Superbugs: Why they’re dangerous, where they are and how they spread

The threat: A family of germs called Carbapenem-resistant Enterobacteriaceae, or CRE, that are resistant to Carbapenems, a class of antibiotics often referred to as drugs of last resort. Antibiotic resistance is a global worry, with the worry that routine procedures could become life-threatening if there are no antibiotics to treat them

Why it's a worry: CRE is highly resistant, potentially deadly – up to 50 per cent of people who acquire a CRE infection in their bloodstream die as a result – and can transfer their resistant traits to other bacteria.

How it spreads: The fecal-oral route, which means the best prevention is hand-washing.

Where it is: CRE is widespread in several countries, including India, China, Greece and parts of the United States. It has taken hold primarily as a result of overuse and misuse of antibiotics.

How big a problem is it: There are still relatively few cases of CRE in Canada compared to other so-called superbugs such as MRSA (Methicillin-resistant Staphylococcus aureus) and C. difficile. A Public Health Agency of Canada report on Antimicrobial Resistant Organisms for the years 2007-2011 found 160 cases of carbapenemase resistance compared with more than 14,000 cases of C. difficile over the same period. But those numbers are likely to increase, in part as a result of increased surveillance – the more hospitals look for CRE, the more they are likely to find – and as the bug makes its way around the world.

The terminology: The study of carbapenem resistance involves multiple acronyms, including CPEs, or carbapenemase-producing Enterobacteriacaea, for bugs that have acquired the ability to produce an enzyme that breaks down the antibiotic, rendering it useless. There are different types of CPEs, including KPC (Klebsiella pneumoniae carbapenemase) – which has become widespread in the United States since it was first reported in 2001 – and NDM (New Delhi Metallo-beta-lactamase), which was first reported in the U.S. in 2009. In Canada, where CRE has been monitored for the past few years, KPC is more common in central and eastern Canada while NDM is more common in B.C., according to the B.C. Centre for Disease Control.

What is a superbug and why is it resistant to antibiotics? Click here for explainer