A recent outbreak involving sterile medical supplies gives insight into a new hospital infectious disease threat.
When you think of healthcare-associated outbreaks, the normal offenders are Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA), etc. Unfortunately, there are other, more sinister organisms that prey upon sterile products, and the high-paced world of healthcare often results in poor practices that leave room for contamination. Burkholderia cepacia (B. cepacia) is one such organism. A complex, Gram-negative aerobic bacilli that is considered “an environmental bug”—meaning that it is often found in soil, plants, and moist areas—this organism tends to be found in medically complex and compromised patients, like those with cystic fibrosis. B. cepacia preys upon patients in Intensive Care Units (ICUs), who are already fighting for their lives.
Although B. cepacia is not a wholly unusual organism in healthcare settings, it’s not one that is typically found in the blood. Outbreaks have involved bloodstream infections, respiratory infections, and the urinary system, but what’s concerning about these outbreaks is their origin. For an environmental organism not frequently found in such invasive body systems, it’s a glaring red flag when we see blood cultures with B. cepacia. These outbreaks point to an increasing trend for this hardy bug; contaminated medicines, medical equipment, or environments. In fact, a recent investigation of an outbreak across hospitals in Queensland, Australia gave insight into how B. cepacia is infiltrating sterile products and the world of healthcare.
Researchers began evaluating cases of hospital-associated B. cepacia bacteremia across 4 hospitals and several patients. Because of previous international outbreaks that involved the contamination of B. cepacia and the invasive nature of the cultures, investigators looked at contaminated medical products and devices as the potential source of the infections.
Point-source investigations involved sequencing and testing of certain objects and products. A total of 11 patient isolates with the same sequence type were identified across 4 hospitals within Australia and this same type was identified in contaminated gel isolates. These findings were a clear indicator what the smoking gun was—the “sterile” gel that was packaged in sachets to be used within sterile ultrasound probe covers.
“The contaminated ultrasound probe cover kits were located within kits packaged for use during central line insertions predominately in the ICU. In testing multiple samples of the gel sachets, it was noted that the sterile gel sachets packed in foil packs within the kits were not consistent and varied in packaging, with different kinds of sachets from kit to kit,” the investigators wrote.
The hospitals immediately pulled these kits from use and notified the company. The investigators also concluded that given the labeling of the packaging, it is likely that contamination of the gel occurred during placement into the foil packets.
Following the conclusion of their investigation, the team noted several issues: increased use of ultrasound guidance for central lines can potentially put patients at risk given this contamination; the potential for contaminated gel to cause bacteremia due to insertion is extremely concerning given the deadly nature of bacteremia and sepsis; and finally, it is crucial to now consider these products in unusual cases of bacteremia.
Overall, this outbreak of healthcare-associated B. cepacia points to the potential for medical equipment and products as transmission mechanisms. Investigators involved in future outbreaks of invasive, healthcare-onset B. cepacia should look outside the realm of the normal offenders and consider products and devices that may be deemed "safe" or sterile.