What are the typical sources of Enterobacter cloacae in healthcare settings and what infection‑control precautions should be implemented?

Enterobacter cloacae Sources and Infection Control

Primary Sources in Healthcare Settings

Enterobacter cloacae is primarily an endogenous pathogen originating from patients' own intestinal flora, with transmission occurring predominantly through contaminated hands of healthcare workers and environmental surfaces. 1, 2

Patient-Related Sources

• Gastrointestinal colonization is the most common reservoir, as E. cloacae is part of normal intestinal microbiota in many individuals 2
• Maternal-to-neonatal vertical transmission can occur during delivery, with intestinal colonization of neonates documented 3
• Patients who have received prior antimicrobial therapy or ICU admission are at highest risk for developing invasive infection 1

Environmental Reservoirs

• High-touch surfaces in patient rooms including bed rails, doorknobs, bedside tables, washbasins, and window sills serve as contamination sites 4
• Medical equipment and devices that contact multiple patients 4
• Moist environments where the organism can persist 5

Healthcare Worker Transmission

• Contaminated hands represent the primary vector for cross-transmission between patients 4, 6
• Inadequate hand hygiene compliance, particularly when sink access is limited, facilitates spread 4

Infection Control Precautions

Hand Hygiene (Cornerstone Intervention)

Implement rigorous hand hygiene with alcohol-based hand rub before and after all patient contacts, switching to soap and water when hands are visibly soiled. 4, 6

• Alcohol-based hand rub is the preferred method for routine hand antisepsis 6
• Soap and water must be used when hands are visibly contaminated with body fluids 4, 6
• Monitor compliance and provide feedback to healthcare workers to achieve adherence 6
• Prohibit artificial nails among healthcare workers 6

Contact Precautions

Place colonized or infected patients under contact precautions with single-room isolation when possible. 4, 6

• Healthcare workers must wear gloves and gowns before entering rooms of colonized/infected patients 6
• Implement alert codes to identify previously colonized patients at hospital/ward admission 4
• Apply pre-emptive contact precautions for patients transferred from ICUs or wards with known E. cloacae cases 4

Patient Isolation and Cohorting

• Isolate patients in single rooms to reduce acquisition risk, monitoring for potential adverse effects of isolation 4
• When single rooms are unavailable, cohort patients with the same E. cloacae strain in designated areas 4
• Consider cohorting dedicated staff to colonized patient areas 4

Environmental Cleaning and Disinfection

Implement enhanced environmental cleaning with EPA-registered hospital disinfectants, focusing on high-touch surfaces with audit and feedback mechanisms. 4

High-Priority Surfaces

• Clean doorknobs, bed rails, light switches, bedside tables, and surfaces in/around toilets more frequently than minimal-touch surfaces 4
• Dedicate non-critical patient-care equipment to single patients or cohorts when possible 4

Cleaning Protocols

• Use EPA-registered hospital detergent/disinfectant in patient-care areas where uncertainty exists regarding surface contamination 4
• Prepare cleaning solutions daily and replace frequently per facility policy 4
• Change mop heads at the beginning of each day and after large spills 4
• Clean mops and cloths after use and allow complete drying before reuse, or use single-use disposable materials 4
• Perform environmental sampling from surfaces that contacted colonized/infected patients 4

Critical Cleaning Practices

• Keep housekeeping surfaces visibly clean and clean spills promptly 4
• Avoid large-surface cleaning methods that produce mists, aerosols, or disperse dust 4
• Do not perform disinfectant fogging in patient-care areas 4
• Consider ward closure to new admissions during outbreaks to facilitate intensive cleaning 4

Active Surveillance and Screening

Implement active screening cultures at hospital admission followed by contact precautions to reduce colonization rates, particularly in high-risk units. 4, 6

• Screen patients at admission in units with ongoing transmission 4
• Use stool samples or rectal swabs for screening cultures 4
• Screen healthcare workers only if epidemiologically linked to a cluster of cases 4

Education and Administrative Support

Conduct educational programs ensuring healthcare workers understand E. cloacae epidemiology, transmission prevention, and effective control measures. 4, 6

• Hold regular multidisciplinary meetings to implement interventions and review adherence audits 4, 6
• Provide local data feedback to all healthcare workers and relevant staff 4, 6
• Establish administrative support including economic and human resources for infection control 6

Antimicrobial Stewardship

Implement antimicrobial stewardship programs with restriction of antibiotic usage to reduce E. cloacae spread, particularly limiting AmpC-inducing beta-lactams. 4, 6

• E. cloacae possesses chromosomally-induced AmpC β-lactamase with multidrug-resistant potential 7
• Prior antimicrobial therapy is a major risk factor for E. cloacae infection 1

Special Considerations for Neonatal Units

Neonatal units require heightened vigilance due to E. cloacae's emergence as a common pathogen in these settings. 5, 3

• Nurse-to-patient ratios significantly impact cross-transmission rates (1:2 ratios show lower transmission than 1:4) 5
• Alcohol-based hand rub consumption correlates inversely with transmission rates 5
• Community-acquired E. cloacae infection can occur in neonates through vertical transmission, requiring appropriate empiric antimicrobial coverage 3

Common Pitfalls to Avoid

• Do not rely solely on alcohol-based hand sanitizers when caring for patients with enteric organisms; soap and water physically removes organisms 4, 6
• Avoid inadequate environmental cleaning as E. cloacae persists on surfaces; ensure proper contact time for disinfectants 4
• Do not overlook asymptomatic carriers who contribute to environmental contamination and cross-transmission 5
• Avoid premature discontinuation of contact precautions without documented clearance in outbreak settings 4