Prevalence of the Clostridium difficile BI/NAP1/027 strain across the United States Veterans Health Administration

Abstract

ObjectivesThe increased incidence and severity of Clostridium difficile infection (CDI) are thought to result partly from the emergence of the hypervirulent BI/NAP1/027 strain. Limited recent data are available on the prevalence of BI/NAP1/027 in the United States (US). The objective of this study was to assess the recent prevalence of BI/NAP1/027 within the US Veterans Health Administration (VHA). MethodsPatients with CDI at any Veterans Affairs Medical Center found to routinely test for the presence of BI/NAP1/027 during the study period were included between 1 June 2011 and 30 June 2016 in this retrospective, observational, nationwide study. ResultsIn total, 7571 patients had 8224 positive C. difficile tests that had a corresponding BI/NAP1/027 test. Of those, there were 1810 (22.0%) presumptive positive for BI/NAP1/027. The overall prevalence of BI/NAP1/027 decreased from a high of 26.2% in 2013 to 16.9% in 2016. Statistically significant reductions in rates from 2012 to 2016 occurred in seven of nine US Census Bureau regions. ConclusionsThe prevalence of C. difficile with the BI/NAP1/027 strain was 22.0% across the VHA between 2012 and 2016. Further studies are needed to confirm these results and for continued monitoring of the trends in BI/NAP1/027 prevalence.