CRE Superbug Infection May Spread Quickly And Without Showing Symptoms

John Houck

Known as carbapenem-resistant enterobacteriaceae (CRE), this group of superbugs is spreading faster and more widely than previously predicted. While the bacteria infects just over 9,000 and kills about 600 people annually in the U.S., a new study revealed that they may be infecting many more without showing any symptoms.

These particular superbugs are especially dangerous to humans. CREs have a unique ability to resist any currently available antibiotics, making treatment very difficult for health practitioners. Even one of the strongest medicines, named carbapenem, doesn't seem to deter these "nightmare" superbugs. This powerful antibiotic is typically only used as a last resort for the toughest cases.

For the study, researchers analyzed more than 250 samples of CRE collected from infected patients at four U.S. hospitals over a 16-month period. The samples were taken from patients' blood, urine, and respiratory tract. The Harvard-MIT research team wanted to find out how frequently superbug infections occurred and better define which bacterial strains were causing the infections.

"We tried to get an idea of what the population was, and that enabled us to capture the diversity of these things, which were causing disease in the hospitals we studied," said William Hanage, an associate professor of epidemiology at the Harvard Chan School, as cited by CNN.

The team discovered eight species of CRE, each with different genetic backgrounds and resistance genes. With such diversity, the researchers concluded the antibiotic-resistant superbugs are spreading faster and more easily than previously thought.

Alarmingly, the study also found that some species did not have the necessary genes to resist carbapenems, but were able to survive, nonetheless. The bacteria were able to find a way to resist being eliminated when exposed to the powerful antibiotic and researchers have no idea how.

Hanage and his colleagues failed to find any clear method of transmission for the superbugs. They are infecting healthy people without causing any notable signs of illness, meaning the bacteria are silently moving from person to person.

"While the typical focus has been on treating sick patients with CRE-related infections, our new findings suggest that CRE is spreading beyond the obvious cases of disease," Hanage warned, according to a Tech Times report. "We need to look harder for this unobserved transmission within our communities and healthcare facilities if we want to stamp it out."

The study did not determine how patients originally contracted the superbugs outside the hospitals where the samples were obtained. However, a recent case of a CRE infection has scientists desperately wanting to know how these superbugs find their way into the population.

As previously reported by the Inquisitr, a woman in Reno, Nevada, died from a superbug infection in September. She had been living in India for an extended period and returned to the U.S. in early August.

Shortly after arriving, she was hospitalized with various symptoms related to systemic inflammatory response syndrome. Doctors had eventually determined she had contracted a particular CRE called Klebsiella pneumoniae carbapenemase (KPC), a variety of superbug that causes pneumonia and urinary tract infections.

"There are two primary types of CRE. One of them is called New Delhi metallo-beta-lactamase, or NDM, and another one is called Klebsiella pneumoniae carbapenemase, or KPC," said Lei Chen, senior epidemiologist for the Washoe County Health District, per CNN.

Every available antibiotic was given to the Reno woman, but none were effective. The woman, in her 70s, developed septic shock from the infection and died. Fortunately, she was in a single-patient room and the infection was unable to spread to others.

While superbug infections still remain rare, health experts fear a global pandemic could result if left unchecked. A report published in 2016 estimated that 10 million people per year would die from antibiotic-resistant infections by the year 2050 if nothing were done to combat the threat.

[Featured Image by George Frey/Getty Images]