The Light at the End of Lockdown — what the final Numbers and Figures from Wuhan tell us

Wuhan’s lockdown had 3 phases, transmission going down with each set of stronger measures, now published in a top medical journal. Which phase is your city in?

A top medical journal just published the numbers showing how transmission of Covid-19 dropped with each stage of societal response in the first phase of the brewing epidemic. When it came out, I scrolled straight to the picture with the R(t), figure 4: the effective reproduction number of the virus (the higher the number, the more people get newly infected for each already-infected person).

The curves made my data-obsessed heart leap for joy. In the beginning, when they did nothing, an estimated one person infected three more. By the end of the first phase of city lockdown, with home quarantine and suspension of traffic, that dropped to about 1–2 (one person infecting one or two other people). By the time of the last two phases of lockdown (centralized quarantine, surveying everyone for symptoms), the transmission rate went down to nearly zero. That meant, for most people infected in this final stage, the buck (virus) stopped there, and did not get passed on.

Then, I scrolled back to the paper and read it properly (i.e. from beginning to end). (Please don’t judge — it’s not quite like reading Agatha Christie and jumping to the last chapter to found out who really did it.) This time, I scrutinized Figure 1: exactly what happened at each stage of the lockdown (clue: it wasn’t just one type of lockdown).

That’s when I realized, the first phase of “lockdown” sounded like what most countries in the West are doing now (closing essential services apart from drugstores and supermarkets and home quarantine if people do not need hospitalization). Back then in Wuhan, where the true danger of the pandemic at the time was not yet known, that did not work as well as it hoped (every person infected is spreading Covid-19 to one or two other persons, is still, well a 1:1–2 ratio of spread). The curve flattened, but it did not crush. Even ignoring the frightening spike in cases when they started counting patients thought to have Covid-19 but no laboratory confirmation, the curve was leveling out, not going down.

That was when the second phase was implemented. At this stage, everyone had to stay home, and home quarantine was changed to centralized quarantine.

In the last phase, which, in hindsight, looks like the happy ending of a home-run (which, to its residents, must have looked like “how can this get any worse”), they distributed all essential items (food, etc) centrally, and the “monitoring for symptoms” were done by centralized teams (not self-monitoring, as in the earlier stages).

Throughout this whole period, public and private transportation were severely curtailed, and wearing masks in public was compulsory, as it is now in Austria and the Czech republic.

Just before lockdown ended this week, when new cases were close to zero, residents were still being checked via a phone app with a “green” code (for no symptoms) before being allowed to leave the neighborhood. Contrast lockdown in North America: there is nothing to stop us from jogging, although this study modeling breath-flow suggests that the radius around people going fast needs to be greater than those walking or standing still.

There is an even more remarkable story emerging from across the world: this Italian town eradicated the disease in 14 days, by testing all 3000 residents regardless of symptoms. Understandably, that is not easy for larger communities. Having said that, while South Korea has been using extensive testing and tracing to flatten the curve, it has not quite “crushed” it.

While friends compare notes over social media as to who has the “worse” lockdown and commiserate, I looked at Figure 1 and did not feel the leap of excitement of Figure 4, because I realized, where I live, we are only in phase 1 of lockdown.

I do have hope though: because we are wiser now as to how deadly and infectious this is, maybe we can achieve the same outcome.