Thanks for this excellent writeup of a very promising project.
A somewhat useful comparator would be to the proportion of people in Wuhan who were infected at the time that SARS-CoV 2 was detected. According to this report, the pathogen was identified on Jan 8, and by Jan 18, their estimate is that 2,500 – 6,100 of the 11 million people were infected (they don’t seem to report a number for Jan 8, though you might be able to work it out from their doubling time results). That is about 0.02% – 0.06%. So it sounds like you would need to scale this up by a factor of 20 or so to detect it as quickly as Wuhan detected their non-stealth corona virus.
Of course, SARS-CoV 2 wouldn’t have been found anywhere near as fast if it were a stealth pathogen, so this comparison only goes so far, but it is a start.
I do think this is a useful comparison, but if you want to be able to detect something before ~0.05% of the people in any region are infected you need to scale up by a lot more than a factor of 20 ;) The issue is that (a) you’ll get up 0.05% in some region far before you get to 0.05% globally and (b) the detection system samples only some sewersheds and so in the likely futures where pandemic does not start in a monitored sewershed the global incidence is higher than the incidence you can measure.
Personally, I’m skeptical that with current or near future technology and costs we will see sufficiently widespread monitoring to provide the initial identification of a non-stealth pathogen: BOTECing it, you need a truly huge system.
EDIT: rereading the post, the initial version wasn’t clear enough that this was an estimate of what it would cost to flag a pandemic before a specific fraction of people in the monitored sewersheds had been infected. Edited the post to bring this limitation up into the summary.
Thanks for this excellent writeup of a very promising project.
A somewhat useful comparator would be to the proportion of people in Wuhan who were infected at the time that SARS-CoV 2 was detected. According to this report, the pathogen was identified on Jan 8, and by Jan 18, their estimate is that 2,500 – 6,100 of the 11 million people were infected (they don’t seem to report a number for Jan 8, though you might be able to work it out from their doubling time results). That is about 0.02% – 0.06%. So it sounds like you would need to scale this up by a factor of 20 or so to detect it as quickly as Wuhan detected their non-stealth corona virus.
Of course, SARS-CoV 2 wouldn’t have been found anywhere near as fast if it were a stealth pathogen, so this comparison only goes so far, but it is a start.
I do think this is a useful comparison, but if you want to be able to detect something before ~0.05% of the people in any region are infected you need to scale up by a lot more than a factor of 20 ;) The issue is that (a) you’ll get up 0.05% in some region far before you get to 0.05% globally and (b) the detection system samples only some sewersheds and so in the likely futures where pandemic does not start in a monitored sewershed the global incidence is higher than the incidence you can measure.
Personally, I’m skeptical that with current or near future technology and costs we will see sufficiently widespread monitoring to provide the initial identification of a non-stealth pathogen: BOTECing it, you need a truly huge system.
EDIT: rereading the post, the initial version wasn’t clear enough that this was an estimate of what it would cost to flag a pandemic before a specific fraction of people in the monitored sewersheds had been infected. Edited the post to bring this limitation up into the summary.