How is it that a crowded mega-city like Tokyo, without a stay at home order and with a menacing outbreak, managed to avoid a catastrophe? The key might lie in its people’s awareness of public hygiene — and masks in particular.

Mask-wearing has become an anathema to many parts of the US (and some parts of Europe) — but it may be a good part of why Japan and several other Asian countries are faring so well comparatively.

When you look at the coronavirus mortality rate, it is substantially lower in several Asian countries than the US or many countries in Europe. Japan is a particularly striking example. Prime Minister Shinzo Abe ended the national state of emergency last week as Japan has by far the lowest coronavirus figures in the group of seven major economies. Even as Japan wobbled as it took a hit from a second wave of infections, it is still standing.

Japan has no legal way to enforce a lockdown, so it relied on its population to respect the quarantine — and while the crisis is far from over, it managed to stave off the infections to a relatively low number. There are currently under 20,000 confirmed cases in Japan, which for a country of over 126 million, is stunning. The fact that Japan managed to keep its infections so low despite its sprawling urban agglomerations is even more impressive.

In a recent press conference, Japan’s national expert panel addressed some questions about why the country seems to be faring so well — and they cite face masks as an important factor.

“There’s strong awareness of public hygiene, starting with the habit of washing our hands. And, due to historical experiences, there is widespread knowledge about preventing infections,” the panel explained.

“Another social factor is that Japanese people feel comfortable wearing masks on a daily basis. Many people are allergic to pollen, so they do this during the cedar pollen season from the beginning of the year until spring, as well as to protect against influenza.”

Face masks have been a major point of contention over the course of the pandemic. A part of that is owed to the initial guidance provided by organizations such as the WHO and CDC. In part due to fears of shortage, in part due to a hesitancy to issue guidance on incomplete evidence, early guidance on face masks was confusing and contradictory — this did not happen in Japan and several other Asian countries. Face masks were recommended from the start, and they were already widely accepted in these societies.

But even so, the panel explains, Japan only barely managed to escape a health disaster.

“Japan’s health care system was on the brink of collapse, and we just barely managed to avoid that, thanks to an all-Japan effort. Even though we didn’t go as far as a lockdown like those seen in the U.S. and Europe, there has been great social and economic sacrifice. It’s difficult to find a balance between preventing the spread of the disease and social and economic activity.”

In the end, it was the common-sense measures that made all the difference: physical distancing, wearing masks, and hand hygiene.

“Cluster surveillance has enabled us to ascertain what situations and places present a high risk. We have found out that wearing masks, hand hygiene, physical distancing and avoiding talking loudly are effective in preventing transmission.”

Something else that Japan did with great success was cluster tracing. The cluster-based approach to disease control was designed based on the recommendations of the WHO. Each infection cluster is traced to the original source and everyone in the cluster is isolated and treated as necessary. This way, you don’t test randomly and massively (which can also work), but you spend a lot more time tracing clusters. The approach is not perfect, but it works.

However, Japan is not out of the woods yet. In order to keep the situation under control, Japan plans to step up its cluster tracing, in addition to other measures such as antibody testing and physical distancing.

“A second wave is very possible, so we need to detect clusters faster than before. We also need to use the antigen testing we have developed, alongside PCR testing, to find cases before symptoms become serious,” the panel concludes.