How Infrared Images Could Be Part of Your Daily Life:
A fever is one indicator that someone may be exhibiting coronavirus symptoms, and the Centers for Disease Control and Prevention recommends temperature screenings in a variety of environments, including schools and businesses.
[...] When the pandemic took hold, I started seeing more and more companies like Amazon using this technology to help identify sick people in their warehouses. Thermal imaging cameras are beginning to appear in Subway restaurants. Carnival Cruise Lines, whose ships became hot spots for the virus’s spread, said all passengers and crew would be screened when it began sailing again.
The rapid adoption of infrared technology had me wondering how helpful it could be. Several systems are being rolled out, including camera-based ones and others that make people walk through thresholds like metal detectors. Could they actually help contain the spread of the virus while we wait for a vaccine?
A Harris Poll conducted in late March, just after the majority of the shelter measures went into place across the United States, found that 84 percent of respondents favored mandatory health screenings to enter public places.
[...] The growing use of the technology has raised privacy and other concerns.
Civil liberties experts have warned about data being collected on employees and used without their permission. Democratic and Republican lawmakers have proposed bills to help protect people’s information and privacy as data like temperature readings is collected, but the legislation has so far stalled in Congress.
“The road to hell is paved in good intentions, and the mass rollout of cameras should be seen for what it is: the mass rollout and further normalization of cameras,” said Ed Geraghty, a technologist at Privacy International, a British nongovernmental organization focused on privacy rights.
“We already see police repurposing streetlight cameras, put in place to monitor traffic and environmental data, in order to form criminal cases against those accused of vandalism — it would be naïve to believe the same will not be the case with these cameras,” he added.
All of this being said, could this technology work if used correctly? Yes. Is it better than nothing? It depends who you ask. But while we wait for a vaccine to be made, many see the benefits.
But will throwing infrared cameras up all over society make us safer from the virus? How might a grade school student react to seeing a classmate set off an infrared-based alarm walking into school? Will the time it takes to screen everyone trying to get into a building create problems for schools or offices? These are important questions that we will face in a post-quarantine world.
(Score: 0, Interesting) by Anonymous Coward on Sunday July 05 2020, @07:46PM (2 children)
The papers you linked to were both older studies than either paper I linked to and used smaller sample sizes (9 and 23 cases versus 90 and 100). The conclusions drawn by the papers you linked to were that viral load peaks a few days after symptoms develop. These are older studies that have since been contradicted by newer studies. All other things equal, there's a smaller margin of error when a larger sample size is used to estimate the mean of a distribution. Therefore, absent evidence to the contrary, the results from studies with larger sample sizes should be preferred. These studies suggest that viral load peaks around the time a patient first develops symptoms. Moreover, I'll link you to another article (https://publichealth.jmir.org/2020/2/e19464/ [jmir.org]) that discusses the frequency of asymptomatic transmission and cites a number of other studies about this.
Papers like the two you cited initially suggested that presymptomatic and asymptomatic transmission did not make a large contribution to the spread of the virus. Larger and more recent studies contradict this, which indicates that a large amount of the spread of the virus is due to people who don't have symptoms when they're spreading the virus. If they don't have symptoms, temperature checks won't detect that they're infected. It doesn't seem that the peak of infectiousness occurs four days after the onset of symptoms like earlier studies suggested. Regardless of whether the peak of infectiousness is at the start of symptoms or peaks in the couple of days prior to the onset of symptoms (as the first paper I linked to suggests), a large amount of transmission is driven by people who wouldn't be detected by temperature screenings.
(Score: 0) by Anonymous Coward on Sunday July 05 2020, @10:29PM (1 child)
No, now you're outright lying. Among the conclusions for my first linked paper...
And the second...
Did you miss where I bolded "within 5 days of symptom onset" from the second paper you linked?
You should have no problem quoting those sections then (spoiler: papers do not mention this) but it's really beside the point, your disputed claim was that the virus was more transmissible before symptom onset and you have presented zero evidence to support that. For your enjoyment, here's a discussion paper on asymptomatic transmission. [sciencedirect.com]
(Score: 1, Insightful) by Anonymous Coward on Monday July 06 2020, @12:40AM
To avoid this post from being needlessly confusing, I've quoted your text without additional formatting, but quotes from peer-reviewed journal papers are in bold.
Viral load is plotted in blue on figure 2 in your first paper [thelancet.com]. As I noted previously, there are large errors due to the small sample size. However, the peak in the mean viral load in saliva from the patients that were sampled actually occurred around day 4.
Here's what the first paper said about exactly that figure:
You also omitted text from the portion you quoted:
That caveat, which you did not include, is useful in interpreting the conclusions of the paper those authors referenced.
As for the second paper [nature.com] you quoted:
In fact, you quoted this exact text in your original comment. How, exactly, is it lying to reference the exact text you quoted in your original comment? It would be appropriate for you to reconsider what you said and clarify it.
Let's contrast these results with what's in the papers I cited.
From the first paper [nature.com]:
And from the conclusions of the second paper [jamanetwork.com]:
And then part of your final paragraph:
A few months ago, public health authorities downplayed the risk of asymptomatic and presymptomatic transmission, guidance that has now changed to reflect the belief that asymptomatic and presymptomatic transmission is much more prevalent. The early guidance was likely informed by early papers such as the two you cited, along with experience with other coronavirus such as SARS and MERS. In regard to whether presymptomatic individuals are more infectious let's take a look at the paper you linked most recently [sciencedirect.com], specifically this quote:
So, the review paper you linked actually cites another paper [nature.com] staying that the peak of infectiousness occurs prior to the onset of symptoms. Incidentally, that paper happens to be the first one I cited. So your review paper accepts it as evidence that infectiousness peaks prior to the onset of symptoms, yet you say no evidence was presented. In fact, there is evidence, and as I noted previously, the sample size from this paper is larger than from either of the two papers you referenced, meaning the margin of error should be lower.
I believe you should read the linked papers from this thread (there are five of them) again, then clarify your comments.