Evaluating Strain Variations in Routes of Clostridium difficile Infections (CDI)

Clostridium difficile is an anaerobic spore-forming, gram-positive bacillus that is frequently implicated in antibiotic-associated diarrhea and infection, especially among hospitalized patients C. difficile infection (CDI) has emerged as a global concern as the incidence of disease and mortality around the world appear to be increasing. These strains are resistant to different antibiotics rendering treatment ineffective. For those who already have comorbidities, CDI infections present a greater risk of adverse health outcomes and mortality. The presentation of CDI shows different strain type involvements depending on location. Numerous studies have assessed the strain variation and risk factors for these unfavorable outcomes, but systematic reviews published have been limited in scope, restricted to certain locations, or lacking in quality. A systematic review was completed to evaluate which of the following exposure-to-development routes was most prevalent for CDI along with determining which strains appear as drivers for the different routes of infections. Most common route is hospital-acquired and hospital-onset while most common strain types are RT027, RT001, and RT017. Given the varying case definitions and outcome measurements, these studies are limited in fully measuring the association of CDI to exposure in either community or hospital settings. In addition, sampling from hospital settings presents specific biases (e.g. Berkson\u27s bias, survivorship bias) that can affect the true associations measured. This review has found some differences in strains that manifest in community or hospital settings. Exposure-to-development routes still are not fully understood, and more focus should be placed on understanding how C. difficile is transmitted and develops into CDI