Small quantities of respiratory syncytial virus RNA only in large droplets around infants hospitalized with acute respiratory infections

Abstract

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.

SARS-CoV-2 viral load and shedding kinetics

“…In human challenge trials, respiratory syncytial virus titres were detectable for an average of 4.6 days. Viral RNA could be still detected up to 9 dpos, whereas infectious virus titres could be detected from 1 to 8 dpos in adults 208 and up to 9 dpos in children 209 .…”

Tryptophan-like side chain holding aptamers inhibit respiratory syncytial virus infection of lung epithelial cells

“…The non-biotinylated strands were separated from the immobilized complementary strand by 10 min incubation with 50 μl of fresh 20 mM NaOH. The eluted ssDNA was immediately neutralized by addition of 7.5 μl of 200 mM NaH 2 PO 4 . In the following rounds of selection, the postfusion form of F protein was used either coupled to paramagnetic beads as a counter-target molecule (in rounds no.…”

“…It is made available under a preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in The copyright holder for this this version posted December 9, 2022. ; https://doi.org/10.1101/2022.12.09.519757 doi: bioRxiv preprint 2 and spreads among groups of young children, within families and between hospitalized patients via direct physical contact, droplets and aerosol transmission. 4,5 Currently there is no licensed vaccine available to prevent RSV infections, while many vaccine candidates are under development. The only approved prophylaxes are monoclonal antibodies directed against F protein.…”

“…3 RSV is a highly contagious pathogen and spreads among groups of young children, within families and between hospitalized patients via direct physical contact, droplets and aerosol transmission. 4,5 Currently there is no licensed vaccine available to prevent RSV infections, while many vaccine candidates are under development. The only approved prophylaxes are monoclonal antibodies directed against F protein.…”

“…RSV is a highly contagious pathogen and spreads among groups of young children, within families and between hospitalized patients via direct physical contact, droplets and aerosol transmission (5,6).…”