I love the smell of hysteria in the morning.

In case no one's noticed this yet, we're still getting quite a bit of our food supply through Mexico. If we cut that off via the Kaiser-esque* mentality of "closing the frontier", then it poses a wee bit of a quandary: What are people supposed to eat?

*visions come to mind of a pudgy, impish little McCain figure clumping around in hip-boot-sized jackboots while wearing a spiked helmet, with an Iron Cross hung 'round his neck, but it's dragging behind him on the ground because it's the size of a 1948 Buick....

I don't think it's quite fair to paint this is a mostly knee-jerk Republican close-the-borders issue.

And, Steve, you spend a good amount of time talking about how important it is that this disease has a long incubation period. Well, so what? You can strip that out of the article, because closing a border means nobody gets across.

I'm now in a country that has cancelled all air traffic to or from Mexico. I thought it was stupid on it's face. You can not stop a virus from spreading.But then I thought, we don't need to stop it from spreading. We just need to BUY TIME to study the virus and come up with some effective countermeasures so by the time it does arrive, we are a little bit better prepared.

As someone wrote a while ago, man has but three enemies: famine, fever, and war; of these, fever is the worst. We will be hit with a devastating fever that will kill a good chunk of our population in a short time. We can't know when it will happen, but it is inevitable.

I know that our ability to be manipulated into fear has been exhausted by Bush and the local news. I know that Democrats now take pride in not being the party of Chicken Little. But there are some things that ARE quite serious, and I think it is petty to mock people for being scared of something that could be real.

If you want to make fun of Republicans for something, go back and look at their votes on public health.

Oops. Hilzoy, not Steve. Can't keep up. Just glad I didn't say Kevin.

Time to be a devil's advocate. With all due respect, Hilzoy, I don't think your arguments are that strong.

1) Closing the barn door, er, border, after the horse has gone.

Sure, swine flu has already made it across the border. But every confirmed case so far has been infected by someone who brought the flu from Mexico - and the flu will still be harder to contain if there is a steady supply of people bringing the virus in from Mexico.

Since you're getting into the math, you're talking about the iterations of a term a*x^n as n goes from 0 to infinity. The key thing is to alter circumstances so that xeverybody.

2) The border closing has to be completely effective to do any good at all.

Not really - if we were trying to keep swine flu out altogether (too late!) that argument would be valid. But what we'd be trying to do at this point is minimize the number of starting points for those geometric series that will take off if x>1. What public health officials are tryiing to do now, as far as I can tell, is contain the disease before there are too many clusters of infected people here to keep track of. Drastically reducing new cases coming in from Mexico makes that game easier to play. (Once we already have too many clusters of infected people to keep track of, then closing the border will make no sense.)

3) What about trade?

Let shipments of goods continue - that can be done consistently with limiting the number of people crossing the border to a relative handful, and that's the key.

Counterarguments are welcomed.

Looks like I chopped off my last paragraph under point (1) above: that's what I get for trying to post from a mini-laptop. Let me try again:

Since you're getting into the math, you're talking about the iterations of a term a*x^n as n goes from 0 to infinity. The key thing is to alter circumstances so that x

What closing the border does is keep the a term constant, or at least minimizes its increase. And in the early stages of an epidemic, where public health officials aren't intervening population-wide, but are trying to contain discrete clusters of infection, that makes a big difference. Leaving the border open turns a into a rapidly increasing variable, allowing a steady stream of new disease vectors into the country, and hastening the point at which disease interventions have to be population-wide rather than aimed at containing isolated sites of infection.

If this turns out to be a true pandemic, there will be waves of the disease, with the second wave more infectious and virulent than the first. This is what happened in 1918, when the first and mildest wave subsided and was followed months later by the deadly second wave for which the epidemic is best known in the U.S. (There was also a third wave elsewhere.)

My question is: if you have a disease-free locale without any land borders, say, Hawaii, what do you do when the second wave begins on the mainland U.S. or somewhere else in the world?

I wonder if allowing only outgoing flights and incoming cargo ships, from which the crew could not disembark, could stall the spread of the disease long enough to vaccinate the state's population. During this time workers in the travel and tourism industry would have to receive unemployment benefits and food stamps.

This is assuming the CDC decides to begin making a vaccine for the Swine Flu and it's ready by September and the second wave begins no earlier than July.

Why don't we close the border with Texas?

If the pandemic gets much worse then anyone who opposes travel restrictions should be prepared to be punished quite heavily at the polls. Of course the Republicans will use it as an issue, that's what they do. We should not fail to consider the economic hit of getting them back in power as well as any of the ones offered by Hilzoy.

At this point we can't know how bad the pandemic is going to be. I'm guessing not that bad. But to be sure, I am also preparing to be wrong, which is something Hilzoy should also be preparing for. If we Dems are seen as the ones who kept America's southern border open as a wave of disease flooded in despite public opinion, then we can expect to be punished for it. Since the Democratic party has most of the Latino vote, this can easily be portrayed as a political move on our part to keep them happy (and IMO it would be largely accurate).

This is not to say that the science/logic Hilzoy espouses is wrong, but the political optics are also quite important and should not be forgotten. We are the Mexican-friendly party, and since this is coming from there we are going to take a hit if things go badly.

