New insights into transmission of Clostridium difficile infection-narrative review.

BACKGROUND: Traditionally, Clostridium difficile has been considered a typical healthcare-associated pathogen-that is, one transmitted within healthcare facilities and thus prevented by implementation of standard infection control measures. Recently this concept has been challenged by studies suggesting a relevant role for community acquisition of C. difficile.

AIMS: To discusses the current literature, compiled during the last decade, reporting on sources of acquisition of C. difficile and subsequent transmission.

SOURCES: The databases PubMed, Medline, Embase and the Cochrane Database were searched for articles published from 1 January 2007 to 30 June 2017 reporting on possible transmission pathways of C. difficile and/or suggesting a source of acquisition of C. difficile. All study types reporting on adult populations were considered; case reports and series were excluded. The PRISMA guidelines for the reporting of systematic reviews were followed.

CONTENT: Among 24 original articles included, 63% report on transmission of C. difficile in healthcare settings and 37% investigate sources and transmission of C. difficile in the community. Contact with symptomatic carriers (53.3%), the hospital environment (40.0%) and asymptomatic carriers (20%) were the most commonly reported transmission pathways within healthcare settings. The leading sources for acquisition of C. difficile in the community include direct contact with symptomatic and asymptomatic carriers in the community, including infants (30%) and residents of long-term non-acute care facilities (30%), followed by contact with contaminated environments in outpatient care settings (20%) and exposure to livestock or livestock farms (20%).

IMPLICATIONS: In healthcare settings, future control efforts may need to focus on extending cleaning and disinfection procedures beyond the immediate surroundings of symptomatic carriers. Potential targets to prevent acquisition of C. difficile in the community include household settings, long-term care facilities and outpatient settings, while the role of livestock in entertaining transmission requires further investigation.