“An additional driver of this rise in incidence could be the recent emergence of new strains of C. difficile, such as NAP1, which has been shown to be a risk factor for recurrent CDI (c diff),” says study senior author James D. Lewis, MD, MSCE professor of Gastroenterology and senior scholar in the Center for Clinical Epidemiology and Biostatistics.

Kids and Pets

A study in Infection Control & Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America, found that patients with C diff bacteria can colonize or infect household contacts. “These infections, causing diarrhea and inflammation of the colon, can be serious, so it is important that everyone follows simple hygienic practices, like hand washing with soap and water, even in your own home,” says Vivian Loo, MD, MSc, lead author and an infectious disease specialist and medical microbiologist at the McGill University Health Centre (MUHC), investigator at the Research Institute of the MUHC, and professor at McGill University.

The study showed 13.4 percent of the 67 human household contacts had C diff in their stool or rectal samples. One adult household member had diarrhea and the remaining eight were asymptomatically colonized. Of those colonized, over half were under the age of 5, including five in diapers.

Pets, too, came in as strong asymptomatic carriers at 26.7 percent. Researchers found the strains carried by the pets and by their human contacts were indistinguishable or closely related, indicating pets can be reservoirs for re-infection or transmission of C diff. “Our research suggests that household transmission from patients with C. difficile infection could be responsible for a bacterial reservoir for community-associated cases,” said Loo.

C Diff and Gastric-Suppression Meds

Researchers at the Mayo Clinic found patients who use gastric-suppression medications are at a higher risk for recurrent C diff infections. C diff  bacteria can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon. The Mayo Clinic study was published in JAMA Internal Medicine.

“In our study, we found that use of gastric-acid-suppression medications are associated with a statistically significant increased risk of development of recurrent C diff in patients with a prior episode of C diff,” says Sahil Khanna, MBBS, a gastroenterologist at the Mayo Clinic and senior author of the study.

Dr. Khanna says gastric-suppression medications studied include proton-pump inhibitors, such as omeprazole (such as Prilosec OTC); and histamine 2 blockers, such as ranitidine (such as Zantac). Both are commonly used for gastric-reflux disease, peptic-ulcer disease, and dyspepsia. Dr. Khanna urges caution in interpreting these findings due to variables not considered in the study, such as the underlying reason why the gastric-acid suppressant was needed.

Hospitals and C Diff

The epicenter for C diff may very well be hospitals. Outpatient antibiotic use is a primary risk factor for acquiring C diff, according to a study published in Open Forum Infectious Diseases. According to the study, just a trip to the ER (emergency room) may be a risk factor, independent of antiobiotic use or being admitted to the hospital.

While most C diff infections are associated with hospital antibiotic use, as of 2014, they accounted for 41 percent of all C diff infections, says the CDC. In this case-control study, researchers enrolled adult patients from 10 U.S. sites during 2014 to 2015 who tested positive for C diff as an outpatient, or within three days of being hospitalized, and who had not been admitted to a health-care facility within the past 12 weeks.

“There’s a lot of work that needs to be done in terms of improving outpatient prescribing practices and making sure that providers are appropriately prescribing antibiotics,” study author Alice Y. Guh, MD, MPH, of CDC. “Health-care associated C. difficile infection is still a huge burden, but there is increasingly more recognition that community-associated C. difficile can occur. Outpatient antibiotic use is a risk factor, and we need to improve antibiotic stewardship not just in inpatient settings but also outpatient settings.”