Antibiotics and hospital admission are both risk factors. The teamâ€™s interest was in correlating two known factors across different patients: does antibiotic use in one patient increase the chance that their hospital bedâ€™s next occupant will wind up with a C. difficile infection?
Led by Daniel Freedberg, MD, of the Columbia University Medical Center in New York, a recent study sought to explore a specific but potentially important aspect of Clostridium difficile (C. difficile) transmission. The gastrointestinal infection, which kills north of 27,000 people in the US annually, is commonly passed in hospitals. Antibiotics can be a risk factor, because they often kill off other bacteria that could fight the rise of C. difficile.
The team’s interest was in correlating these two known factors across different patients: does antibiotic use in one patient increase the chance that their hospital bed’s next occupant will wind up with a C. difficile infection?
The team looked at data from four different New York area hospitals, creating over 100,000 sets of “patient pairs” to compare. They ruled out any of the pairs where the subsequent patient had a history of C. difficile infection, or ones whose C. difficile developed within 48 hours of residence in the bed, deeming that to be too soon to consider correlated with the previous occupant. Of the remaining pairs, the subsequent occupant developed C. difficile between 2 and 14 days after admission in 576 cases.
Overall, the risk of a patient developing the infection was 0.72% if the previous tenant had been treated with antibiotics, compared with 0.43% among those who followed patients who were not. When 1,497 cases in which the first patient in the set had C. difficile were eliminated from the study, the difference remained.
The study itself acknowledges its limitations and the small correlation, but stresses the importance of the difference remaining steady even if the first patient did not have a C. difficile infection. It concludes by saying that “these data support the hypothesis that antibiotics given to one patient may alter the local microenvironment to influence a different patient’s risk for CDI.”
The study was published this week in JAMA Internal Medicine.