But C. diff is neither so easily controlled nor so selective about whom it strikes anymore. A new, savage and even deadly strain now appears to be at large, one that may have sickened as many as half a million people in the U.S. in 2005double the number from just five years ago. The infections are turning up in young, healthy people, many of whom have not been hospitalized at all. People already taking some kind of antibiotics appear to be especially susceptibleno surprise since the use of such germ killers can, paradoxically, help drug-resistant strains emerge. But disease trackers are alarmed to discover that common heartburn medications can also dramatically boost your risk of contracting C. diff. Whatever the co-factors in the pathogen's rise, health officials are fighting to control itfast.
"It's a new phenomenon. It's just emerging," epidemiologist L. Clifford McDonald of the Centers for Disease Control and Prevention told The Washington Post, one of the first publications to give the disease significant coverage. "We know it's happening, but we're really not sure why it's happening or where this is going."
What doctors do know about all strains of C. diff they don't like. The bug is found in the colon, is a known cause of colitis and can be spread by even trace amounts of feces. It's tougher to kill with antibacterial soap and household cleansers than many germs are, which means that while keeping clean helps, it's no guarantee. Worse, the new strain is resistant to the common type of antibiotics known as floroquinolones, easily shaking off one of the most powerful weapons doctors would normally use to control it.
The New England Journal of Medicine recently published a paper in which investigators surveyed 187 cases of C. diff at eight health care facilities in Georgia, Illinois, Maine, New Jersey, Oregon and Pennsylvania. More than half of the cases were caused by the new, more dangerous strain. The CDC conducted a survey of its own, profiling 33 recent cases in four states. Twenty-three of the people had never been hospitalized and the other 10 were women who had had only brief hospital stays to deliver babiessuggesting that the new strain is ranging freer than any C. diff has before. One 31-yr.-old woman in the study, who was 14 weeks pregnant with twins, died of the disease. An even more chilling paper in the New England Journal surveyed 1,703 patients with C. diff in 12 hospitals in Quebec; 422 of those victims died.
Overuse of antibiotics helped breed the new bug in two ways. First, the simple rules of natural selection dictate that when a drug kills most of the members of any species of pathogen, those individuals that do withstand the assault did so because they had a natural resistance to the chemical. It's the same phenomenon that breeds pesticide-resistant insects on farms. What's more, since many antibiotics wipe out numerous species of bacteria at once, the drugs inadvertently create a nice, clear field in which those that do survive can thrive.
Anti-heartburn drugs may only make things worse, with one study suggesting that people taking the type of medications marketed as Prilosec and Prevacid are almost three times as likely to suffer a C. diff attack as non-users, and those taking the type marketed as Pepcid or Zantac may be twice as likely. It seems that bacteria don't like stomach acid any better than consumers do, and when you suppress it chemically the bugs have a better chance of surviving.
So what to do? For one thing, the CDC and other groups caution that there's no cause for panic. If you truly need to go to the hospital, goeven with the increased risk of encountering C. diff there. What's more, truly essential antibiotics should still be prescribed and taken. It's the more casual dosingfor sore throats or mild infections that could clear up on their ownthat create the problem. Staying clean and washing up is critical. And for those who do contract the new strain of the disease, the prognosis is nowhere near hopeless. The CDC recommends discontinuing the use of other antibiotics if possible and treating the infection with those antibiotics known as vancomycin or matronidazole. Constant monitoring is important, since the disease may retreat for a time and then reemerge. Like all new bugs, the super C. diff may still hold some surprises. For the moment at least, science is managing to keep pace with it.