Abstract
Introduction: RSV is a highly contagious pathogen and spreads among groups of young children, within families and between patients in hospital. RSV is thought to spread predominantly by hands contaminated with infectious respiratory secretions [1]. However, it remains unclear if RSV can be spread by aerosol. Knowledge of this is important as it is assumed in many hospitals that aerosol transmission of RSV does not occur.
Aim: To determine if patients with RSV bronchiolitis produce aerosolised particles containing RSV capable of infecting human respiratory epithelial cells (A549).
Method: 18 infants with “RSV Bronchiolitis” were recruited. An Andersen microbial impactor was placed 100cm from the head of the patient and run for 30min fractionating collected particles into different aerosol size distributions. Room air was impacted into 20ml of RPMI growth media and its infectivity of A549 was determined using plaque assays. Immunofluorescence staining of the infected A549 cells was used to confirm RSV infection.
Results: 17 infants produced infectious airborne particles less than 4.7μ. We estimated the number of infectious RSV within aerosols of less than 4.7μ produced from 12/17 patients to be 188.5±68 (mean ± SEM, range 2.4 to 4044) in 10 litres of air. This volume would be inhaled by a 3.1kg baby in 10 minutes (respiratory rate 40/min; tidal volume 8ml/kg).
Conclusion: Infants with RSV bronchiolitis produce aerosols that contain infectious RSV in aerosols small enough to deposit in the lower airways. These findings may influence infection control strategies to prevent aerosol transmission of RSV in a hospital setting.
Reference:
1. Goldmann DA. Pediatric Infectious Disease Journal 2000;19(10 Suppl).
- © 2011 ERS
