Transmission of Acinetobacter baumannii
Acinetobacter baumannii can spread through droplet transmission in intensive care unit settings and during aerosol-generating procedures, in addition to its primary mode of transmission through direct and indirect contact. 1
Primary Modes of Transmission
- A. baumannii primarily spreads through direct contact with infected or colonized patients and indirect contact via contaminated surfaces, equipment, and healthcare workers' hands 1
- Environmental contamination plays a significant role in transmission, as A. baumannii can persist on surfaces for extended periods 1, 2
- Healthcare workers' hands are the predominant mode of transmission, emphasizing the critical importance of hand hygiene 1
Droplet Transmission
- European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines specifically recommend considering droplet precautions when entering rooms of patients colonized or infected with MDR-A. baumannii in ICU settings 1
- Droplet precautions are also recommended during all aerosol-generating procedures for A. baumannii 1
- Evidence shows that A. baumannii can be aerosolized in intensive care unit environments 1
Infection Control Implications
- Contact precautions must be implemented for all patients with A. baumannii infection or colonization (strong recommendation) 1
- Healthcare workers should wear gloves and gowns before entering the room of colonized/infected patients and remove them promptly after care 1
- Single room isolation is strongly recommended to reduce transmission risk 1
- Consider droplet precautions (use of a mask) for ICU patients and during aerosol-generating procedures 1
Environmental Control Measures
- Thorough environmental cleaning and disinfection are essential components of A. baumannii control 1
- Sodium hypochlorite solutions (0.5%) are recommended for effective environmental decontamination 1
- Dedicated equipment should be used for patients infected or colonized with A. baumannii 1
- Monitor cleaning performance to ensure consistent environmental cleaning 1
Surveillance and Prevention
- Regular screening of high-risk patients is recommended, especially in outbreak situations 1
- Screening should include samples from rectum/perirectal area, inguinal area, and manipulated sites 1
- Alert systems should be implemented to promptly identify previously colonized or infected patients 1
- Antibiotic stewardship programs are essential to reduce selection pressure for resistant strains 1
Key Differences from Other Pathogens
- Unlike true airborne pathogens (e.g., measles virus, tuberculosis), A. baumannii's airborne transmission is limited to droplet spread over short distances 1
- A. baumannii has remarkable environmental persistence compared to many other healthcare-associated pathogens, contributing to its transmission potential 1, 2
- Some A. baumannii clinical isolates have recently been found to establish intracellular niches, potentially contributing to persistence and treatment challenges 3
Common Pitfalls in Infection Control
- Underestimating the importance of environmental cleaning can lead to persistent contamination and ongoing transmission 1
- Failure to implement droplet precautions in ICU settings may increase transmission risk 1
- Inconsistent hand hygiene compliance remains a major challenge in controlling A. baumannii spread 1
- Delayed recognition of colonized patients can facilitate silent spread throughout healthcare facilities 1