What it means to you: While other drug-resistant infections, like Methicillin-resistant staphylococcus aureus (MRSA), have been garnering public attention, another deadly foe has been spreading silently and stealthily. According to a recent APIC study, the number of patients afflicted with Clostridium difficile (C. diff) may be much higher than initially thought.

The APIC study—the largest and most comprehensive of its kind—represents a one-day snapshot of C. diff rates at 648 healthcare facilities in 47 states—12.5 percent of all acute care hospitals in the U.S. Each facility supplied data for a single day between May and August 2008, and the results are truly alarming: 13 out of every 1,000 inpatients in the survey were either infected or colonized with C. diff.

These numbers represent rates 6.5 to 20 times greater than previous estimates of more limited scope, some of which are highlighted in this Emerging Infectious Diseases Journal report and this article in the Journal of Infectious Diseases.

Based on American Hospital Association data, the U.S. inpatient population is approximately 547,945 patients on any given day. More than 7,000 of those patients are infected with C. diff, according to APIC’s new study, adding a cost of $17.6 million to $51.5 million to the healthcare system.

The scoop: C. diff was under the radar until the more virulent North American Pulse-field type 1 (NAP1) strain of the bacteria was discovered in 2000 at the University of Pittsburgh Medical Center. That outbreak killed 18 patients, according to this report in The Wall Street Journal.

The drug-resistant strain is particularly dangerous in hospitals, where many patients receive antibiotics that eliminate the “good” bacteria that normally keep C. diff in check. Nearly two-thirds of the cases reported in the APIC study were healthcare-associated, and almost 80 percent of those patients had received antibiotics prior to infection. Controlling the spread of C. diff  has proven particularly difficult as well because of its extremely contagious nature and its resistance to traditional infection control measures—most hospital cleaners won’t kill the bacteria, and alcohol-based hand sanitizer doesn’t kill the spores.

To fight back, hospitals are being more conservative in prescribing universal antibiotics and more vigilant in isolating infected patients and cleaning those patients’ rooms floor to ceiling with powerful bleach solution.