How does Acinetobacter baumannii spread?

Transmission of Acinetobacter baumannii

Acinetobacter baumannii primarily spreads through healthcare workers' hands, contaminated hospital environments, and medical equipment, requiring strict infection control measures including hand hygiene, environmental cleaning, and patient isolation to prevent transmission. 1

Primary Transmission Routes

• Healthcare workers' hands: The majority of A. baumannii transmission events occur via healthcare workers' hands, making hand hygiene of paramount importance in preventing spread 1
• Environmental contamination: A. baumannii can survive for prolonged periods on hospital surfaces, equipment, and medical devices, serving as reservoirs for ongoing transmission 2, 3
• Patient-to-patient transmission: Can occur directly or indirectly through shared equipment, surfaces, or healthcare worker contact 1

High-Risk Areas and Surfaces

• Intensive care units (ICUs): Highest concentration of A. baumannii infections occurs in ICUs, particularly in internal medicine and burns units 4, 2
• High-touch surfaces: Bed rails, sinks, food tables, trolley handles, ventilator inlets, door handles, light switches, and medical equipment are frequently contaminated 2
• Medical devices: Biofilm formation on devices like ventilators and catheters facilitates persistent colonization and infection 4

Factors Facilitating Transmission

• Biofilm formation: A. baumannii can form biofilms on both biotic and abiotic surfaces, enhancing its survival and resistance to disinfection 4
• Environmental persistence: The pathogen can survive for extended periods on hospital surfaces, facilitating its spread 3, 5
• Antimicrobial resistance: Multi-drug resistant strains are more difficult to eradicate, leading to prolonged colonization and increased transmission risk 2, 5

Prevention Strategies

Hand Hygiene

• Strict adherence to hand hygiene protocols using appropriate antiseptic solutions (chlorhexidine/alcohol) before and after patient contact 1, 6
• Regular monitoring and feedback on hand hygiene compliance 7

Patient Isolation and Cohorting

• Single rooms are preferable for colonized/infected patients 1
• If single rooms are unavailable, cohort patients with the same organism together 1
• Implement contact precautions for all patients with confirmed or suspected A. baumannii 1

Environmental Cleaning and Disinfection

• Regular and thorough cleaning of patient rooms and high-touch surfaces 1
• Use of 0.5% hypochlorite solutions for surface cleaning 1
• Specific protocols for cleaning medical equipment with clear responsibilities assigned 1

Active Surveillance

• Weekly screening of all patients during outbreaks using rectal and pharyngeal swabs, plus tracheal secretions in ventilated patients 1
• Use of chromogenic media for rapid identification of MDR A. baumannii 1
• Implementation of alert codes to promptly identify patients known to be colonized or infected 1

Antimicrobial Stewardship

• Implementation of antibiotic stewardship programs to reduce selection pressure for resistant strains 1, 7
• Rational use of broad-spectrum antibiotics, particularly carbapenems 1

Special Considerations for Outbreaks

• Immediate implementation of infection control measures upon detection of a single case in an area with no previously identified cases 1
• Epidemiologic investigation when MDR, XDR, or PDR A. baumannii cases appear or increase 1
• Consider temporary closure of affected wards in severe outbreaks 1
• Obtain institutional and administrative support for infection control initiatives 1

Endemic Situations

• Implementation of multifaceted interventions including education, antibiotic stewardship, hand hygiene reinforcement, contact precautions, environmental cleaning, and targeted surveillance 1
• Active screening at ICU admission with pre-emptive contact precautions until negative results are confirmed 1
• Molecular typing to determine strain relatedness and transmission pathways 1

By understanding and addressing these transmission pathways through comprehensive infection control measures, healthcare facilities can significantly reduce the spread of A. baumannii and its associated morbidity and mortality.