Endoscopes and Lumened Instruments: New Studies Highlight Persistent Contamination Risks

Endoscopy at the hospital. Doctor holding endoscope before gastroscopy

(Adobe Stock by romaset)

Issues with endoscopes and lumened surgical instruments are nothing new to infection prevention and control (IPC) professionals. For years, we’ve seen outbreaks, recalls, and redesigns, yet the risks never seem to disappear completely. Recently, 2 new studies published in The Journal of Hospital Infection (JHI) and American Journal of Infection Control (AJIC) shine a light on some alarming findings, reminding us why vigilance in reprocessing these devices is still crucial.

Endoscope-Linked Outbreak in Germany

The first study, published in The Journal of Hospital Infection, details an outbreak of OXA-181 carbapenemase-producing Klebsiella pneumoniae at a hospital in Mecklenburg-Western Pomerania, Germany. In the initial phase of the outbreak, 19 patients were affected, and 16 had undergone endoscopic procedures. Investigators eventually traced the bacteria to a contaminated colonoscope. In response, the hospital took a drastic step—they replaced all old endoscopes (greater than 10 years old) with brand-new ones.

Problem solved, right? Not quite. Even with new scopes, contamination persisted. In follow-up testing, 4 out of 67 newly reprocessed endoscopes still harbored bacteria, including a gastroscope that tested positive for the outbreak strain. When researchers dismantled some of the scopes, they found cracks, wear, and biofilm formation, along with tolerance to peracetic acid (PAA)—the very disinfectant used for reprocessing.

This study drives home a key point: Replacing old scopes isn’t a magic fix if reprocessing issues and biofilm formation persist. Even brand-new equipment isn’t immune to contamination risks.

AJIC Study: Cleaning Challenges with Lumened Surgical Instruments

The second study in AJIC, led by Cori Ofstead, MSPH, a well-known expert in this field, takes a deep dive into lumened surgical instruments used in orthopedic; neurologic; and ear, nose, and throat procedures. The research team inspected 117 instruments across 40 different types using a borescope—an inspection tool that lets you see inside hard-to-reach places.

What they found was shocking but, sadly, not surprising. Every single instrument had visible debris, rust, or soil, even after cleaning. Brown and rust-colored patches were present in 95% of the instruments, and 73% contained lint or brush bristles. Many of the instruments had design features that physically blocked access for cleaning brushes, making proper decontamination nearly impossible. Even when technicians followed the manufacturer’s instructions for use (IFU) perfectly, contamination still remained.

That last point is especially frustrating. In IPC, we often assume that if we stick to the manufacturers’ instructions for use (IFUs), we’re doing everything “by the book.” But what happens when the book itself is flawed? The authors didn’t just identify problems—they also provided solutions. One key takeaway was that hospitals should send contaminated instruments back to manufacturers and push for real-world testing. IFUs should reflect the actual conditions of sterile processing departments, not just ideal lab settings.

The Takeaway: IFUs Aren’t Gospel—Stay Vigilant

Both studies reinforce a hard truth in infection prevention: just because you’re following the IFU doesn’t mean your instruments are actually clean. We need to stay skeptical, keep testing, and push for better design and oversight.

For infection preventionists, the message is clear: keep an eye on your scopes and lumened instruments. Question the status quo. If these studies show us anything, it’s that contamination can persist despite our best efforts—so we need to be relentless in the fight against it.