Breaking REVERSAL: @WHO has formally recognized that #COVID19 can be transmitted indoors by droplets in the AIR: people in crowded settings with poor ventilation run risk of being infected by the coronavirus as the droplets circulate via the air indoors.🧵
thehill.com/policy/healthc…
thehill.com/policy/healthc…
2) The admission comes after a crush of criticism from experts pushing the organization to update its description of the virus's spread to include the possibility of airborne infections.
3) WHO now acknowledges that transmissions via aerosols, or tiny air droplets, could have been behind "outbreaks of COVID-19 reported in some closed settings, such as restaurants, nightclubs, places of worship or places of work where people may be shouting, talking, or singing."
4) The WHO still mostly focuses on spread of the virus by larger droplets that are expelled through coughing, sneezing and singing or from contact with a contaminated surface.
➡️ This is still annoying.
➡️ This is still annoying.
5) "Respiratory droplet transmission can occur when a person is in close contact (within 1 metre) with an infected person who has respiratory symptoms (e.g. coughing or sneezing) or who is talking or singing”
⚠️hmm, not just someone showing symptoms- but pre/asymptomatic too.
⚠️hmm, not just someone showing symptoms- but pre/asymptomatic too.
6) “in these circumstances, respiratory droplets that include virus can reach the mouth, nose or eyes of a susceptible person and can result in infection," the agency writes.
7) “WHO had previously advised that airborne spread is only common when people, mostly HCWs, were involved in medical procedures that produce aerosols, though mounting evidence has surfaced suggesting that the virus can stay in the air for hours and infect a person when inhaled”
8) WHO report summarized that “Some outbreak reports related to indoor crowded spaces have suggested the possibility of aerosol transmission, combined with droplet transmission, for example, during choir practice, in restaurants or in fitness classes.” who.int/news-room/comm…
9) “Urgent high-quality research is needed to elucidate the relative importance of different transmission routes; the role of airborne transmission in the absence of aerosol generating procedures; the dose of virus required for transmission to occur”
10) Face mask req: “Use fabric masks in specific situations, for example, in public places where there is community transmission and where other prevention measures, such as physical distancing, are not possible”
11) “At all times... wear fabric masks when in closed, overcrowded spaces to protect others; and ensure good environmental ventilation in all closed settings and appropriate environmental cleaning and disinfection.” ⚠️
12) My reaction- WHO kinda half reversed the airborne stance - it now recognizes it as possible but says it doesn’t know how big a deal it is, and then seems to favor droplets as the main mode. Hmmm welcome thoughts @jljcolorado, one of the 239 aerosol letter researchers.
13) Here is a great piece in the NYTimes on this. nytimes.com/2020/07/09/hea…
