乌鸦传媒

SAN DIEGO -- The rise in community-acquired Clostridium difficile appeared to be at least partly fueled by a surprising source -- dentists, according to researchers here.

Analysis of 7 years of surveillance data in five Minnesota counties found that 57% of C. difficile patients had been prescribed antibiotics, something that was assumed to be the cause of the disease, according to Stacy Holzbauer, DVM, a CDC field officer assigned to the Minnesota Department of Health in St. Paul.

But 15% of those patients were given the drugs by their dentists. In many cases that fact didn't find its way into the patient's primary care records, Holzbauer told reporters at the annual IDWeek meeting, sponsored jointly by the (IDSA), the (PIDS), the (SHEA), and the (HIVMA).

Dentists are allowed to write prescriptions for antibiotics, and often do when they are performing oral surgery or simply for prophylaxis in some patients, Holzbauer said. Indeed, one estimate suggests they write 10% of all such prescriptions, although the say that relatively few patients need such treatment.

Holzbauer said that at least part of the problem is that dentists, unlike primary care physicians, don't necessarily see the adverse effects of antibiotics, even though they might be aware of the risk in principle.

"No one goes to the dentist when they have diarrhea so [dentists] don't get the feedback," she said.

It's also not clear that dentists are routinely included in discussions about the risks of antibiotics, she said, adding they might be in a "blind spot in the antibiotic stewardship conversation."

While it is often thought of as a healthcare-associated issue, C difficile is on the rise in the community, commented Hilary Babcock, MD, of the Washington University School of Medicine in St. Louis, Missouri, who co-moderated the IDWeek media briefing.

"Understanding where and how and from whom people in the community are getting antibiotics that might predispose them to C difficile is an important part of understanding how to prevent C. diff." she said, adding that findings from Holzbauer's group were exciting and surprising.

The results come from analysis of active population- and laboratory-based surveillance data from 2009 through 2015 in five counties in Minnesota as part of the CDC's Emerging Infections Program, Holzbauer said.

The researchers defined a case as a positive C difficile toxin or molecular assay on a stool specimen from a person older than age 1 year who had not had a positive test in the previous 8 weeks. Cases were classified as community-acquired if the tested stool was collected no more than 3 days after hospital admission or as an outpatient, with no overnight stay in a healthcare facility in the previous 12 weeks.

The investigators interviewed all 1,626 patients determined to have community-acquired C difficile over the study period in order to try to pin down the cause of their illness.

All told, 926 patients reported being prescribed antibiotics, including 136 given them for dental procedures.

Patients who got antibiotics for dental work had a median age of 57, compared with age 45 for the others, were more likely to be given clindamycin (50% versus 10%), and were less likely to be prescribed fluoroquinolones or cephalosporins (6% versus 19%, and 7% versus 30%, respectively).

For 31 of the patients who said they received antibiotics for a dental procedure, primary medical records reported the fact, Holzbauer's group found. But in the interviews, 46 patients reported antibiotics for any reason that weren't documented in their medical records.

Holzbauer said it's not fair to lay the blame entirely on dentists, although it's likely that they need to be more aware that "antibiotics are not harmless." But patients need to report any antibiotic use to their primary care doctors and doctors need to make sure to ask. "It comes down to taking a good history," she said.

Comment