However, new,
more
virulent
strains
of C. difficile emerged in the early 1990s, associated
with broader antibiotic resistance, greater capacity for toxin production, and increased sporulation efficiency [7–9]. This has
been
accompanied by greater incidence, morbidity, and mortality
associated
with CDI. CDI today is the most common cause of nosocomial
diarrhea in the US, and has increasingly become an important
cause
of community-acquired diarrhea [10,11]. Although the Centers
for Disease Control conservatively attributes approximately
14,000
deaths to CDI annually, some estimates of CDI-associated
mortality
are >100,000 per year [12].