September 11, 2020

New York Update. I took an extended break in providing reports on COVID data, but with school starting will now pick this back up again, on a semi-regular basis.

We seem to be seeing a small increase in the Westchester numbers over the past several weeks. Looking at the dotted trend line in the chart below, over the past month we appear to have moved from an average of daily new cases in the low 30s to an average in the low 40s:

Over the same time period, the number of tests being administered to Westchester residents has fallen a bit:

Putting together a slight rise in cases with a flat to falling number of tests administered yields a small increase in the testing-positive percentage, and that’s what we see in this chart:

However, I should caution that I do mean SMALL. The testing-positive percentage for the county over the past week has climbed back to just over 1%, which is the first time that has happened since the week of July 3. We bottomed out around a month ago at .69% (.0069):

Just to put this in perspective, though, let’s take a look at the testing positive chart since March 12:

As you can see, the upward motion at the end of the chart is very slight, and as we’ve discussed before with only a small number of people testing positive in the county each day, a pocket of cases here or there can have out-sized influence. And anything below 5% testing positivity is the threshold that the WHO suggests is the time to ease restrictions — that’s the same threshold NYS is using for schools. So there’s certainly no reason yet for concern, and our numbers could fall back down again.

There was an interesting article recently in the Wall Street Journal entitled “Covid-19 Positivity Rate Might Not Mean What You Think It Does.” It makes the point that looking at the percentages across many states, the underlying data on testing is very inconsistent. For instance, some states report number of tests given, others report the number of people tested (that is, they are only counted once even if they are tested multiple times). Obviously, without any real standardization, it’s hard to use the percentages for comparative purposes between states, at least with any real accuracy.

The article quotes Jennifer Nuzzo, an associate professor at the Johns Hopkins Bloomberg School of Public Health, as follows:

It is not a measure of the percentage of the population that is infected or even a measure of the incidence of new cases. It’s a measure of whether we’re doing enough testing.

Prof. Nuzzo’s point, according to the article, is that a high percentage positive results tells you that other cases remain undiagnosed and more tests are warranted, whereas low percentages suggest that “enough tests have been administered to ensure most infections have been detected and contained, interrupting the chain of transmission.” She also noted that “[t]he direction of the numbers is more important than the absolute numbers. If they’re stable or declining, you feel confident. If they’re rising, even if they’re low, that tells you something.”

But if there’s a primary point the article makes, it is that widespread, vigorous testing is key.

Although the number of tests administered in Westchester has been dropping a bit, we do administer over 4000/day and overall NY is probably more consistent than other states in the number of tests it administers. So I feel relatively comfortable that if we see a trend over several weeks in the positivity number, there really is a trend there. But still, it may prove to be short-lived, and in any event as long as the percentage remains in the low single digits, the virus at least under control (although certainly not eliminated).

One other measure of how we’re doing is fatalities, and the news in Westchester on that front is quite good. Since the beginning of August to date, we’ve lost 6 residents. Don’t forget, back in the spring we were losing upwards of 30 or 40 people per day. The total number stands at 1584.

I know the big question on everyone’s mind these days is school. I wish I had some deep insight for everyone, but here’s all I’ve really got:

