No Worse than the Seasonal Flu?

In a brilliantly conceived article published in the Lancet, researchers describe the early spread of SARS COV-2 in Wuhan and Seattle. They estimate there were up to 23,000 undetected cases in Wuhan prior to their lockdown Jan 23. (reported confirmed 422). They believe the disease began in China as early as October. China’s official COVID total was around 80k for the whole epidemic.

They retested swabs done for flu and found a surprising number positive for COVID that were flu negative. Then they used flu prevalence to estimate cases of COVID.

A similar calculation was done in Seattle, w similar findings. They thought there were 15,000 cases in the Seattle area well before it was first identified in January 20, occurring between Dec 25 and Jan 15.

To clinicians this is not surprising. We started seeing cases of what sure looked like flu but were testing negative. So many people have that story of an illness that was like the flu but different. More trouble breathing primarily. They were sprinkled in w all the flu cases in that time frame. We just called it a flu like illness. The guidance was to screen for a China travel history first, then China and Washington State, then Europe, then NY and finally just for symptoms. Now we know what a lot of them had, COVID-19. There is absolutely no reason to think this was not happening in other places like NY and the rest of the country. Chinese nationals were unrestricted until much later (February 2) and US nationals traveling to and from China and Europe were never restricted. Knowing now that the COVID test can be positive well after infection it’s possible the identified cases were from weeks or months prior. I have patients and parents w positive antibody tests that were never officially positive at the time of their illness, most of them were ill during those early days, proving it was here too.

What this means is what many of us have been saying for a long time. It was everywhere, spreading rapidly before we knew it. It is stealth because it’s mild in most allowing it to go through large numbers without causing too much alarm. Then it starts getting to more vulnerable populations and begins harming and killing. We finally start looking for it but it’s way too late to stop. Further it can be completely invisible in asymptomatic cases. It also means the case fatality and hospitalization rates are lower than they seem. Bigger denominator to divide them against.

The good side of this is there is now evidence that there are many more, likely many millions of people who were undetected early cases adding to herd immunity. Their antibody test may be negative because it happened so long ago but their T Cells are there ready to do battle on future exposures.

It also means stopping this was never really possible. It was uncontainable before we knew it was even here. I think what we did was slow it enough to allow our health care system to handle the big wave in the Northeast w heroic efforts and help from the government and military. When the  first wave moved to the rest of the country similar heroic efforts by front liners and all hospital staff proved up to that challenge. It’s in retreat now.

Somehow thinking it’s containable presently is no longer logical. In retrospect it never was. We just didn’t know it.

Credit to Dr. Peter Januzzi