Putting the CRE Superbug Under the Microscope

In modern times, bacterial infections are usually more of an irritant than serious threats to human health. Thanks largely to the introduction of antibiotics, millions have people have been able to beat back the onslaught of harmful microbes. Some bacteria, however, have the ability to repel antibiotic medications, making them a serious danger to those they infect. One such “superbug” that has recently made headlines is carbapenem-resistant Enterobacteriaceae (CRE).

A Hard Target

CRE is a bacterial family that has developed a strong resistance to many types of antibiotics. The reason for this durability stems largely from an enzyme called Klebsiella, which neutralizes antibiotics before they can eliminate CRE bacteria. Because of their stout defenses against such medicines, CRE microbes are notoriously difficult to kill, rendering them extremely dangerous should they find their way into the bloodstream. CRE infections have an alarmingly high mortality rate, ranging from 40 to 50 percent.

Fortunately, this often-deadly bacteria cannot infect others through the air. Instead, CRE spreads via direct physical contact with those who are infected or colonized with CRE germs. Those unlucky enough to be infected with CRE frequently develop symptoms after touching an infected wound or stool. Consequentially, CRE bacteria usually afflicts hospital workers and patients.

Preventing the spread of CRE inside hospital environments is not an easy task. CRE microbes can entrench themselves in hard-to-reach areas, and may also wind up on surgical devices and other sorts of medical equipment. In addition, hospital staff can also spread such superbugs by failing to practice proper hygiene while on the job.

Recent Outbreaks

Many people first heard of CRE in early 2015, when a deadly outbreak of this bacteria occurred at Ronald Reagan UCLA Medical Center. A total of seven patients at this hospital were infected, resulting in two deaths. Moreover, these initial cases could be just the tip of the iceberg, as hospital officials warned that up to 179 people could have been stricken with CRE.

It is believed that CRE infected these seven individuals during endoscopic procedures performed from October 2014 to January 2015.  Two specialized endoscopes were identified as the possible vehicles by which CRE bacteria entered the patients’ bodies. These devices, commonly known as duodenoscopes, were removed from use after they were linked to the outbreak.

Duodenoscopes are used on a regular basis in the United States. Each year, about 500,000 people undergo procedures involving this instrument. In the wake of the UCLA outbreak, the US Food and Drug Administration (FDA) issued a safety communication regarding duodenoscope cleaning procedures.

The FDA statement warned that harmful microbes could still lurk on such devices even after they are cleaned according to guidelines. A number of medical researchers fault the design of the duodenoscope for this problem. In addition, the FDA also reported that it had received 75 reports of duodenoscope contamination from the start of 2013 through the end of 2014. These reports involved 135 patients, who may have been infected with harmful bacteria lingering on reused duodenoscopes.

Unfortunately, the outbreak at the UCLA Medical Center wasn’t the first time CRE reared its ugly head, and it certainly won’t be the last. Around the same time that it appeared on the west coast of the United States, CRE bacteria claimed two more lives in North Carolina. Both of these individuals were treated at the Carolinas Healthcare System (CHS). By late February 2015, fifteen people with existing CRE infections had sought treatment at CHS facilities. Furthermore, three additional people have contracted CRE at this system of hospitals.

Research published in October 2014 highlighted the threat posed by CRE. This study found that 150 Americans had been sickened in a half-dozen outbreaks of CRE and other bacteria since 2012. Occurring in such states as Pennsylvania, Illinois and Washington State, each of these outbreaks was connected to contaminated duodenoscopes.

Updated Labels?

With CRE bacteria garnering so much media attention, it appears that changes to the duodenoscope cleaning process could be forthcoming. A story by the Reuters News Agency revealed that the FDA was in the process of updating the content of these devices’ labels. The FDA’s Center for Devices and Radiological Health chief scientist , Dr. William Maisel, told Reuters that the agency was “working to expedite modifications to the label. We are also talking about updating the risk information.”