Singapore Using Thermal Imaging to Check for SARS

Quixotic1 writes "Channel NewsAsia reports that Changi International Airport in Singapore, Asia's fourth-largest airport, is using walk-through thermal imaging devices to screen for people with SARS. 'If a person is feverish, reddish spots will apear all over his face [on the screen] and that person will then be set aside for further examination by the nurses.' A Reuters article says that the 'Infrared Fever Screening System' was originally developed for military purposes. They are being built by Singapore Technologies."

Comments

Infrared Fever Screening System?

[Blaine Hilton]

If this keeps up pretty soon we will just walk right to the plane and security will be automatic. It will detect if we have guns, knives, razor blades, bombs, burnable shoes, and not to mention if we have a cold, flu, bubonic plague, HIV. What's next? Automatically looking up our families' histories to find any "unpatriotic" tendencies? Are they going to analyze our DNA and see if we are "genetically inclined" to do something?

I don't think I'm paranoid, but this is starting to go overboard! On the other hand though we have SARS, which is pretty scare in itself. I understand why they are doing this, but what happens after SARS is nothing but history, if that happens at all? What reason will they give next time to check us for anything and everything?

Finally!

[Drakin]

A good, senseable use for airport security.

While a lot of folks will be up in arms over this, SARS is a large threat worldwide. Sure, this method will generate a lot of false positives, but it's probably less of an incovience than having to close down the airport and put a halt on all air travel, expecually in regions where SARS has a large presence.

And if I just had a cup of hot tea

[wowbagger]

And if I just had a cup of hot tea, or coffee, or am nervous, or if my traveling companion just said something horribly embarrassing, or....

What about non-SARS fevers?

[SolemnDragon]

would i need a doctor's note saying, for example, that i take a medication that causes similar conditions? Because there are some. ANd that, right there, would have to be verified, which runs RIGHT up against the whole healthcare privacy rights issue.

And i'm curious to know what happens to people after they get led away, and at what point this starts to make since, since after all they may have just infected an airport full of people who are still getting on their flights.

I agree that this is an issue; I don't want to die, and this is killing people. But I'm not sure that I feel good about the lack of limitations here; halfway down the slippery slope already seems like a good time to stop and ask which is more important, our right to privacy or our physical safety, and how much of each we really HAVE to give up in order for this to work...

Re:What about non-SARS fevers?

[The Cydonian]

If you have a fever, and are travelling from a SARS-affected country, you are automatically quarantined. In fact, the official policy in Singapore is that if you're sick, don't travel/report to work/do nothing. The body's immune system is weakened, and apparently, you stand a greater risk of getting infected with SARS.

latest info on sars

[Naomi Heller]

To view the latest info on sars check out the world health organization's specific site:

http://www.who.int/csr/alertresponse/en/ [ www.who.int ]

That is all! -Naomi

Spreading Disease

[Anonymous Coward]

I wish they would start doing this where I work. America is one of the countries in the world where going to work sick is considered a moral obligation. Many countries think spreading disease to your coworkers is bad for productivity.

abuse potential seems fairly low...

[Vellmont]

Assuming it's not just used as an excuse to stop anyone and harass them, this seems like it's fairly harmless. It's fairly simple to screen anyone stopped by the system for symptoms of SARS, which obviously is not really true when screening for terrorists.

I just wonder how effective it would be. It only takes a few people entering the country to start spreading the disease. If you've got one person with SARS coming into the country ever, and your system has a 90% chance of stopping that one person, then it's pretty effective. If however, you've got one person a day coming through with SARS, well after a week there's a 50% chance you've let an infected person through.

In other words the detection rate of your system has to be in line with the incoming rate of infected people, otherwise it's fairly useless.

At this point I'm sure there's nowhere near one person a day coming through any airport with SARS. But I also doubt the airport will only have one person ever come through.

No Pre-Flight Alcohol!

[4of12]

A friend of mine (Chinese ethnicity, as a matter of fact) had a condition where his face would break out into a red flush after he consumed alcohol.

A system like this could introduce some annoying false positives for SARS infected passengers.

OTOH, at least the extra inconvenience would not be as noticeable if one was sufficiently soused.

Smoking can fool the test

[Muhammar]

If the only basis is face surface temperature, taking substance causing periferal vasoconstriction will fool the test - the surface temperature will be lower.

The most common potent drug causing peripheral blood vessel constriction is nicotine. I have even seen thermal imaging pictures of extremities (hands, feet) before and after smoking a single cigarette. The "cooling effect" of nicotine is quite dramatic.

I'm tired of this...

[hitzroth]

So SARS is this year's "wonder disease". It's killed about 150 people world wide and has a 4% fatality rate. Those people are no less dead for having been killed by SARS, but SARS is getting press far out of proporiton with its true nastyness.

