A Tough Bug
Believed to be aided largely by the use of broad-spectrum antibiotics that knock out the colon’s natural flora, C. diff in the hospital—as well as nursing homes and acute-care facilities—has raged for much of the past decade. Its rise is tied to the emergence of a new hypervirulent strain known as BI/NAP1/027, or NAP1 for short. The strain is highly resistant to fluoroquinolones, such as ciprofloxacin and levofloxacin, which are used often in healthcare settings.
“A fluoroquinolone will wipe out a lot of your normal flora in your gut,” Dr. Gould says. “But it won’t wipe out C. diff, in particular this hypervirulent strain. And so this strain can flourish in the presence of fluoroquinolones.” The strain produces up to 15 to 20 times more toxins than other C. diff strains, according to some data, she adds.
Vancomycin (Vanconin) and metronidazole (Flagyl) are the most common antibiotics used to treat patients infected with C. diff. Mortality rates are higher among the elderly, largely because of their weaker immune system, Dr. Gould says. Studies have generally shown mortality rates of 10% or a bit lower.1
More recent studies have shown that the number of hospital-related C. diff cases might have begun to level off in 2008 and 2009. Dr. Gould says she thinks the leveling off is for real, but there is debate over what the immediate future holds.
“There’s a lot of work and initiatives, especially state-based initiatives, that are being done in hospitals. And there’s reason to believe they’re effective,” she says, adding it’s harder to get a good picture of the problem in long-term care facilities and in the community.
Dr. Cohen with the IDSA says it’s too soon to say whether the problem is hitting a plateau. “CDC data are always a couple of years behind,” he says. “Until you see another data point, you can’t tell whether that’s just a transient flattening and whether it’s going to keep going up or not.”
Kevin Kavanagh, MD, founder of the patient advocacy group Health Watch USA and a retired otolaryngologist in Kentucky who has taken a keen interest in the C. diff problem, says he doesn’t think the end of the tunnel is within view yet.
“I think C. diff is going to get worse before it gets better,” Dr. Kavanagh says. “And that’s not necessarily because the healthcare profession isn’t doing due diligence. This is a tough organism.—it can be tough to treat and can be very tough to kill.”
The Best Defense?
Because C. diff lives within protective spores, sound hand hygiene practices and room-cleaning practices are essential for keeping infections to a minimum. Alcohol-based hand sanitizers, effective against other organisms including MRSA, do not kill C. diff. The bacteria must be mechanically removed through hand washing.
And even hand washing might not be totally effective at getting rid of the spores, which means it’s important for healthcare workers to gown and glove in high-risk rooms.
Sodium hypochlorite solutions, or bleach mixtures, have to be used to clean rooms occupied by patients with C. diff, and the prevailing thought is to clean the rooms of patients suspected of having C. diff, even if those cases might not be confirmed.
Equally important to cleaning and hand washing is systemwide emphasis on antibiotic stewardship. A 2011 study at the State University of New York Buffalo found that the risk of a C. diff infection rose with the number of antibiotics taken.2
If someone is very sick and you’re not sure what is going on, it’s very reasonable to treat them empirically with broad-spectrum antibiotics. The important thing is that you send the appropriate cultures before so that you know what you’re treating and you can optimize those antibiotics with daily assessments.
—Carolyn Gould, MD, medical epidemiologist, division of healthcare quality promotion, Centers of Disease Control and Prevention, Atlanta