Japan: 40% of workers might have to stay home in flu pandemic (updated)

Via The Daily Yomiuri: 40% of workers might have to stay home in flu pandemic. Excerpt:

The Health, Labor and Welfare Ministry estimates that up to about 40 percent of the workforce would be forced to stay home in the event of an influenza pandemic.

The ministry estimates that the pandemic also could cause social and economic problems, such as medicine shortages and power outages.

For the first time, the ministry released estimates of problems that could be caused by a flu pandemic, hoping companies and other organizations would draw up preparatory measures.

The ministry also released a revised outline of suggested actions for companies in case of an outbreak.

Estimates were based on the human suffering figures in government's pandemic relief action plan--revised in October. The plan estimates 25 percent of people would suffer from a new influenza pandemic, with a fatality rate of 2 percent.

Since Japan's population is currently around 127 million, that would imply 31 million cases of H5N1 and about 635,000 deaths. The estimates on attack rate and case fatality ratio are likely drawn by analogy with worldwide statistics for Spanish flu.

According to Wikipedia,

In Japan, 257,363 deaths were attributed to influenza by July 1919, giving an estimated 0.425% mortality rate, much lower than nearly all other Asian countries for which data are available. The Japanese government severely restricted maritime travel to and from the home islands when the pandemic struck.

Japan's flu statistics for 1919 raise some questions. If a quarter-million people died with such a low CFR, that suggests something like 50 million Japanese must have caught Spanish flu.

And since the population of Japan circa 1920 was about 56 million, either everyone caught the flu in Japan, or the CFR was a lot higher than 0.425%.

The impact of the 1918-19 pandemic on Asian countries doesn't seem to have been studied very closely, but if anyone can point me to some good sources, I'll be glad to post them.

Update: SophiaZoe has a thoughtful response to the Yomiuri story.