Role of intensive care unit environment and health-care workers in transmission of ventilator-associated pneumonia.

BACKGROUND Pseudomonas aeruginosa and Acinetobacter baumannii have been reported to cause outbreaks of ventilator-associated pneumonia (VAP) in several studies. The high prevalence of these pathogens prompted us to study the different strains of these pathogens prevailing in our intensive care units (ICUs) and determine the role of ICU environment and health-care workers (HCWs) in the transmission of infection. METHODOLOGY A prospective study was performed over a period of 15 months in two ICUs of Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India. Surveillance samples were collected from the HCWs and the ICU environment. Quantitative antibiogram typing and PCR-RFLP were used for comparison of the isolates from the surveillance samples and VAP patients. RESULTS Pseudomonas aeruginosa and Acinetobacter baumannii were the most common potential VAP pathogens isolated from the surveillance cultures. Eight strains of Pseudomonas aeruginosa were present in our ICUs, but multi-drug resistant (MDR) strain 2 and strain 4 were the most prevalent strains. Six strains of Acinetobacter baumannii were found in our ICUs, of which MDR strain 1 and strain 3 were the most common. The strains of Pseudomonas aeruginosa and Acinetobacter baumannii observed in the VAP patients were also found in the ICU milieu. Only one HCW was found to be the carrier of a Pseudomonas aeruginosa strain present in a VAP patient. CONCLUSIONS The ICU environment was observed to be the potential reservoir for VAP pathogens; therefore, strict adherence to environmental infection control measures is essential to prevent health-care-associated infections.