Superspreaders data from India

Source: Marginal Revolution.

Tyler Cowen shares Covid findings from “the largest contact tracing study…conducted in the world for any disease.”

A datum that surprised me was this: “The researchers found that 71% of infected individuals did not infect any of their contacts, while a mere 8% of infected individuals accounted for 60% of new infections.”

To read the news and hear people talk about Covid-19, you’d think that nearly every infected person spreads the virus. In the study, only about a third did.

3 thoughts on “Superspreaders data from India

  1. The key measure is the average number of people that each infected person infects. That is R0 in epidemiological calculations. If it is a greater than one, the cases multiply rapidly. If it is less than one the pandemic peters out. So far, the R0 for the current coronavirus seems to be greater than one by a substantial amount and significantly higher than R0 for the seasonal flu.

    I notice that one of the key findings from this big study was that children are very efficient spreaders. That is evidence that bears on our separate discussion about schools.

    Like

    1. RE: “the R0 for the current coronavirus seems to be greater than one by a substantial amount and significantly higher than R0 for the seasonal flu.”

      Is that a fact?

      I googled this very question the other day. R0 estimates vary by virus, and even across studies of the same virus.

      I found R0 estimates for various strains of influenza ranging from 1.4 to 2.0. For the Covid-19 value, the most common estimate is the range 2.0 to 2.27, but there are studies that peg Covid R0 as high as 5.7. For comparison, measles has a generally accepted R0 of 15.0.

      I think it’s fair to say, as Dr. Fauci and many others have said, that Covid-19’s R0 is roughly comparable to that of a severe seasonal influenza.

      Like

  2. I had seen this same report on other websites. It is an interesting study.

    What is not taken into account is the differences in environments between India and other countries. Also potential genetic differences between folks in India and other parts of the world. Sub-Saharan Africa seems to be faring much better than other parts of the world.

    I am not questioning anything here, just pointing out some things that appears to be ignored.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s