(HealthDay News) – About half of Clostridium difficile cases are genetically distinct from previous cases, suggesting that symptomatic patients are not the only source of transmission, according to a study published in the Sept. 26 issue of the New England Journal of Medicine.
David W. Eyre, BM, BCh, from the University of Oxford in the United Kingdom, and colleagues performed whole-genome sequencing of 1,223 isolates of C. difficile taken over a 3.6-year period from 145 inpatients and outpatients to compare single nucleotide variants (SNVs).
The researchers found that only 35% of isolates were genetically linked, with no more than two SNVs from at least one earlier case. Of these, 38% had close hospital contact with another patient and 36% had no hospital or community contact with another patient. In contrast, 45% of isolates were genetically distinct, with more than 10 SNVs from all previous cases.
“Over a three-year period, 45% of C. difficile cases in Oxfordshire were genetically distinct from all previous cases,” Eyre and colleagues conclude. “Genetically diverse sources, in addition to symptomatic patients, play a major part in C. difficile transmission.”
Several authors disclosed financial ties to the pharmaceutical industry.