Characteristics of airborne micro-organisms in a neurological intensive care unit: Results from China

Objective To describe the characteristics of airborne micro-organisms in the environment in a Chinese neurological intensive care unit (NICU). Methods This prospective study monitored the air environment in two wards (large and small) of an NICU in a tertiary hospital in China for 12 months, using an LWC-1 centrifugal air sampler. Airborne micro-organisms were identified using standard microbiology techniques. Results The meanSD number of airborne bacteria was significantly higher in the large ward than in the small ward (200 +/- 51colony-forming units [CFU]/m(3) versus 110 +/- 40CFU/m(3), respectively). In the large ward only, the mean number of airborne bacteria in the autumn was significantly higher than in any of the other three seasons. A total of 279 airborne micro-organisms were identified (large ward: 195; small ward: 84). There was no significant difference in the type and distribution of airborne micro-organisms between the large and small wards. The majority of airborne micro-organisms were Gram-positive cocci in both wards. Conclusion These findings suggest that the number of airborne micro-organisms was related to the number of patients on the NICU ward.