This project aims to estimate the incidence of C. difficile infection in Oxfordshire, inside and outside hospitals (inpatient, outpatient/day case/A&E, community), over calendar time, analysing the trends to identify potential new strains (as measured by multi-locus sequence type, MLST) threatening the health of Oxfordshire residents. We will also explore whether and how outcomes following C. difficile infection, might be changing, particularly in terms of mortality and changes in laboratory test results. We will then compare the impact of different C. difficile strains (by MLST) on different outcomes, including mortality, admission to ITU, and laboratory tests such as C-reactive protein, and numbers of cells which fight infections (white cells, lymphocytes, neutrophils), in order to identify whether there are specific strains that are more likely to be associated with poor outcomes that we should be particularly looking out for. We will adjust for important demographic (age, sex) and hospital-associated factors (speciality, admitted as emergency/elective, admission speciality, duration and type of previous hospital exposure including days since current admission, number of previous admissions, total prior hospital stay, time since last discharged, previous isolation of S. aureus or C. difficile).
Summary of findings: We found that Clostridium difficile genotype predicts 14-day mortality in 1893 EIA-positive-culture-positive adults. Excess mortality correlates with genotype-specific changes in biomarkers, strongly implicating inflammatory pathways as a major influence on poor outcome. PCR-ribotype-078/ST-11(clade 5) is associated with high mortality; ongoing surveillance remains essential.