The scope about CRE

The USA Today headline read, "Deadly bacteria on medical scopes trigger infection". CNN reported, "What is CRE? Nightmare bacteria have killed again". The news was alarming, especially if you had a recent endoscopy.

So, what are these superbugs? 

Carbapenem-resistant Enterobacteriaeceae (CRE) are so-called superbugs; bacteria that have become resistant to common antibiotics known as carbapenems. Carbapenem antibiotics include, doripenem, meropenem, ertapenem, and cilastatin/imipenem. These antibiotics are commonly prescribed to treat severe infections, such as bloodstream infection, urinary tract infections, pneumonia, and wound infections that are resistant to other antibiotics.

Klebsiella and Escherichia coli (or E-coli) are enterobacteriaceae that are normally found in the human gut. Occasionally they escape from the gut causing serious infections. Frequently these bacteria produce an enzyme that makes them resistant to carbapenem antibiotics; the enzyme protects the bacteria, preventing them from being killed by the carbapenem antibiotic. What makes matters worse is that sometimes CRE are resistant to all antibiotics, making them extremely dangerous to anyone who becomes infected by them.

Who's at risk for CRE infection?

Typically healthy people don't get CRE infections; they commonly affect patients in hospitals or long-term care facilities. These people are affected because they have weakened immune systems, and invasive tubes and catheters that make it easy for the bacteria to enter the body and cause infection. CRE are usually spread from person to person through contact with wounds or stool of an infected person. Treatment with certain antibiotics may also increase a person's risk for CRE infection.

Recently, however, special endoscopes used during a medical procedure, known as endoscopic retrograde cholangiopancreatography or ERCP, have spread the infection. During this procedure, an endoscope (known as a duodenoscope) is inserted into the patient's mouth and advanced into the intestine where the bile duct attaches. ERCP is used to diagnose and treat gallstones, open bile ducts, and obtain samples to diagnose tumors of the pancreas, bile ducts, or  gallbladder. For patients who require ERCP, it can be a life-saving procedure.

The scoop behind the scope

Researchers estimate that more than 500,000 ERCPs are performed annually in the United States; fewer than 100 cases of ERCP-associated CRE infection have been reported. Investigators believe that the intricate design of this special endoscope may be at fault, because it presents a special challenge for cleaning and disinfecting the device.  The Centers for Disease Control and Prevention, the Food and Drug Administration, and manufacturers recommend that healthcare workers strictly adhere to infection prevention practices and the manufacturer's guidelines for cleaning and disinfecting the device.

ERCP endoscope tip

The good news

Although an infection with CRE is very frightening; the chance of getting a CRE infection from endoscopy is rare. Moreover, there have been no reported cases of CRE infection related to routine endoscopy, such as colonoscopy.