Infection of a dangerous superbug dubbed as the "phantom menace" is increasing in the U.S., making it an urgent threat to public health, according to a report released Tuesday by the U.S. Centers for Disease Control and Prevention (CDC).
The bacteria belong to carbapenem-resistant Enterobacteriaceae (CRE), a group that displays resistance to most antibiotics. Their plasmids encode an enzyme called carbapenemase that renders them resistant to carbapenem antibiotics.
Plasmids are mobile DNA material that is transferred easily from one bacterium to another. Therefore, the ability to resist antibiotics can also be passed on quickly to different kinds of bacteria. Thus, superbugs are "of greatest public health concern because of their potential for rapid global dissemination," according to the CDC.
The "phantom menace" superbug is not easily detectable. It is less resistant to antibiotics compared to other CRE, which is why it was not frequently studied, allowing it to stay under the radar.
"This is a tricky drug-resistant bacteria, and it isn't easily found. What we're seeing is an assault by the microbes on the last bastion of antibiotics," CDC director Thomas Frieden told The Washington Post.
The number of recorded "phantom menace" infections totals 43 in the U.S. and spread across 19 states from 2010 to 2015. The infected patients had an average age of 70. Some of them are believed to have caught the infection while traveling abroad, although local transmission could have occurred as well.
Frieden said the data on "phantom menace" infections could very well be "just the tip of the iceberg."
The CDC said that the rise in detection of CRE that allows Klebsiella pneumoniae - the pneumonia-causing bacteria - to be resistant to antibiotics, as well as the recent report about superbugs found in China that are resistant to the last-line antibiotic colistin, emphasizes "the continued urgency to delay the spread of CRE."
Incidentally, the superbug isolated in China was detected in a patient in Denmark, the Technological University of Denmark announced Thursday. National agencies have reportedly created an overview of the situation.
Lance Price, head of the Antibiotic Resistance Action Center at George Washington University, said the Danish researchers' discovery is "alarming."
"History shows that these mobile resistance genes can spread around the world quickly, silently riding in people, animals, and food," Price told National Geographic. "The news that MCR-1 has been discovered in Denmark suggests that this scenario is playing out in real time."
