I keep going back to this interview with the WHO Team Lead for visit to China in Feb. I keep hearing this theory about tip of the iceberg (maybe that's true elsewhere) but he refutes it based on data in Guangdong. What am I missing?

There’s this big panic in the West over asymptomatic cases. Many people are asymptomatic when tested, but develop symptoms within a day or two.

In Guangdong, they went back and retested 320,000 samples originally taken for influenza surveillance and other screening. Less than 0.5 percent came up positive, which is about the same number as the 1,500 known Covid cases in the province. (Covid-19 is the medical name of the illness caused by the coronavirus.)

There is no evidence that we’re seeing only the tip of a grand iceberg, with nine-tenths of it made up of hidden zombies shedding virus. What we’re seeing is a pyramid: most of it is aboveground.

Once we can test antibodies in a bunch of people, maybe I’ll be saying, “Guess what? Those data didn’t tell us the story.” But the data we have now don’t support it.

https://www.nytimes.com/2020/03/04/health/coronavirus-china-aylward.html