Would anyone care to guess how many people died of heart disease, cancer, influenza, HIV, etc in the past couple months? Hint: each carries *slightly* more than a 4% fatality rate.

Bring back the Plague! A particularly virulent and contagious version! I'm tired of these candy-assed diseases that can't even manage to end the lives of more people than die in car accidents in and around some major cities in a similar time frame.

Re:I'm tired of this...

[Wesley Everest]

Uh, there's no vaccination or cure for SARS yet, and it is highly contagious. Heart disease and cancer aren't contagious at all, and HIV is very difficult to give to someone. Influenza has vaccines. I'd say that sets SARS out ahead of the rest.

Sure, only 150 people have been killed so far, but the worry is that it will spread out-of-control worldwide, infecting tens or hundreds of millions of people.

Re:I'm tired of this...

[Elazro]

Look, I understand how this may look like hype - we've had a lot of disease scares recently (not to mention asteroid-scares, bio-terror scares, and so on.) But I think you have to give the epidemiologists some leeway, for many reasons:
1. The death rate may be much higher than 4%
2. The infection rate may be higher than any of the diseases you mentioned
3. The time period from onset to death seems quite short, and
4. This is the very beginning of a possible pandemic.

I'll get to the 4th point in a bit. First....

#3 is fairly clear. SARS seems to have a much quicker death rate than any of the diseases you mentioned except for influenza (which I don't think has recently had such a high mortality rate.)

To address #2, SARS seems to have a drastically higher transmission rate than AIDS. Cancer and heart disease don't spread per se. However influenza does spread quickly as well

To argue #1, note that 4% of the people who have been infected with SARS have died, true. However, many of those people are still infected and may die yet. To get the fatality rate, you have to look at how many people have _recovered_ vs. those who have died, not how many people have been _infected_. This could be well over 10%.
Combined with #2, notice that a disease with a 100% mortality rate which infects only 1% of the population is only half as dangerous as a disease which has only a 10% mortality rate which infects 20% of the population.

These last figures approximately mirror the 1918 flu epidemic, which killed 20-40 million people within a single year. Epidemiologists _are_ as scared as hell about another such influenza outbreak. That doesn't mean that SARS isn't a threat though.

So, now is time to address #4. Given that SARS seems to spread quite quickly and widely, may have a significant mortality rate, and kills fairly quickly, hopefully we agree that it could wreak havoc on the world. It may not be the worst epidemic, but it could still hurt us a lot. Now, we should take a look at epidemiology of the thing.
When a disease starts to spread, the infection rate grows exponentially for a while. Then, as the susceptible portion of the population dries up, new infections slow down and taper off. The shape of the infected population over time is a logistic, or S-curve:

{cute ASCII graphic deleted due to /. filter}

The important thing to note about this curve (invisible in my ASCII rendering, I'm sure) is that initially it behaves like an exponential curve. Thus, it rises gradually for a while, hits a knee, and then shoots upwards.

All the best health-care practices in the world won't help us once that knee is passed. It is impossible to quarrantine even 5% of the worlds population, so if the infection ever gets to that level, only the most severe of measures could contain it (shutting down all forms of travel, essentially). After 10% of the world's population is infected there is nothing we can do to contain it. Also note that at around that point, hospitals will be overwhelmed, and thus won't be able to alleviate the symptoms of SARS, and thus the mortality rate may rise (right now hospitals can devote all their resources to keeping SARS victims alive until they recover)

So keep in mind that while SARS seems kind of lame now, in terms of how many people it has killed, it exhibits some disturbing characteristics. If those characteristics turn out to be real, then SARS could rival (in the worst case scenario) the plague or the 1918 flu. Now that is jumping the gun a bit, but the facts remain that:
1. SARS is potentially very dangerous.
2. It spreads quickly.
3. It may gain a foothold before we know for sure how dangerous it is.

The reason public health officials are treating this "candy-ass" disease so seriously, is that it really does have the potential to become that serious. And by the time we know that, there isn't much we will be able to do about it.

-matt

P.s. Public health is hard. Declare SARS as the next plague and if your're right, people take precautions, SARS fizzles, and the people assume you overreacted and ignore your warnings next time. Don't warn the public, and risk a pandemic.

What about the incubation period?

[Kj0n]

It is possible that people are being infected with the SARS virus without having a fever yet. How will they get screened?

Fun fun fun!

[Alsee]

I can't wait to see the look on people's faces when I walk through the scanner with interesting patterns on my face in infrared paint!

Yes, there is in fact such a thing as infrared paint. Most Military vehicles are pained in a version of infrared paint that is "black" in infrared. It conseals them from infrared scanners and night vision goggles.

There is also a version of infrared paint that is "white" in the infrared. The Iraqi military had virtually no night vision or infrared capability so the "black" paint wasn't really any benefit. They therefore put an inverted V in "white" infrared paint on coalition vehicles to help avoid friendly fire.

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