performing spinal injections

Orthopedic Clinic- Delaware

  • On March 19, 2012, seven patients were admitted to a hospital with evidence of septic arthritis or bursitis. Cultures of fluids from the affected areas (knee, hip, ankle, and thumb) indicated positive MRSA infections. All seven patients had received joint injections from the same outpatient clinic during March 6–8. Of the seven patients with S. aureus infections, five received their injections on the same day. Three additional patients who received injections during March 6–8 developed symptoms that suggested an infection but did not have cultures taken and were treated with oral antibiotics on an outpatient basis.
  • Following a national shortage of the 10mL SDV of bupivacaine, staff members of the clinic began using 30mL SDV of bupivacaine for multiple patients. Only one 30mL vial would be opened at a time, and be accessed over several hours for multiple patients until all contents were withdrawn. Occasionally, an opened 30mL vial would be stored in a medical cabinet for use the next day.
  • As part of the investigation, nasal swabs were collected from the three clinic medical providers and four ancillary staff members who were involved with the preparation or administration of injections. Two staff members whose responsibilities included preparing injections were colonized with S. aureus; one had a strain that was indistinguishable from the outbreak strain.

U.S. Pharmacopeia standards for the use of SDVs in multiple patients can be found in the CDC’s MMWR for July 13, 2012. (Link to