Strong evidence coronavirus predominantly spreads through air: Lancet

A new assessment in the medical journal Lancet has found consistent strong evidence that the SARSCoV2 virus which causes COVID19 is predominantly transmitted through the airTherefore public health measures that fail to treat the virus as predominantly airborne leave people unprotected and allow the virus to spread according to six experts from the UK USA and Canada including JoseLuis Jimenez a chemist at the Cooperative Institute for Research in Environmental Sciences CIRES and the University of Colorado BoulderThe evidence supporting airborne transmission is overwhelming and evidence supporting large droplet transmission is almost nonexistent Jimenez said It is urgent that the World Health Organization and other public health agencies adapt their description of transmission to the scientific evidence so that the focus of mitigation is put on reducing airborne transmissionThe team of experts led by the University of Oxfords Trish Greenhalgh reviewed published research and identified 10 lines of evidence to support the predominance of the airborne routeAt the top of their list Superspreader events such as the Skagit Choir outbreak in which 53 people became infected from a single infected case Studies have confirmed these events cannot be adequately explained by close contact or touching shared surfaces or objectsMoreover transmission rates of SARSCoV2 are much higher indoors than outdoors and transmission is greatly reduced by indoor ventilationThe team highlighted research estimating that silent asymptomatic or presymptomatic transmission of SARSCoV2 from people who are not coughing or sneezing accounts for at least 40 per cent of all transmission This silent transmission is a key way COVID19 has spread around the world supporting a predominantly airborne mode of transmission according to the assessment The researchers also cited work demonstrating longrange transmission of the virus between people in adjacent rooms in hotels people who were never in each others presenceBy contrast the team found little to no evidence that the virus spreads easily via large droplets which fall quickly through the air and contaminate surfacesWe were able to identify and interpret highly complex and specialist papers on the dynamics of fluid flows and the isolation of live virus lead author Greenhalgh said While some individual papers were assessed as weak overall the evidence base for airborne transmission is extensive and robust There should be no further delay in implementing measures around the world to protect against such transmissionThe new work has serious implications for public health measures designed to mitigate the pandemic First droplet measures such as handwashing and surface cleaning while not unimportant should be given less emphasis than airborne measures which deal with inhalation of infectious particles suspended in the airIf an infectious virus is primarily airborne someone can potentially be infected when they inhale aerosols produced when an infected person exhales speaks shouts sings or sneezes So airborne control measures include ventilation air filtration reducing crowding and the amount of time people spend indoors wearing masks whenever indoors even if not within 6 feet or 2 meters of others attention to mask quality and fit and highergrade PPE for healthcare and other staff when working in contact with potentially infectious peopleIt is quite surprising that anyone is still questioning whether the airborne transmission is the predominant transmission pathway for this virus or not said coauthor Professor Kimberly Prather an aerosol scientist from the University of California San Diego Only by including inhalation of aerosols at both close and long range can we explain the many indoor outbreaks that have occurred around the globe Once we acknowledge this virus is airborne we know how to fix it There are many examples of places that have fared much better by acknowledging this virus is airborne from the start The world needs to follow their lead as soon as possibleThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever