Outpatient Prescribing May Reduce Risks from Antibiotics for Clostridium Difficile

Antibiotics remain a top risk factor for community associated Clostridium difficile (C. difficile) infection in adults, which highlights the importance of reasonable outpatient prescribing, according to a recent report.

Researchers from the Centers for Disease Control and Prevention (CDC) studied patients at hospitals across the US between Oct. 2014 and March 2015. There are 10 states that participate in C. difficile infection surveillance, where the researchers gathered their data: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon and Tennessee.

From these sites, the study authors identified 452 patients, or 226 matched pairs, to enroll in the study. Each was over the age of 18 and had a stool specimen that tested positive for C. difficile. Their objective was 2-fold: the researchers wanted to determine if exposures to certain outpatient settings and antibiotic classes were independently linked to infection, and also wanted to explore the risk factors, such as exposure to medications, household items and food products.

Half of the patients were older than 60 years, while 70% were female patients. The most reported symptoms among the patients were diarrhea, abdominal pain, nausea and fever. Comorbidities among the patients included hypertension, obesity and depression, though there were also patients with inflammatory bowel disease, chronic kidney disease and cardiac disease.

A majority of the patients, 82%, reported at least 1 outpatient medical care in the 12 weeks preceding their infection, compared with 57% of controls, the study authors wrote. In the 2 weeks preceding infection, the case patients were more likely than control subjects to have experienced outpatient health care exposure, the researchers learned.

The most common of these exposures were visits to doctors’ and dentists’ offices, though emergency department visits, outpatient procedure center visits, outpatient surgery center visits, and urgent care clinic visits were all noted exposures among case patients within 2 weeks of their infection.

Concerning antibiotics, the investigators found that 62.2% of case subjects were exposed to antibiotics in the 12 weeks leading to their infections than compared to just 10% of controls. Additionally, more than half of the case patients received antibiotics within 2 weeks of their infection onset. The most common reason for their antibiotic use was an ear, sinus, or upper respiratory infection, skin infection, dental procedure, or a urinary tract infection.

The investigators also explored lifestyle factors. Case patients were not any more likely than controls to work or volunteer in a health care facility or have a household member of any age in diapers, or attend daycare facilities.

In terms of dietary intake, there was no difference between the case subjects and controls that had a diverse diet or a high frequency of consumption of various food types.

“Increasing evidence has shown that C. difficile environmental contamination in hospitals can contribute to transmission of hospital-onset C. difficile infection,” said study author Alice Guh, MD, MPH, medical officer, Divison of Healthcare Quality Promotion, CDC. “However, less is known about the role of environmental contamination in outpatient settings. We found that exposure to emergency departments could increase the risk of community-associated C. difficile infection, independent of antibiotic use, suggesting that emergency departments and similar types of outpatient settings could be an environmental reservoir for community-associated C. difficile.”

Dr. Guh added that despite all this, more tests are needed to outline the role of emergency departments and similar outpatient settings in the transmission of C. difficile infection.

“Physicians need to recognize the potential harm to patients from inappropriate antibiotic prescribing and to be judicious in their use of antibiotics,” noted Dr. Guh.

The paper, titled “Risk Factors for Community-Associated Clostridium difficile Infection in Adults: A Case-Control Study,” was published in the IDSA’s Open Forum Infectious Diseases journal.