A newly published study by medical researchers from the UK suggests that most reported cases of human infection by Clostridium difficile are not acquired in hospital, but from sources in the community, including animals.
The study was conducted in Oxfordshire from September 2007 to March 2011 and the researchers examined C. difficile isolates from symptomatic patients using whole-genome sequencing to identify genetically related isolates and epidemiological links between them. More than 1200 isolates were successfully sequenced.
The results indicated that the incidence of infections fell during the study period, suggesting that interventions designed to reduce transmission of infection in hospitals had been partially successful. However, the sequencing results suggested a large reservoir of infection from a number of genetically diverse sources. Only about 18% of the cases examined were transmitted from patient to patient in hospital.
The findings suggest that exposure to C. difficile in the community is widespread. One of the research team, Professor Tim Peto, is quoted in a BBC news report thus, “I think we’re eating it all the time, probably from animals, and most of us get it and it doesn’t matter.” C. difficile infection does not usually cause symptoms in healthy people, but can be very serious for the elderly, especially those being treated with antibiotics.
A report of the study is published in the New England Journal of Medicine and an abstract can be found here.