Late last year, a story out of Toronto’s renowned Hospital for Sick Children (Sick Kids) led the national news — and set off alarm bells in the minds of millions of Canadian parents. A child there was treated after acquiring bacterial meningitis, a potentially fatal infection. More disturbing was the news that a number of antibiotics designed to fight the infection in children had proven completely ineffective, forcing doctors to resort to a powerful drug normally reserved for adults. It was but one example of a “superbug,” a type of bacteria that resist commonly prescribed antibiotics, and a cause of growing concern in Canada. “This case was sort of like when you send the canary down into the coal mine. The fact that we’re starting to see more and more of these superbugs is a bit of a wake-up call for all of us,” says Dr. Jeremy Friedman, head of pediatric medicine at Sick Kids.
It’s not a new problem, notes Dr. Joanne Embree, head of medical microbiology at the University of Manitoba. “Back in the 1940s, when penicillin was first used, the Staphylococcus aureus bug was all-sensitive to it, but it took only a matter of months before resistant strains showed up,” says Dr. Embree. “The bacteria didn’t wait around — they responded in a hurry.” Most bacteria have not followed this pattern, but for some, the invention of new and stronger antibiotic treatments over the years was followed by novel mutations, as the bug fought back and sought to stay alive — resulting, eventually, in the superbugs we see today. Misuse of antibiotics has been a key factor — over-prescription, yes, but also improper use. If an antibiotic has been prescribed for 7-10 days, but you stop giving it to your child when she feels better after three, “you’ve killed a large percentage of the bugs, but the ones that survive will develop a resistance to the antibiotic the next time they see it, and that contributes to the development of a superbug,” says Dr. Friedman. All of this can be likened to a dance. “For certain bugs, it will be an escalating thing; we will have to keep outwitting the bugs with a new antibiotic that they haven’t seen before,” says Dr. Friedman. “It’s a bit of an ongoing tango.”
There are a number of different antibiotic-resistant bacteria that can be considered superbugs, including Streptococcus pneumoniae 19A (which infected the child treated at Sick Kids), vancomycin-resistant enterococci (VRE), Clostridium difficile (C. difficile) and Methicillin-resistant Staphylococcus aureus (MRSA). The latter in particular has become a serious problem in the United States, leading to school closures in a number of states and resulting in an estimated 18,650 deaths in 2005 alone — which is more than the number of AIDS deaths in the same year. It has historically been a hospital germ, but now a community strain is proving very troublesome. In most cases, MRSA causes soft tissue infections — giant boils, abscesses — but it can develop into bloodstream infections, severe hemorrhagic pneumonia, and other serious ailments causing death.
Often those who experience the most dramatic effects are those with weaker immune systems, and kids are one of several groups at risk for the most severe form of the disease, says Dr. John Conly, an infectious diseases specialist and director of the Centre for Antimicrobial Resistance at the University of Calgary and Calgary Health Region. And the bug is now marching north. “I just had a call from a pediatric colleague yesterday who said that they have someone with toxic shock syndrome from community MRSA. We’re beginning to see this in Canada now.” But there’s no reason to panic, assures Dr. Friedman. “I’m not saying that people should be relaxed about it, but on the other hand I don’t think that we should necessarily worry that the sky is falling,” he says, noting that, in addition to the various treatment options available, superbugs are still quite unusual and the odds are against picking one up.
A superbug doesn’t necessarily differ from a regular one in terms of symptoms — it’s all about how it responds to treatment. “When her child is placed on an antibiotic, a parent should get instructions from her doctor about what to expect. For instance, when she can expect the swelling and fever to go down, and when to come back if she has concerns,” advises Dr. Embree. If symptoms aren’t improving — or are worsening — a superbug may be at work. Physicians can treat them, but they have to recognize what’s going on, and reach beyond the drugs typically used. For instance, community MRSA is still sensitive to some less common antibiotics. “The first line won’t work, but there are second-line agents that are readily available and can be used to treat these infections. And that’s good news,” says Dr. Conly.
And the battle is not lost. Dr. Embree notes that doctors have adjusted their practices to ensure enough potency to fight bacteria. “We tend to use more combination antibiotics when we’re worried about this, so they can work together,” says Dr. Embree. “It gives a right-left punch.” At the same time, the medical community is working hard to turn the tide, prescribing fewer antibiotics and seeking to ensure that they’re used in an optimal way, as well as creating new vaccines. “We’re not giving up without a fight,” she says.
A minor germaphobe, contributing editor Tim Johnson has become even more diligent in his hand-washing and bathroom-doorknob-avoidance techniques since writing this story.
Superbug bacteria are spread exactly like a virus, through direct and indirect contact and droplet transmission through sneezing and coughing.