# 2501
UPDATED: A hat tip to SophiaZoe posting on the Flu Wiki. She points out that the .53% CFR, and the stated 640,000 deaths, only works if the percentage is based on the entire population (128 Million) of Japan, not on those infected.
Assuming a 25% attack rate, this would make the CFR slightly over 2%. This should teach me not to blog until I've fully consumed my first quart of coffee.
Nice catch, SZ. Thanks.
Earlier this year Japan released their pandemic planning assumptions, and they were basically the same as we use here in the United States.
In Japan's Pandemic Assumptions Released, I blogged:
The pandemic scenario envisioned by the Japanese government closely matches the United States, and some European nation's, pandemic assumptions.
Roughly 40% absenteeism, an attack rate of 25%, and a CFR (case fatality ratio) of 2%.
Of course U.S. officials are quick to point out that while this would be a severe scenario, comparable to the 1918 Spanish Flu, it isn't the worst-case scenario.
Yesterday, the Mainichi Daily News carried a story telling us that the focus of pandemic planning is changing in Japan, and that once again provided their pandemic assumptions.
This time, however, the expected fatality rate (CFR) is given as 0.53%, a 75% reduction over the earlier rate. (See Update above) Why this change was made isn't stated in the article.
Pandemic assumptions are nothing more than guesses, of course. Educated guesses - but guesses none-the-less. No one knows what the next pandemic will serve up. We could see another repeat of the mild 1968 pandemic, or a return of the horrors of 1918.
The assumptions used by the United States federal government are based on the known severity of the 1918 pandemic in the U.S. In various countries around the world, and for reasons not well understood, the CFR varied from well under 1% to 10% or higher.
The really big change in the Japanese plan is a move away from strict containment (which was unlikely to work, anyway), to limiting the spread of the disease and limiting it's social and economic impact.
Details of of exactly how they plan to do that, presumably, will be released once the plan is approved.
This story from the Mainichi Daily News.
New flu outbreak plan emphasizes limiting spread
(Mainichi Japan) November 29, 2008
A new influenza outbreak emergency plan has been drafted by the government, with emphasis moved away from strict containment and prevention of a new type of flu virus to limiting the spread and damage of any epidemic.
The new plan, announced on Friday, has two main goals: controlling the spread of infection and minimizing its effects on health; and preventing social and economic breakdown. It will be formally approved early next year following a public feedback session.
In addition, proposed measures submitted by specialist Ministry of Health, Labor and Welfare committees and other groups have been upgraded to 10 guidelines, which "provide us with a general outline for any counter-epidemic policy," says the Cabinet Office.
The new plan covers nine topics, including vaccination, medical care and preservation of social and economic functions. While recommending that all those infected during the early stages of an epidemic are hospitalized, the new policy for medical treatment requires that patients not in immediate danger be discharged later to provide beds for the seriously ill during the main infection phase. There are also policies for pre-pandemic vaccination, depending on vaccine efficacy, and a recommendation to increase stockpiles of the drug Tamiflu to treat 45 percent of the population.
The assumed scale of the epidemic is an infection rate of 25 percent, with a 0.53 mortality rate leading to a maximum of 640,000 deaths. By week 5 of the pandemic, around 101,000 people are predicted to be hospitalized daily, and 40 percent absent from work.
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