I have been receiving Qs about why overestimating asymptomatic infections might misinform policy.
1/ Most importantly it endangers finding the best strategies controlling the epidemic and it also understates other aspects that are important in transmission dynamics
1/ Most importantly it endangers finding the best strategies controlling the epidemic and it also understates other aspects that are important in transmission dynamics
2/ We need to find out where the majority of transmission is occurring & who transmits the most so that we can strategically direct our control measures, and this could also inform contact tracing and testing efforts.
3/ Some may wish to assume everyone and every environment have the same risk of transmission, but we know that it is not the case. Looking at contact tracing studies, not all activities, environments pose the same risk for transmission.
japantimes.co.jp
japantimes.co.jp
4/ For example, when we look at some superspreading events, they are linked to mildly symptomatic individuals attending crowded indoor events. They are not asymptomatic/presymptomatic but have aches, runny nose, sore throat, but otherwise feel well
bbc.co.uk
bbc.co.uk
5/ A major problem with the current literature is that many studies mislabel those individuals with mild symptoms as either presymptomatic or asymptomatic. But respiratory symptoms or fever do not cover the spectrum of COVID-19 presentations
zenodo.org
zenodo.org
6/ Besides, what we know so far is that transmission depends on many factors: person, environment, activity, duration of contact. For instance, care homes, hospitals, prisons are a very different context than brief community contact.
vox.com
vox.com
7/ And many studies suggest that the environment has a greater influence on transmission dynamics. I spoke to @Mikepeeljourno here about which environments pose the highest risk, with great data visuals from @jburnmurdoch
@FinancialTimes
ft.com
@FinancialTimes
ft.com
8/ So, in this argument, asymptomatic spread, esp if contributing very little, may have a minimal influence driving the pandemic. We may be able to avert the majority of infections by finding and isolating those with mild symptoms who otherwise feel well & avoiding indoor crowds.
9/ Ultimately we need to learn how to live with the virus in the long run. So knowing which environments/activities pose the greater risk is important. I discussed with @RoniNYTimes in this @nytimes article how to navigate your risk
nytimes.com
nytimes.com
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