1. We likely should be doing random testing of kids to monitor possible spread. However, for reasons that may have to do with the number or cost of having the right number of tests available and the potential for overwhelming the labs (again, this is just speculation on my part), random testing is not part of the plan here in Pelham and or in most other public school districts in the state (NYC being a possible exception).
2. The fact that such testing is not happening leaves us blind as to spread until someone gets obviously sick or is tested for some other reason. Given that so many infected people, especially kids, are asymptomatic, there can be significant community spread before anyone knows it, as we saw in Westchester in early March.
3. The PUFSD plan on testing is reactive rather than investigatory and just covers what happens once a case in the schools is identified: “Students and/or staff members who were in close contact, as defined by the department of health, with an individual who tested positive will be required to quarantine for 14 days.” Further, “[t]he District will collaborate with the Department of Health to make testing site locations and resources available to parents, students and staff as needed.” And finally, “[t]he Department of Health recommends that any student or staff member who was exposed to an individual who tested positive for COVID-19 get tested five days following the exposure.” I assume this meant to give antibodies time to show up in a test, but what’s a bit odd to me is that this seems to assume that the known infection is essentially Patient Zero, which may well not be the case. I’d prefer to see pretty rigorous testing of anyone who was in contact with the infected person right away, because maybe we’d catch others who were asymptomatic and passed the virus along to the person who is known to have it, or others exposed at the same time.
4. The experience with state “reopenings” across the country this spring and early summer further shows that there is a lag between the activities where people congregate more freely and when an outbreak becomes obvious, and then a further lag before hospitals become crowded and more people die. In places where people were not exercising precautions, the clear lesson is that big outbreaks did occur, if not of the exponential nature of the NY outbreak back in March.
5. The experience in colleges recently is still an experiment that has yet to fully play out. We are seeing outbreaks among students that are being identified likely more quickly than we’ll see in our public schools because there IS more testing being done at colleges. This appears to have limited the outbreaks to some extent, and the fact that young people tend to not get as sick has also limited the impact thus far. What we don’t know is the extent to which those smaller outbreaks may lead to greater community spread — it’s likely just too early to know. I tend to think the numbers involved in those outbreaks thus far may be too small to tip the needle in most places, but we’ll see.
6. The experience in New York since April tells us that wearing masks, social distancing and other protective behaviors reduce the spread of the virus. Enough so that even when we engage in more risky behavior — as we all do on occasion — the fact that most people are exercising some restraint in most circumstances seems to keep the overall spread low.
7. As a result of all of the above, I’ll continue to watch two things: (1) the Westchester (and NYS) testing positive numbers to see if they continue to rise once schools get fully underway with some form of in-person instruction; and (2) what type of action is taken when any outbreaks are identified in the schools.
8. On that latter point, hopefully the fact that the schools are requiring masks, personal shields, social distancing, separate low-density cohorts, etc. may prevent significant spread from one or a few single individuals who become infected. There seem to be examples of other countries where in-person instruction has moved forward with success, when the baseline infection level in the community is low and the types of precautions we are implementing here are taken.
9. Contract tracing and moving those who came into contact with any infected individuals to virtual learning for a few weeks makes sense. With respect to contact tracing the District plan says “[e]ach school will monitor the number of staff and children who are sent home due to illness as well as daily attendance. If there is a suspected or confirmed case(s) of COVID-19 or an increased pattern of illness, the School Principal or their designee will immediately notify Ms. Julia Chung, Assistant Superintendent for Pupil Personnel Services who will in turn notify the Superintendent of Schools and the Westchester County Department of Health.” Then, the DOH is to act as the primary organization responsible for contact tracing. Contact tracing has not been very successful in the US thus far, but hopefully here in NY, where the infection level is low, it will be helpful.
10. But finally, we all have to acknowledge that we are dealing with a natural phenomenon here, and one we cannot fully control. The shape of the pandemic may twist and change a number of more times before we reach any semblance of life as it was pre-COVID. The 1918 flu pandemic roared back in the fall and did its worst damage (among young people in particular), and then largely was done by early the next year. We may find that the kinds of congregating we’ve been able to do this summer will have different, worse results when we try similar things in colder, drier weather, or when we inevitably do more things indoors. We may see enough spread in schools that we have to move to virtual learning. Or we may be able to move to full in-person learning by January. We just don’t have a full playbook for this thing, still, and since the US hasn’t managed to crush it like some other countries, we’re living with it for some time to come.

Still, I remain hopeful, because here in NY we’ve managed this pretty well for a number of months now. If we see the trends going the wrong way, we understand that we need to act aggressively again and get it back under control.