Scientists calculate incubation period of coronavirus
About 97.5 percent of people who develop symptoms will do so within 11.5 days, according to the new study.
- The incubation period of a virus is the amount of time it takes for a person to show symptoms after infection.
- A new study examined 181 cases of SARS-CoV-2 in China, finding that the mean incubation period is 5.1 days.
- The results suggest that a quarantine period of 14 days is reasonable.
It takes an average of 5.1 days for a person infected with the new coronavirus to show symptoms, according to recent research from Johns Hopkins University. Fortunately, an average incubation period of 5.1 days means that a 14-day quarantine period, which is used by the U.S. and other nations, is an appropriate amount of time to monitor people for the development of COVID-19.
"Based on our analysis of publicly available data, the current recommendation of 14 days for active monitoring or quarantine is reasonable," epidemiologist Justin Lessler from Johns Hopkins Bloomberg School of Public Health told Johns Hopkins University's HUB.That's the good news. But the findings, published March 10 in the journal Annals of Internal Medicine, also highlight one of the most pernicious aspects of the novel coronavirus: It can take days for people to realize they're infected and contagious.
Carl Court / Staff
The study estimated that the median incubation period of the SARS-CoV-2 coronavirus is 5.1 days, and that 97.5 percent of people who develop symptoms will do so within 11.5 days. However, approximately 2.5 percent of people with the virus seem to develop symptoms after 11.5 days. That means a 14-day quarantine might not be 100 percent effective. In other words, for every 10,000 people quarantined, about 101 would develop symptoms after being released, according to the researchers.
"Whether this rate is acceptable depends on the expected risk for infection in the population being monitored and considered judgment about the cost of missing cases," the researchers wrote. "Combining these judgments with the estimates presented here can help public health officials to set rational and evidence-based COVID-19 control policies."
Chung Sung-Jun / Staff
The study was based on 181 cases of COVID-19 reported in China before February 24. To create a model of incubation period distribution, the researchers looked at metrics like probable time of exposure, symptom onset, fever onset, and detection by authorities. The results showed that the incubation period of SARS-CoV-2 roughly matches that of past infectious diseases like SARS and MERS, but is a bit longer than the incubation period of the flu, which is one to four days.
Public health officials use estimates like these to determine the length of quarantines, which help to contain and track the spread of a virus. One of the most important functions of a quarantine — or really any social distancing measure — is that it helps to prevent hospitals from being overwhelmed by sick and infected patients.
If you only learn one thing about #COVID19 today make it this: everyone's job is to help FLATTEN THE CURVE. With th… https://t.co/7kEDRf1ffp— Dr Siouxsie Wiles (@Dr Siouxsie Wiles)1583692285.0
"From a US standpoint, you want to prevent any place from becoming the next Wuhan," Tom Frieden, who led the CDC under President Barack Obama, told Vox. "What that means is even if we're not able to prevent widespread transmission, we want to prevent explosive transmission and anything that overwhelms the health care system."
Slowing the spread of a virus is also referred to as flattening the curve. As Dr. Siouxsie Wiles posted on Twitter, flattening the curve is a responsibility that falls not only on government, but also on individuals. So, be sure to brush up on the best ways to prevent the contraction of the new coronavirus, and learn how it spreads from person to person.
- How likely are you to die from coronavirus? - Big Think ›
- Coronavirus: Viral video graph omits crucial information - Big Think ›
- Why public health officials sound more worried about the ... ›
- Track the coronavirus spread with this world map tool - Big Think ›
- Study: Older Americans know more about COVID than you - Big Think ›
- Study: Older Americans more knowledgeable about COVID-19 - Big Think ›
- Study: Older Americans more knowledgeable about COVID-19 - Big Think ›
What would happen if you tripled the US population? Join Matthew Yglesias and Charles Duhigg at 1pm ET on Monday, September 28.
Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
Dominique Crenn, the only female chef in America with three Michelin stars, joins Big Think Live.
Having been exposed to mavericks in the French culinary world at a young age, three-star Michelin chef Dominique Crenn made it her mission to cook in a way that is not only delicious and elegant, but also expressive, memorable, and true to her experience.
New experiments find weird quantum activity in supercold gas.
Quantum Mechanics, Onions, and a Theory of Everything<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="036ae7b8dd661df2d125a3421a0299ba"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/bcVruA0AJ-o?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Researchers say that moral self-licensing occurs "because good deeds make people feel secure in their moral self-regard."
Books about race and anti-racism have dominated bestseller lists in the past few months, bringing to prominence authors including Ibram Kendi, Ijeoma Oluo, Reni Eddo-Lodge, and Robin DiAngelo.