Detection and quantification of airborne norovirus during outbreaks in healthcare facilities

Noroviruses are responsible for at least 50% of all gastroenteritis outbreaks worldwide. Noroviruses GII can infect humans via multiple routes including direct contact with an infected person, contact with fecal matter or vomitus, and with contaminated surfaces. Though norovirus is an intestinal pathogen, aerosols could, if inhaled, settle in the pharynx and later be swallowed. The aims of this study were to investigate the presence of norovirus GII bioaerosols during gastroenteritis outbreaks in healthcare facilities as well as studying the in vitro effects of aerosolization and air sampling on the noroviruses using murine norovirus as a surrogate.Methods. A total of 48 air samples were collected during norovirus outbreaks in 8 healthcare facilities. Samples were taken 1 m away from each patient, in front of the patient's room and at the nurses' station. The resistance to aerosolization stress of murine norovirus MNV-1 bioaerosols was also tested in vitro using an aerosol chamber.Results. Norovirus genomes were detected in 6/8 healthcare centers. The concentrations ranged from 1.35x101 to 2.35x103 genomes per m3 in 47% of air samples. Norovirus MNV-1 preserved its infectivity and integrity during in vitro aerosol studies.Conclusion. Norovirus genomes are frequently detected in the air of healthcare facilities during outbreaks, even outside patients' rooms. In addition, in vitro models suggest this virus may withstand aerosolization.

Detection and quantification of airborne norovirus during outbreaks in healthcare facilities. Clinical Infectious Diseases . JOUR. http://doi.org/10.1093/cid/civ321