Jonathan Kamens 86 47Jul 16
I keep reading about how #COVID levels are going up all over the place, but if the wastewater data is to be believed, they are nearly as low as they have ever been in parts of Massachusetts served by Deer Island.
Levels in #Boston have been so low for so long that my wife and I are considering lowering our precaution levels. It sure would be nice to eat out in a (not-crowded) restaurant!
But what's got me worried is that I don't understand _why_ levels are so low.
Ref: https://www.mwra.com/biobot/biobotdata.htm
Show threadepwJul 16
@jik Yeah, I've been hearing about it going up, and expecting the MWRA graphs to start to rise. It's weird that they haven't. I've wondered whether it's actually truly low, or if the detection doesn't work as well on current variants, like I've heard has known known to happen for rapid antigen tests.
Show threadrednikkiJul 16
@epw @jik But if that were the case I would expect to hear that some people I know have gotten COVID. But I haven’t heard anyone locally mention a recent case in weeks and weeks.
Show threadSteve Gisselbrecht

@rednikki @epw @jik

Unfortunately, I do know at least one current local case.

I too have been thinking about possibly eating inside a restaurant (for the first time since March 2020!) but my understanding is that the reported counts are based on consensus between two probe regions, and one of them has a mutation in the latest variant.

Jul 16 at 10:09pmWeb
Show threadJonathan Kamens 86 47Jul 16
@stevegis_ssg @rednikki @epw >the reported counts are based on consensus between two probe regions
MWRA publishes separate data and graphs for its two sample regions. While the graph I posted does overlay the two on top of each other, you can also view them separately. It is not a "consensus" measurement.
Also, counts are low in both MWRA regions. And as I pointed out elsewhere in the thread, that's while they're spiking elsewhere.
Show threadJonathan Kamens 86 47Jul 16
@stevegis_ssg @rednikki @epw >one of them has a mutation in the latest variant
…which I would be more concerned about if we weren't seeing spiking in the Northeast overall, indicating.
I do not think "The region served by Deer Island has a dominant COVID variant different from the rest of the Northeast U.S. that isn't being picked up by the wastewater surveillance" is a likely theory. Not impossible, certainly, just doesn't seem particularly likely to me.
Show threadepwJul 16
@jik @stevegis_ssg @rednikki That's a good point! I hadn't thought of it that way. Thanks for the insight! Still wish we had more of a mechanism. Greater Boston is so much denser than the rest of the northeast, which makes it hard for me to hope for something like herd immunity making up for the difference, but I don't know nearly enough to really evaluate.
Show threadSteve GisselbrechtJul 16

@jik @rednikki @epw

Sorry, I was being brief. My understanding is that each of those measurements is a consensus of a measurement made on two different regions of the viral genome. Either one can have a false positive (qPCR is a very sensitive method but brutally prone to false positives ASK ME HOW I KNOW), so when you see both then you believe that it's really there.

Agreed 100% though that it's encouraging to see signal elsewhere and not here. They *probably* use the same test.