Six-step transmission cascade of C. auris from gastrointestinal colonization to outbreak propagation, with associated IPC containment levers.

Table 1: Six-step transmission cascade of C. auris from gastrointestinal colonization to outbreak propagation, with associated IPC containment levers.

Step in the transmission cascade	Mechanism	Containment lever
1. Gastrointestinal colonization	C. auris colonizes the GI tract, creating a stool reservoir that becomes the primary source of environmental contamination	Active surveillance (rectal swab, stool culture)
2. Stool leakage and surface seeding	Uncontrolled fecal effluent contaminates mattresses, bedding, gowns, floors, and adjacent equipment	Closed-loop fecal diversion
3. Environmental persistence	C. auris survives on patient-zone surfaces for days to weeks; resists routine disinfectants	Bleach- or quat-based EPA List P/K disinfection
4. Contamination of staff and equipment	Organism transfers to gloves, hands, and shared mobile equipment during repositioning, perineal care, and linen changes	Contact precautions; dedicated equipment
5. Cross-transmission to vulnerable patients	Susceptible hosts in shared ICU and LTACH environments acquire C. auris via contaminated surfaces or hands	Cohorting; horizontal hand hygiene
6. Outbreak propagation	Persistent reservoirs, frequent patient-staff contacts, and population vulnerability sustain transmission clusters	Multimodal IPC bundle including source containment

IPC: infection prevention and control. EPA List P/K refers to Environmental Protection Agency–registered antimicrobial products effective against C. auris. Adapted from refs. [1,5,8,9]