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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."
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....
www.eFax.com are spammers
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.
More than mere navel gazing.
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.
"Provided by the management for your protection."
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:
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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:
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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.