7f - Evaluation of the surveillance system for severe Clostridioides difficile infections in Germany 2017-2022, a mixed methods approach

Background : Severe Clostridioides difficile infections (sCDI) are notifiable by physicians to local public health authorities (PHA) and further reported to state PHA and national level in Germany. We aimed at evaluating sCDI surveillance regarding timeliness, completeness, representativeness, acceptability, simplicity and usefulness to adjust as necessary.

Methods : Using national sCDI surveillance data from 01.01.2017–31.12.2022 we assessed timeliness, using median and interquartile range (IQR) for notification delay (date of diagnosis to date of notification) and reporting delay (local PHA to national level reporting, working days). We assessed completeness calculating percentages of available information for selected variables. Assessing representativeness, we compared incidences over time and age and sex distribution of notified cases with public databases (hospital surveillance, federal death cause and hospital discharge diagnoses monitoring, and state level notification data from Saxony for severe and non-severe cases). We conducted semi-structured interviews with PHA to understand their experiences of the system’s acceptability, simplicity and usefulness, applying qualitative thematic analysis.

Results : Altogether, 12,399 sCDI cases were reported to national level. Median notification and reporting delay were 4 days (IQR=1;9) and 1 working day (IQR=0;2), respectively. Completeness was sex=100%;12,397/12,399, age=100%;12,397/12,399, disease onset date=86%;10,709/12,399, hospitalization=98%;12,107/12,399, intensive care treatment=88%;10,891/12,399. Incidences over time and age and sex distribution were comparable between different databases. Main challenges identified through eight interviews were complex notification criteria (simplicity), low physician compliance and low perceived relevance (acceptability) and low usefulness in identifying epidemiological links.

Conclusions While the system offers timely, complete, and representative data, it is perceived as complex, lacking acceptability, and having limited usefulness. More detailed information for PHA on notification criteria and training of physicians on notification processes is needed. The findings will guide possible revision of sCDI notification in Germany.