An investigation into a multistate outbreak of Serratia marcescens bloodstream infections (BSIs) published in the Archives of Internal Medicine found an association between the BSIs and contamination of prefilled syringes.
An investigation into a multistate outbreak of Serratia marcescens (SM) bloodstream infections (BSIs) published in the Archives of Internal Medicine found an association between the BSIs and contamination of prefilled syringes. The results highlight important issues in medication safety, particularly compliance with FDA requirements, timely communication with public health officials to help identify outbreaks in different areas, pursuing possible product-associated outbreaks indicated by solid epidemiologic data and concurrent use of laboratory data, and the need for careful tracking of medication products, including receiving pharmacies at healthcare facilities.
To determine whether clusters of SM BSIs in several states were caused by contaminated prefilled heparin and isotonic sodium chloride solution (saline) syringes from a single manufacturer, inpatient and outpatient healthcare facilities became part of an outbreak investigation from October 2007 through February 2008. The Centers for Disease Control and Prevention (CDC) and the Texas Dept. of Health Services conducted an on-site investigation at the chemotherapy infusion center where cases of infected patients were first reported. Subsequently, the CDC was notified of an outbreak among patients in Chicago receiving supplies from a home-care company, and of an outbreak at a referral cancer center in another part of Texas. Initial information from these sources helped focus the investigation on heparin syringes from one company, and distribution contact information was obtained for 16 facilities and companies in 4 states. The CDC contacted these recipients about any cases of SM BSIs, and posted inquiries on the CDC's Epidemic Information Exchange and the Emerging Infections Network electronic mail distribution list. State health departments distributed the requests to clinicians who filled out case reports for any affected patients.
SM blood isolates were sent to the CDC. Culture specimens were taken from different lots of prefilled heparin and saline syringes by healthcare facilities and the CDC to analyze for contamination with SM.
CDC laboratory results typed 83 SM blood isolates from 7 states; 70 (84%) of these from 6 of the states were genetically related to the outbreak strain. The company involved finally issued a voluntary national recall that included all of its prefilled syringes in January 2008, and reports of SM BSIs to the CDC decreased dramatically thereafter. FDA inspected the facility where the syringes were produced and found the company not in compliance with FDA's Good Manufacturing Practices and quality system regulations.
Attempts to track specific lots of prefilled syringes were hampered by the number of distributors working with the manufacturer and the healthcare facilities receiving product. Such distributors did not have detailed records of product lot numbers making the recall more challenging. Further, although one company manufactured all syringes, none actually had the company's name on the label. Identification needed to be made by the National Drug Code, a specific number assigned to and displayed on a product, even if it is relabeled. This problem underscores the need for all parties handling medical supplies at healthcare facilities to be aware of this code. Finally the contamination of syringes was probably intermittent, which made it more difficult to identify contaminated syringes on laboratory results alone.
Investigators note limitations, including the likelihood that case numbers are underestimated, an inability to determine why some differences occurred between probable and definite cases (although 84% were definite), and not always being able to assess the exact lots of syringes to which patients had been exposed. Lot numbers prove rarely available in either medical records or pharmacy records; although outpatient pharmacies and home-care companies did often record lot numbers in this case. The authors call on other record keepers to follow this example in order to help quickly identify defective pharmaceuticals "and expedite the recall of these products, potentially averting additional cases."
Blossom D, Noble-Wang J, Su J, et al. Multistate outbreak of Serratia marcescens bloodstream infections caused by contamination of prefilled heparin and isotonic sodium chloride solution syringes. Arch Intern Med. 2009;169:1705-1711.