linnugripiblog

The Battle to Stop Bird Flu link
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The first: "The superspreader hypothesis isn't necessarily true," Smith says. This rule holds that in any population, the more social individuals - the hubs - are the principal conduits for spreading disease. Shatter the network by inoculating or removing these hubs, the theory goes, and you'll stand a better chance of knocking out the disease. But EpiSims has shown that we're all more popular than we might think. Even the most reclusive of us runs to Walgreens for toothpaste or drops by Boston Chicken for takeout. For a highly communicable disease like smallpox or influenza, these incidental interactions spread disease just as well as extended encounters. So chasing after the hubs can mean chasing after 80 percent of the population - a huge waste of time and energy. Better simply to inoculate the entire city.

A second revelation: With a lethal pathogen like smallpox, response time is all. As the delay stretches from 4 to 7 to 10 days before officials move into action, EpiSims found that the outbreak becomes increasingly lethal. It turns out that, in the ticking moments after an epidemic strikes, when health officials act is more important than what they actually do. Start with inoculation. Or quarantine. Or school closings. It doesn't matter. What does matter is reducing the time between first outbreak and first response.

tehti nüüd linnugripipandeemia simulatsioon:

EpiSims has begun assessing the threat of avian influenza. They're modeling the health care system down to the hospital bed, to see what happens if flu victims flood hospitals, fill the beds, and then spill back into their homes. They're taking into account slight behavior changes, so if people start wearing surgical masks, SARS-style, disease transmissions in the sim will fall off according to the masks' particulates-per-million filtration rate.

EpiCast reveals that, in contrast with flu epidemics of decades past, an outbreak today won't progress "like a wave across the country," spreading from town to town and state to state. Instead, no matter where it erupts - Seattle, Chicago, Miami - it will swiftly blanket the nation. "It starts in Chicago one day," Germann says, "and a couple of weeks later it's everywhere at once." Thank the airlines. Even though disease has piggybacked on air travel for decades, we generally had only isolated outbreaks of low-transmission viruses - like when SARS leapt from Hong Kong to Canada in 2003 but failed to spread beyond Toronto. In an epidemic of a highly communicable disease, the airlines' hub network would effectively seed every metropolitan area in the country within a month or two - and then reseed them, repeatedly.

EpiCast showed that local intervention measures can have some impact: Close the schools, enforce a quarantine, and the disease will slow down. That buys the federal government time to develop and mass-produce a vaccine. But Germann quickly adds a caveat: Acting locally may not be enough. In a worst-case outbreak, without a viable vaccine, "the disease will climb, and eventually go exponential. And once it's on the exponential curve, it's very difficult to contain." Cue Richard Preston.

In November, the Department of Health and Human Services released its pandemic influenza plan. The report offers a thorough and frank assessment of the havoc a full-fledged pandemic would wreak. The nation, the report says, "will be severely taxed, if not overwhelmed." Disease will break out repeatedly, for as long as a year. Hospitals will run out of beds and vaccines. Doctors and nurses will be overworked to the point of exhaustion. Mass fatalities will overwhelm mortuaries and morgues with bodies.

Rather than an all-out response focused on one particular region, a flu epidemic would force the government to ration its resources to serve the entire nation.