Much has been written and spoken on the subject of how best to reduce the incidence of healthcare acquired infections (HCAIs) in healthcare facilities. But a new study, published in the New England Journal of Medicine, offers new information on the fight against HCAIs.
Over three years, Professor Tim Peto and researchers at the University of Oxford carried out whole-genome sequencing on isolates obtained from all symptomatic patients with C. difficile infection identified in healthcare settings or in the community in Oxfordshire, UK. By looking at the DNA, they constructed a family tree for each of the cases, based on the premise that those bugs with similar genetic codes were most likely to have come from the same source. This genetic information was combined with patient records to try and work out where the bug was coming from.
What the researchers found was that only 25% of hospital-associated C. diff infections were traced to contact with a symptomatic patient in one particular hospital system, and 45% of the cases were genetically distinct from all previous cases, suggesting genetically diverse sources – i.e., at large in the environment.
The study suggested that instead of encountering C. diff on entering the hospital, most patients carried it in with them. Then, it is believed that poor health and antibiotic treatment combine to encourage C. diff to overrun the intestines and cause disease.
It does not mean that good hygiene, antimicrobial technologies and deep cleaning are pointless, but it does suggest that these alone will not eradicate C. diff infections and that antibiotic usage needs refining.