Reducing rates of Clostridium difficile infection by switching to a stand-alone NAAT with clear sampling criteria

Clostridium difficile infection is an important cause of morbidity and mortality but the optimal method of diagnosis for both patient management and infection prevention remains controversial.

Our hospital made a decision to switch from the use of toxin immunoassay to a stand-alone nucleic acid test. This change was accompanied by the provision of clear sampling guidance and rejection criteria and this study aimed to assess the impact of that change. We analysed sample numbers, numbers of positive results, and the proportion of cases assessed as healthcare acquired over a 6-year period during which the testing method was changed from a toxin A/B immunoassay to a stand-alone commercial nucleic acid test after the first two years.

Sample numbers and numbers of cases assessed as healthcare acquired fell following the introduction of the nucleic acid test and sampling guidance, while infection rates in other hospitals in the same region remained relatively stable.

It is our opinion that the use of a highly sensitive assay together with clear sampling guidance offers the optimal approach to patient management and best use of isolation facilities.