I'm not prepared to let the Republicans crawl back from the dead just to avoid pissing off some Latinos and/or losing some trade with Mexico, but that's just my opinion. If that opinion is shared widely enough and we refuse to listen to the public sentiment, then our party will suffer the consequences and we will see what the costs of that will be. Pragmatism is often unpopular in the blogs, but most people will admit that purity on certain issues is a sure fire ticket to losing ground on a host of issues. The first job of political power is to avoid losing it, and IMHO this is about to be a huge loser of an issue if we don't watch out.

Amen, Jeff, @ 6:52 a.m...

uh. good grief. i contributed to massa; never would i have expected that kind of idiocy from him.

In case nobody has noticed:

a) it's currently taking about a week to to get samples analyzed by the CDC in order figure out if the strain of flu a person has is actually the swine flu

b) virtually all samples are turning out to me some other strain of flu, not swine flu

c) the swine flu is proving to be no more virulent than the regular flu....most people are recovering just fine.

So will somebody please tell the media to stop panicking!!!

In case they didn't realize it, over 50,000 people die each year from the regular flu. The fact that a few people have died from the swine flu is statistically insignficant.

AHHHHHHH We're all going to die!!!!!!!!!!! Quick someone get me some Duct tape and Visquine....

@ Linda @ 7:33
Evidently Massa was born in SC and is a former Republican. Almost surprising if he didn't react this way..

Ken, Oh My Gawdess, born in SC and was a Republican, Horror of Horrors - He was born in SC because his father was a career Navy officer - Did you check to see why he switched from the RepuGs? He was against the Iraq War - He was an aide to Wesley Clark and supported him.

You and Steve may disagree with this former Navy Officer, an Academy Grad, who served honorably for 24 years, but, get your facts straight without trying to cast aspersions due to his place of birth and early party affiliations. Rep Massa is doing a great deal to support returning vets.

Members of the Minutemen should be dispatched to the borders with extremely tiny shotguns to stop the wetback viruses from invading our land.

Given the non-existent mortality of this swine flu (the only reported American fatality was a mexican child who happened to die in Texas....

Should we block out visitors who bring teh less dangerous variety to us? As mentioned above, the second wave of flu, should taht model apply could conceivably wash over a populace already immune because of teh less dangerous wave.

Do we climb inside the sterile bubble only to get hit b y somethign far worse once we peek outside?

Fabulous epidemiology summary, Hilzoy. Your articles complement Steve's daily briefings so well, it makes the column a constant joy to read.

"Why don't we close the border with Texas?"

I was thinking that myself, but didn't want to throw ScottW into a tizzy by suggesting it.

Calls to close the border are as sane as refusing to go to the store, or let anyone in your family leave the house for any reason for two weeks: no food, no medicine, no income. Now apply that philosophy to everyone on your block or in your city.

The real problem is students coming back from vacations. Each student mixes with hundreds of other kids each day at school, much more than most people.

Bloggers are probably the safest potential carriers of this bug.

so we're closing the border with canada too, right?

i mean, if the canadians are letting mexicans in, then the canadians are just as dangerous.

if we're going to close the border with mexico, then we have to also forbid travel into the united states from central america -- all of south america really unless they have banned travel from mexico ...

i think it hilarious that there are so many arguments in the thread for why closing the border is a good idea.

pandemics don't have nearly the opportunity to kill that they once had. we have better medicine, we have better screening, we have better hygiene.

caution and care are warranted. but attempting to close a very porous border is ridiculous. people are going to cross it, but without benefit of health screening.

once closed, how long till it's reopened? you don't think there wouldn't then be a political battle about when it's "safe" to reopen?

put more people on inspection at the borders, take the temperature of people as they come across, turning back anyone with even a fraction over normal, but closing the border is ridiculous, to partially close it (allow movement of goods) is the height of stupidity.

low-tech cyclist probably made this point better than I will, but anyway...

Unfortunately, the flu is infectious for about a day before people develop symptoms. That means that any attempt to screen people at the border will not work. (So much for those heat sensors.)

"will not work"? That seems awfully strong. I agree that your reasoning shows that it will not be an infallible defense, but neither will hand-washing. Hand-washing wont save you if someone sneezes in your face. So should we forget about hand-washing? Seems like that would be a bad idea to me.

I'm not saying that I support border closure. However, the heat sensors sound fairly sensible to me. While I normally greatly appreciate hilzoy's thinking, I didnt find the case against heat sensors here to be at all persuasive.

I live in Tucson. I know a lot of people who live in Nogales, AZ, our equivalent to San Diego/Tijuana. A number of people living in Nogales, AZ, or Nogales, Sonora, live on one side of the border and work on the other side, therefore crossing the border at least twice each working day. This is typical of border towns.

Are we therefore supposed to inform all these people that they cannot work for some indefinite period of time, or that they must seek other jobs in shaky economies on both sides of the border?

TG in LA: A person can be infectious with the swine flu for at least a day before actively displaying symptoms, including fever, which is what I assume heat sensors would be used to detect. So a person could have already crossed the border and infected their 1 to 4.6 or whatever people before the heat sensor would be effective. Moreover, people can run fevers for a variety of diseases, too much sun exposure, etc., so you could end up keeping a person from crossing who was not infectious in any serious way. Not to mention that there would be a cost to bringing in heat sensors to places which don't already have them. Seems to me like a lot of trouble for a small return.

Others have already pointed out that so far, the swine flu is of low mortality and even morbidity, with most people being sick for a few days as they are with most cases of flu. I will also remind people that there was a lot of concern back in 1976 over that year's outbreak of swine flu, which turned out to be a non-issue. Let's keep this in perspective.