Details

Autor(en) / Beteiligte

• Greenhalgh, Trisha
• Jimenez, Jose L
• Prather, Kimberly A
• Tufekci, Zeynep
• Fisman, David
• Schooley, Robert

Titel

Ten scientific reasons in support of airborne transmission of SARS-CoV-2

Ist Teil von

• The Lancet (British edition), 2021-05, Vol.397 (10285), p.1603-1605

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• Decades of painstaking research, which did not include capturing live pathogens in the air, showed that diseases once considered to be spread by droplets are airborne.4 Ten streams of evidence collectively support the hypothesis that SARS-CoV-2 is transmitted primarily by the airborne route.5 First, superspreading events account for substantial SARS-CoV-2 transmission; indeed, such events may be the pandemic's primary drivers.6 Detailed analyses of human behaviours and interactions, room sizes, ventilation, and other variables in choir concerts, cruise ships, slaughterhouses, care homes, and correctional facilities, among other settings, have shown patterns—eg, long-range transmission and overdispersion of the basic reproduction number (R0), discussed below—consistent with airborne spread of SARS-CoV-2 that cannot be adequately explained by droplets or fomites.6 The high incidence of such events strongly suggests the dominance of aerosol transmission. [...]long-range transmission of SARS-CoV-2 between people in adjacent rooms but never in each other's presence has been documented in quarantine hotels.7 Historically, it was possible to prove long-range transmission only in the complete absence of community transmission.4 Third, asymptomatic or presymptomatic transmission of SARS-CoV-2 from people who are not coughing or sneezing is likely to account for at least a third, and perhaps up to 59%, of all transmission globally and is a key way SARS-CoV-2 has spread around the world,8 supportive of a predominantly airborne mode of transmission. Some people have avoided SARS-CoV-2 infection when they have shared air with infected people, but this situation could be explained by a combination of factors, including variation in the amount of viral shedding between infectious individuals by several orders of magnitude and different environmental (especially ventilation) conditions.18 Individual and environmental variation means that a minority of primary cases (notably, individuals shedding high levels of virus in indoor, crowded settings with poor ventilation) account for a majority of secondary infections, which is supported by high-quality contact tracing data from several countries.19,20 Wide variation in respiratory viral load of SARS-CoV-2 counters arguments that SARS-CoV-2 cannot be airborne because the virus has a lower R0 (estimated at around 2·5)21 than measles (estimated at around 15),22 especially since R0, which is an average, does not account for the fact that only a minority of infectious individuals shed high amounts of virus.