Dangerous strain of C. Difficile causing outbreaks of diarrhea

A new strain of the bacteria *Clostridium difficile* is emerging in epidemic proportions in health care facilities in the United States and Canada. Two studies reported early online in the *New England Journal of Medicine* studied cases at [twelve hospitals in Quebec](http://content.nejm.org/cgi/content/abstract/NEJMoa051639) and [seven hospitals and an extended care facility in the United States.](http://content.nejm.org/cgi/content/abstract/NEJMoa051590).

Both the numbers and severity of Clostridium difficile-associated disease (CDAD) appear to be increasing in the United States according to researchers at the Centers for Disease Control, and they attribute this to the the new strain which they have labeled BI/NAP1. While the strain had been seen in rare cases previously by the CDC, it was a major contributor to CDAD in the nearly 200 cases studied in US health care facilities.

BI/NAP1 is resistant to fluoroquinolones. Some of the brand names for the fluoroquinolones are Cipro, Avelox, Floxin, Levaquin, Maxaquin, Noroxin, and Tequin. The researchers believe that increasing use of these drugs in health care facilities has allowed the stronger, drug-resistant bacterial strain to emerge and flourish.

The CDC studied samples from nearly 200 patients in 8 health care facilities. More than half the cases of CDAD included the BI/NAP1 strain. Symptom-causing toxins were significantly higher in those cases with 18 times the level of toxin A and 23 times the level of toxin B. The rare binary toxin CDT was also found in samples positive for the BI/NAP1 strain.

The CDC research team found that the strain was identical to one identified in Canada and [described by Vivian G. Loo, M.D. in the NEJM](http://content.nejm.org/cgi/content/abstract/NEJMoa051639). Dr. Loo and her team studied over 1,700 hospitalized patients with c.difficile disease over a six month period in 2004. They found over 80% of them had infections resistant to fluoroquinolones and positive for the binary toxin.

Overall nearly 7% of patients in the Canadian study died as a result of c. difficile, a substantially larger percentage than had been seen previously. Both the rates of infection and death rates increased with age. In addition, some patients in both Canada and the US required removal of their colon (*colectomy*).

Compared to the control cases, patients with CDAD were almost four times as likely to have been treated with fluoroquinolones or cephalosporins prior to developing the severe diarrhea.

L. Clifford McDonald, M.D. and the Centers for Disease Control say that prevention is key to controlling the outbreak. They suggest that:

+ Health care facilities track the incidence of *c.difficile associated disease* including outcomes for patients diagnosed with CDAD.
+ Procedures be developed to identify and treat CDAD early.
+ Patients be isolated and contact precautions (gowns and gloves) be used by health care workers.
+ Handwashing with soap and water be strictly observed. Since c.difficile bacteria is resistant to alcohol, alcohol-based hand sanitizers should not be used.
+ Most important is restrained use of the antibiotic agents such as the fluoroquinolones that are associated with the disease.

Additional discussion of the studies can be found on [MedPage Today](http://www.medpagetoday.com/InfectiousDisease/PublicHealth/tb/2254)