A few days ago it was 21.2 percent. The new number is from the second round of tests, leaving me with the same question Nate Silver had: Is this new 25 percent figure the product of a bigger sample or is there reason to think that prevalence in NYC has increased by four points or so between the time of the first round of testing and this second round? If the latter, can we guesstimate how long it’ll be until they reach the 60 percent or so needed (we think) for herd immunity effects to be seen?

Maybe that doesn’t matter. A more humane way to think about the road to herd immunity is how many deaths, not how much time, it’ll take to get there. If the price of 20 percent of the city getting infected was 10,000 or so fatalities, we should expect 20,000 more, whether sooner or more gradually.

Regionally, the results suggest:

24.7% positive in New York City
15.1% positive in Westchester/Rockland
14.4% positive on Long Island
3.2% positive in the rest of the state

The governor said he’s going to conduct antibody surveys of 1,000 NYPD and FDNY personnel to determine the infection rate in those organizations. A similar survey will be done with 3,000 health care workers and 1,000 transit workers.

We should have comprehensive data from New York soon-ish, as Cuomo says he’s authorizing 5,000 independent pharmacies to conduct antibody testing going forward. Quickie math: If 24.7 percent of NYC has been infected and 12,287 city residents have died, that would mean an infection fatality rate a shade under 0.6 percent…

…if you accept the official death toll as definitive. We have a denominator problem in calculating the disease’s fatality rate since no one knows how many people have been infected. (Including many of those people. It may well be that a majority of all infections are asymptomatic.) Antibody tests will give us an inkling. But we have a numerator problem too. Just as many people have gotten infected and recovered without ever having had their illness confirmed as COVID because they were never tested, many have died without their deaths being confirmed as due to COVID because they were never tested either. How many of those are out there?

“Excess deaths” are the subject of two stories worth your time today, one from WaPo about the extent of the problem here in the U.S. and the other from the Financial Times about the extent globally. The calculation is simple: Take the number of people who died of all causes in a given city/state/country during the last week or month of this year and subtract the number of people who died in the same jurisdiction over the same period last year. The difference should give us a rough sense of how many people died directly *and indirectly* from the coronavirus epidemic. “Indirectly” would be someone who died at home from a cause unrelated to COVID because they were too afraid of getting infected — or dying in isolation — to go to the hospital. Case in point:

The family of Long Island resident Adrian Sokoloff say they believe he is one of the uncounted. The retired owner of a pet products company, he had just celebrated his 99th birthday when he started showing symptoms of covid-19 on March 19, his daughter Karen Sokoloff said. His family said his pulmonologist diagnosed him with covid-19 because of spiking fevers and coughing — and because two of his caregivers had come down with chills and lost their sense of taste, a telltale sign of the virus.

Sokoloff’s children had decided not to take him to a hospital out of fear that he would die there alone. They couldn’t get him tested for covid-19 at home.

Was Sokoloff a direct or indirect casualty of coronavirus? Other people may be dying as a direct cause of the disease but without doctors realizing it. For instance, not until the last 10 days or so have I seen it widely reported that some patients, many of them younger than you’d think, are dying of strokes due to the virus’s frightening ability to cause blood clots in some victims. How many people with coronavirus had fatal strokes in the first month of the epidemic that went unrecognized by doctors and EMTs at the time as a symptom of COVID-19?

Here’s what WaPo found when it looked at “excess deaths” in various U.S. hot spots through the month of March up until April 4:

In New York City and New Jersey, there were more “excess deaths” during that period than there were official coronavirus deaths. If we add the 3,757 excess deaths in NYC that went uncounted in the official COVID death toll to the current official COVID death toll, we’d end up with a true fatality rate of close to 0.8 percent, nearer to the one percent rate that experts feared at the beginning of the epidemic. Again, that comes with an asterisk because some of the excess deaths aren’t directly caused by infection. But an excess death is an excess death, a fatality which we suspect might not have resulted if not for the pandemic.

And it’s not just New York City, says the Financial Times:

NEW: a lot of data on reported Covid deaths is highly suspect, so we’ve been looking into excess mortality — how many more people than usual have been dying around the world in recent weeks?

Story by me, @ChrisGiles_ & @valentinaromei (free to read): https://t.co/EiE5Q3OSmR pic.twitter.com/AiTdBnBma9

— John Burn-Murdoch (@jburnmurdoch) April 26, 2020

In Lombardy, Italy’s beleaguered northern region, there were 4,348 official coronavirus deaths — among more than 13,000 excess deaths. Excess deaths also show how stark the difference is between Sweden, which famously has avoided lockdowns and school closings during its outbreak, and Denmark. Denmark’s population is a little more than half the size of Sweden’s but Sweden’s number of weekly excess deaths far outstrips that difference:

The number of deaths recorded in Sweden in the first three weeks of April are 2354, 2505 and 2310 respectively, which equates to 530, 755 and 558 excess deaths compared to the average between 2015 and 2019 for those same three weeks. All three weeks saw more deaths than previous highs recorded in the past five years.

The equivalent figures in Denmark are 1152, 1138 and 1061 deaths, translating into 96, 69 and 36 excess deaths.

The 14 countries that the Financial Times looked at registered 122,000 more deaths than “normal” over the past few weeks based on historical averages. That was 45,000 more deaths than are accounted for in the countries’ combined official COVID-19 death counts.

I’ll leave you with this from a microbiologist involved in Mt. Sinai’s antibody testing program. He’s skeptical of Cuomo’s number, believing that the true rate of infection among New York City residents is far lower than 25 percent.

I think this is too high. It is possible. But a 20% plus infection rate seems too high for NYC due to a number of reasons. I would think 6-8%, maybe 10% are closer to the truth. It would be nice to know more about the test, its sensitivity and specificity and the test population.

— Florian Krammer (@florian_krammer) April 23, 2020