Sunday, August 21, 2005

Bird Flu Simulation Makes Headlines in Taiwan

The Taipei Times reported today:

Department officials informed a meeting of the National Security Council that a simulation by the US' Centers for Disease Control and Prevention predicted 5.3 million Taiwanese -- nearly one-quarter of the population -- would be infected by avian flu, of which 70,000 would be hospitalized and 14,000 would perish.

It wouldn't surprise me that things could be bad if bird flu arrived on our fair shores, but one thing I don't see in the article in the Taipei Times quoted above is any discussion of the odds of a serious and uncontainable outbreak. One could think of numerous diseases that would kill 14,000 if they arrived here (Marburg or Ebola, for example). Nor is this new news -- it was reported in almost identical form back in March of this year. But what are the odds, folks? And what assumptions underlined the simulation?

As far as I can see the data is based on the NIGMS study from late last year. Here's from the original NIGMS announcement:

The flu project is part of a national effort, called the Models of Infectious Disease Agent Study (MIDAS), to develop computational models of the interactions between infectious agents and their hosts, disease spread, prediction systems and response strategies. The participating research teams are led by scientists at Johns Hopkins Bloomberg School of Public Health in Baltimore, Md.; Los Alamos National Laboratory in Los Alamos, N.M.; Emory University in Atlanta, Ga.; and Research Triangle Institute International in Research Triangle Park, N.C.
To simulate the spread of a possible avian flu outbreak that would become infectious between humans, the researchers are developing models of a hypothetical Southeast Asian community of about 500,000 people living in neighboring small towns. The computer simulations will incorporate data on population density and age structure, distribution of schools, locations of hospitals and clinics, travel and the infectiousness of the virus.'s the "neighboring small towns" part that throws me. It sounds like they are creating an idealized model and then projecting it onto Taiwan by simple calculation of population figures. In other words, the simulation isn't about Taiwan at all. I checked a couple of bird flu blogs, and also this bird flu blog, and this website on Avian Flu, but found nothing except the interesting fact of Kalmykia, a country I had no idea existed, and which according to Wiki is the only Buddhist country in Europe, except perhaps for Monaco, where the celebs also all live in the Eternal Now. Futurepundit has a huge collection of related articles that are very scary.

Foodconsumer has a report on the simulation, which is not based on data for Taiwan but for Thailand, a far less developed country.

To enhance reliability, both models were based on detailed data for Thailand, such as population densities, household sizes, age distribution, and distances traveled to work. The models also included information about the flu virus, such as the possible contagiousness of an infected person. Ferguson and Longini noted that actual contagiousness would not be known before an outbreak.

Pharmalive also hosts a story on it:

The model described in Science simulated 500,000 people living in rural Southeast Asia and relied on information about how those individuals move within their communities. Containment strategies included giving antiviral medication to people in the same social networks, vaccinating before an outbreak with a vaccine that is not well matched to the strain that emerges, quarantining the houses or neighborhoods of infected people, and combinations of these approaches.

Giving a low-efficacy vaccine to just half the population before the start of a pandemic would greatly enhance the success of other containment strategies, according to the model. Longini reported that a combination of targeted antiviral treatment and quarantine introduced two weeks after the first case had the potential to successfully contain disease spread, resulting in less than one case per 1,000 people.

Pharmalive even offers some cool pics like this one of the effect of an uncontrolled outbreak:

At the moment, AFAIK, the real story is that the simulation ain't too applicable to Taiwan because the data are about another kind of country and another kind of economy.

UPDATE: Mike Davis' terrifying commentary at MOJO on avian flu should not be missed.

"People just don't get it," Dr. Michael Osterholm, the outspoken director of the Center for Infectious Disease Research and Policy at the University of Minnesota recently complained. "If we were to begin a Manhattan Project-type response tonight to expand vaccine and drug production, we wouldn't have a measurable impact on the availability of these critical products to sufficiently address a worldwide pandemic for at least several years."

"Several years" is a luxury that Washington has already squandered. The best guess, as the geese head west and south, is that we have almost run out of time. As Shigeru Omi, the Western Pacific director of WHO, told a UN meeting in Kuala Lumpur in early July: "We're at the tipping point."

...yet another problem that could have been helped by the $300 billion wasted in Iraq.


Naruwan said...

Bird flu is especially scary when you consider that the bird flu of 1918 only killed a small percentage of those infected. The emerging strain may not be so merciful.

The UK gov't is working on the assumption that there will be a pandemic sooner or later. It all depends on the scale. The virus could mutate to a fairly harmless form, or it might go completely the other way.

Taiwan has been making plans but quietly. An emergency physician at a large hospital in Taichung told me that the gov't has been buying up anti-virals for some time now but wants to keep it low key to avoid mass panic.

Interesting you mentiuon Kalmykia - I first heard about Kalmykia through chess because the president of the world chess federation is also the president of Kalmykia. He is the sole reason that the chess world is so messed up right now. He ain't so hot when it comes to running his country either. Many Kalmyks live in extreme poverty while he spends millions on his chess obsession.

rmdazwdv said...

"During the Second World War, Stalin, suspicious of their loyalty because of their dissatisfaction with economic conditions, deported the whole Kalmyk nation without notice to Siberia in cattle trucks in midwinter. Half of their number perished during the journey and in the following years of exile, an ethnic cleansing unknown to the outside world to this day."

wayne said...

Of course you don't see an objective account in the pan-green Taipei Times about how an avian flu epeidemic would affect Taiwan. The TSU is trying to use the possibility of an avian flu epidemic to put the kibbosh on (of all things) the three small links. Of course, if another epidemic from China hits Taiwan, odds are much more likely that it'd be transmitted by some Taishang hopping back and forth from his factory and second wife in Zhejiang to his luxury pad in Taibei rather than some Fujianese fisherman giving to some Jinmen fisherman who in turn spreads to Taiwan.

(They only briefly mention in this article, but I swear I saw some TSU nut going on more about preventing avian flu through stopping the three small links in another article.)