The U.S. is now down to 37 36 34 new cases per 100K population per day, down from 38 at the end of last week 37 when I checked it a couple of days ago 36 four days ago. Daily new hospitalizations have fallen below risen to just over fallen below 6000 per day. Deaths remain around 350 375 400 per day.
Data source for this and other graphs of new case counts: Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 8/9/2022, from https://github.com/nytimes/covid-19-data.” The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html
This may be the new normal for the U.S. Cases more-or-less stopped rising at the end of May, settling in around 33 new cases / 100K / day. The official U.S. new case count has been that, plus-or-minus, ever since.
But that’s not true internationally. For whatever reason, it appears to be Japan and Korea’s turn now. Korea had a huge spike in cases earlier this year (peaking at roughly double the highest-ever U.S. new case rate). Now both Korea and Japan are nearing the U.S. all-time daily new case rate.
Source: Our World in Data.
With any sort of COVID comparison, you have to question the extent to which international differences are attributable to differences in testing and test-seeking behavior, rather than differences in incidence of disease. I note that the case mortality rate (COVID-19 deaths as a fraction of all officially diagnosed individuals) sorts these countries in the reverse order. That is, those with a lot of people being diagnosed have few deaths per new diagnosis. Those with few being diagnosed have a lot of deaths per new diagnosis.
Source: Our World in Data.
I’m not sure what to make of that, but it suggests that differences in testing may explain at least some of these international differences.
Speaking of differences in testing, how about all those polio outbreaks we’ve been having?
Are they real, or are they just an artifact of better testing methods? Short answer, they’re real. And the U.S. outbreak is in an area with exceptionally low rates of polio vaccination among children. Who would have guessed?
One of the lasting impacts of COVID is the routine testing of wastewater for disease surveillance. Not only were states and cities doing it, colleges (including my daughter’s college) tested their sewage to monitor the level of COVID-19 circulating within the student population. It’s not that it had never been done before, but it certainly is done more often now than prior to the pandemic.
And so, I have to wonder whether this new tool is leading to new awareness of things that have been happening all along.
I mean, things could be worse. Things have been worse.
Source: US CDC, Morbidity and Morality Weekly Report, Annual Supplement, September 1965. Full write up in Post #1247
Source: Our World in Data.
Source: US CDC
But now that polio is back — in the New York City metropolitan area — another bit of U.S. public health history apparently gets tossed in the dust bin. I say apparently because I have to wonder whether these new polio outbreaks — in New York City and in London — aren’t really just an artifact of the implementation of wastewater monitoring?
In other words, have we always had some asymptomatic strains of polio circulating in the population? Strains not related to the polio vaccine itself. Or is this really, truly the first outbreak of polio in the U.S. for decades? Maybe we only know that there’s an outbreak because we have started routinely testing sewage for it.
Here’s an interesting factoid about the London polio outbreak from earlier this year:
Source: Nature.
Well, that’s interesting. Some novel strains of polio are in London wastewater, but nobody appears to have been sickened by them.
This year’s London polio outbreak is not even the first such “silent outbreak” of polio. That is, polio detected via wastewater testing, with no actual symptomatic cases of the disease. This source documents a 2013-2014 outbreak in Israel. That led to a campaign to increase vaccination rates for polio in the affected city.
For how many years have the British been testing London sewage for evidence of polio? For sure, I can infer that they’ve been doing that for several years, because they routinely find a few polio strains linked to vaccines every year (per this reference). I could not pin it down any more than that.
My conclusion is that DNA-based wastewater testing has been going on in London for some years. This latest London outbreak therefore isn’t some artifact of new testing methods, but is a genuinely new situation.
As it turns out, scientists began tracking polio in wastewater long before DNA (PCR) tests were invented. Per this source, in the 1940s, scientists would culture cells out of wastewater and (somehow) check for polio.
But what about New York? That’s a genuine outbreak as well, and not an artifact of new testing methods. Turns out, in New York, they actually diagnosed a patient with polio first. Only afterwards did they start waste water testing to see how widespread the disease may be (per New York State).
The upshot is that these two outbreaks both appear to be genuinely new outbreaks of polio that would have been detected by long-standing methods. In London, they have been tracking polio in the water for years. In New York, they detected polio the old-fashioned way, by diagnosing a person who was sick with it. There, wastewater tracking only began after a symptomatic case was diagnosed. We may know more about it now, due to DNA (PCR) testing of wastewater. But in both cases (London and New York), these appear to be genuine outbreaks of disease that were both detected by methods that had been in place for years.
Just FYI, full vaccination against polio confers 99% immunity, which lasts your lifetime. All U.S. states require children in public day-care facilities and public schools to be vaccinated against polio (per this source). Except sometimes (per this reference on states with exemptions from vaccination requirements.)
Oddly enough, the CDC can tell us that ~93% of infants have been fully vaccinated against polio by age 24 months. But nobody seems to be able to tell us what fraction of school-age children have received a polio vaccine. Even odder, the CDC knows that 92% of U.S. teenagers have received their Measles, Mumps, Rubella (MMR) vaccine (Table 32, this CDC source). But they don’t track the same statistic for polio vaccine(?!).
Given that (I think) every state requires MMR for public school children, and that same 93-ish-percent pops up, it’s a pretty good guess that only about 93% of U.S. teenagers are immunized against polio. And I’m further guessing that CDC doesn’t track that beyond infancy because if your parents didn’t get you vaccinated as in infant, they are unlikely to bother to do that later in your life.
And as the cherry on top of this particular desert, you can look up the infant immunization rates by county, for New York State. And, sure enough, the sites of the New York polio outbreak — Rockland County and Orange County, NY — have third-world-like rates of infant immunization for polio.
New York State, Polio Vaccination Rates by County.
Source: New York State
I didn’t know there were places like that in the U.S.
So now it all kind of makes sense. In that some people just have no common sense.
