
‘Superspreading’ events propel coronavirus pandemic - js2
https://www.washingtonpost.com/health/2020/07/18/coronavirus-superspreading-events-drive-pandemic/
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js2
> Some people will not transmit the virus to anyone, contact tracing has
> shown, while others appear to spread the virus with great efficiency.
> Overall, researchers have estimated in recent studies that some 10 to 20
> percent of the infected may be responsible for 80 percent of all cases.

> In a detailed analysis of outbreaks in Hong Kong[1], for example,
> researchers found three distinct groups of incidents. The superspreading
> individuals, representing 20 percent of the total, were responsible for 80
> percent of transmissions. A second group, involving about 10 percent of
> cases, transmitted the virus to one or two others. The final group, 70
> percent, did not infect anyone else at all.

> In Israel, investigators looking at 212 cases[2] concluded that they could
> be linked back to 1 to 10 percent of people. And in an outbreak in a South
> Korea office tower[3], investigators found that about 45 percent of 216
> workers got the virus from a single person. In the United States, an
> analysis from five counties in Georgia[4] found that superspreading appeared
> to be “widespread across space and time,” and that 2 percent of the infected
> seeded 20 percent of the cases.

...

> Most of these events took place in coronavirus hot spots of which most
> people are now aware: buildings where people live in close quarters, such as
> nursing homes, prisons, worker dormitories and cruise ships. There have been
> a fair number of clusters at meat-processing and frozen food factories, as
> well as at a curling event in Edmonton, Canada, leading some to speculate
> that temperatures could be a factor.

...

> The rest of the known superspreading events were set in a hodgepodge of
> social venues where people gather in crowds: concerts, sports games,
> weddings, funerals, churches, political rallies, restaurants, shopping
> centers. And nearly all took place indoors, or in venues with indoor-outdoor
> spaces.

...

> While it’s often impossible to identify the person who triggered an
> outbreak, there have been some commonalities among those who have been
> pinpointed as the likely source in studies. They tend to be young.
> Asymptomatic. Social. Scientists suspect these “super-emitters” may have
> much higher levels of the virus in their bodies than others, or may release
> them by talking, shouting or singing in a different way from most people.
> Research based on the flu, which involved college students blowing into a
> tube, showed that a small percentage tended to emit smaller particles known
> as aerosols more than others. These particles tend to hang or float, and
> move with the flow of air — and therefore can go much farther and last
> longer than larger droplets.

1\.
[https://www.researchsquare.com/article/rs-29548/v1](https://www.researchsquare.com/article/rs-29548/v1)

2\.
[https://www.medrxiv.org/content/10.1101/2020.05.21.20104521v...](https://www.medrxiv.org/content/10.1101/2020.05.21.20104521v1)

3\.
[https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article](https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article)

4\.
[https://www.medrxiv.org/content/10.1101/2020.06.20.20130476v...](https://www.medrxiv.org/content/10.1101/2020.06.20.20130476v2)

