Risk of secondary cases of C. difficile in households doesn't justify interventions

The risk of Clostridium difficile infection (CDI) among households is too low to justify interventions, other than avoiding unnecessary antimicrobials, according to a new study published in April’s Journal of Infection.

The research was led by Jacques Pepin with the University of Sherbrooke in Sherbrooke, Quebec, Canada. According to the authors, it is the first study exploring CDI person-to-person transmission to this extent.

“The strength of the study resides in our ability to detect exhaustively all cases of CDI within a large population over more than a decade, during which a gold standard diagnostic assay…was used,” they stated.

Researchers reviewed more than 2,200 patients with confirmed CDI in a region of Quebec from 1998 to 2009. They found that 1,061 spouses and 501 children, including adult children (aged 25 years or younger), lived in the same household as the index cases. Five spouses and 3 children developed CDI for the 3 months after the diagnosis of the index case (RR=7.61; 95% CI: 5.77–9.78, for adults, and RR=90.6; 95% CI: 33.89–487.64, for children).

Most likely, a vast majority of household contacts do not receive an antimicrobial agent during the period when they might be colonized with a C. difficile strain from a relative, the authors said.

“Although the relative risk of CDI among household contacts is somewhat increased for a few months, the absolute risk is too low to justify interventions, apart from avoiding unnecessary courses of antimicrobial agents,” the authors said.