Superbugs have become a topic of discussion in the media. MRSA is one of the most common talked about superbugs that is now spreading from the hospital to the community.
A lot of media attention has been given to the topic of "superbugs" and the threat that they pose. Accounts often border on sensationalism, seemingly with the intent to provoke fear, rather than to educate the public. One of the most talked about "superbugs" is MRSA - methicillin-resistant Staphylococcus aureus. MRSA used to be associated with hospital-acquired (nosocomial) infection, but is now being encountered more and more commonly in community-acquired infection. Is MRSA a superbug? For that matter, what is a superbug?
When I hear the term superbug, my imagination creates an image of a germ in a super-hero cape. And, of course, this super-hero represents evil rather than good. If I wanted to carry this fantasy a little further, and if I relied on drugs as a cure all, as it seems our pharmaceutical companies would have us believe, I would envision MRSA as the arch-rival of Rx-Marvel or some other caped drug who fights to eradicate the evil MRSA.
Presumably, superbugs are those with special virulence factors that result in the ability to cause infection more readily, cause more severe infection, and/or be extremely difficult to treat.
Had we coined the term superbug in the 1960s, penicillin-resistant Staphylococcus aureus, commonly referred to as "staph", would have been considered a superbug. The emergence of methicillin resistance is similar to the emergence of penicillin resistance in staphylococcus. I'm not sure how many of you can remember back that far, but if you can you may also remember that staph infections occurred just as commonly in those days, and were usually treated with penicillin.
Eventually, Staphylococcus aureus developed resistance to penicillin, and today most strains of the organisms are untreatable using penicillin. Today, we are experiencing the same trend with MRSA, and although infections involving MRSA are still more commonly encountered in a hospital or healthcare environment - hospital acquired MRSA (HAMRSA) - the organism is increasingly being isolated from infections acquired in the community - community-acquired MRSA (CAMRSA). To date, CAMRSA infections have been associated with infection in marginalized populations including prison inmates, homeless people and injection drug users; however, infections are increasingly being reported in sports team participants, and are also being reported in the general population in a number of countries. This trend will no doubt occur in Canada as well.
Next week we'll discuss the differences between Staphylococcus aureus, hospital or healthcare-acquired methicillin-resistant Staphylococcus aureus (HAMRSA), and community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA).
