Clostridium difficile, a dangerous infection that typically plagues hospital patients, is increasingly being found outside hospitals, and traditional C. diff risk factors may no longer explain many infections, a physician told NPR.
Five insights from the report, written by Clayton Dalton, MD, a resident physician at Boston-based Massachusetts General Hospital:
1. In addition to antibiotic use being a risk factor for C. diff, researchers found hospitalization was a dominant risk factor for the disease, so much so that C. diff became known almost exclusively as a hospital-acquired infection, Dr. Dalton said.
2. Although improved infection control in hospitals started to curb infection rates, several studies suggested the issue may span far beyond hospital settings. In 2006, a North Carolina hospital found 35 percent of C. diff infections were occurring outside the hospital, and only half could have involved antibiotic exposures.
3. In 2011, the CDC estimated about 350,000 C. diff infections occurred outside hospitals, 46 percent were fully community-acquired and 36 percent had no antibiotic exposure. Last year, researchers in California found 1 in 10 emergency room patients with diarrhea tested positive for C. diff, and that 40 percent of these patients had no risk factors.
4. "Traditional risk factors — antibiotics and hospitalization — can no longer explain many infections," Dr. Dalton wrote. "Scientists have long suspected that antibiotics trigger C. diff infections by disrupting the intestinal microbiome. Could it be that other factors are having a similar effect? Is our microbiome growing more susceptible to these dangerous infections?"
Alice Guh, MD, a CDC researcher, thinks so. "There's definitely something going on, "but we don't fully understand what," she said.
5. Diet significantly affects the microbiome and could play a role, Dr. Guh said. A recent study found trehalose, a common food additive, markedly enhances the virulence of C. diff, but Dr. Guh said it has been challenging to replicate these findings.
Common medications could also be involved, Dr. Guh said. Popular drugs for heartburn are linked to C. diff infections, and have been shown to disrupt the microbiome.
"Could [rising C. diff rates] be a sign of an even larger problem — that our guts are becoming ever more fragile?" Dr. Dalton wrote. "Perhaps C. diff is just a canary in the mine."