Background: Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in young children. The predominant transmission routes for RSV are still a matter of debate. Specifically, it remains unclear if RSV can be transmitted through the air and what the correlation is between the amount of RSV in nasopharynx samples and in the air. Methods: The amount of RSV in the air around hospitalized RSV infected infants in single-patient rooms was quantified using a six-stage Andersen cascade impactor that collects and fractionates aerosols and droplets according to size. RSV shedding in the nasopharynx of patients was followed longitudinally by quantifying RSV RNA levels and infectious virus in nasopharyngeal aspirates. Nose and throat swabs of parents and swabs of the patient’s bedrail and a datalogger were also collected. Results: Patients remained RSV positive during the air sampling period and infectious virus was isolated up to 9 days post onset of symptoms. In three out of six patients, low levels of RSV RNA, but no infectious virus, were recovered from impactor collection plates that capture large droplets > 7 μm. For four of these patients, one or both parents were also positive for RSV. All surface swabs were RSV-negative. Conclusions: Despite the prolonged detection of infectious RSV in the nasopharynx of patients, only small amounts of RSV RNA were collected from the air around three out of six patients, which were primarily contained in large droplets which do not remain suspended in the air for long periods of time.
Bibliographical noteFunding Information:
This work was financed through an NWO VIDI (contract number 91715372) to SH and EU FP7 project PREPARE (602525). RAMF and SH were funded in part by the NIH/NIAID (contract HHSN272201400008C). PLAF and SH were funded in part by ZonMW (Netherlands Organization for Health and research development) Program 10430022010024. The funders had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.
© 2021, The Author(s).