Hospitals have been trying for decades to stop the transmission of Clostridium difficile, a nasty, tough-to-kill microbe that causes painful diarrhea and is blamed for thousands of patient deaths each year.
One common tactic is enhanced disinfection of any hospital room occupied by a patient with the symptoms of the illness, called C. diff for short, ideally eliminating any bacterial spores that could infect subsequent patients.
But a new Columbia University study adds to a growing body of evidence that the bug can be passed along even by patients who do not have symptoms.
The researchers analyzed more than 100,000 pairs of patients who occupied the same hospital bed, one after the other, at four New York-area hospitals.
If the first occupant of a given bed was given antibiotics for some reason, the subsequent patient had a higher risk of developing C. diff, the authors reported in JAMA Internal Medicine.
That held true even when the initial patient had no C. diff symptoms, said lead author Daniel E. Freedberg, an assistant professor of medicine at Columbia.
That suggests the bacteria are being passed along by patients who were colonized with C. diff but not symptomatic, he said.
In patients colonized with C. diff, the administration of certain antibiotics can wipe out other bacteria, potentially allowing C. diff to flourish.
Among the 100,000 pairs of patients, 0.72 percent of the second patients in each pair developed a C. diff infection when the prior occupant of the bed had received antibiotics, compared with a 0.43 percent rate of infection when the prior occupant had not received antibiotics.