That's sick! Humans identify infected peers from a photo

January 3, 2018
That's sick! Humans identify infected peers from a photo
Scientists combined 16 photo portraits into one composite image. On the left, the composite “sick” face, and on the right, the composite healthy one. Credit: Audrey Henderson/St Andrews University

Human beings can spot a sick person, on a photo, a mere two hours after he or she was infected by a germ, researchers said Wednesday.

Such an ability to detect infection early, and from the subtlest of facial clues, has never been demonstrated before, but is presumed to be part of a crucial survival skill called "disease avoidance", they wrote.

"An ability to detect sick people would allow people to avoid being close to sick people, and hence minimise the risk of becoming sick if the person is a carrier of contagious disease," study co-author John Axelsson of Stockholm University told AFP.

The research team experimented with 16 healthy volunteers, all Caucasian.

Each was given a shot of lipopolysaccharides (LPS)—molecules taken from bacteria.

The LPS molecules are sterile, meaning that no live bacteria is injected. But they cause a strong immune response and flu-like symptoms that lasts a few hours—mimicking someone who is "acutely sick" and fighting off infection.

It is a method commonly used to cause infections in humans and people for experimentation purposes.

On a second occasion, each participant received a placebo or "dummy" injection.

The volunteers had their photo taken about two hours after each shot—thus once in a healthy state after receiving the placebo, and once "sick".

After the LPS shot, some of the participants "felt very sick and others did not feel much sick at all" when their photo was taken, Axelsson explained.

Both pictures, healthy and sick, of all participants were then showed to a different group of people, which had to rate whether the person was sick or healthy.

Paler lips

"The raters could correctly discriminate 13 out of 16 individuals (81 percent) as being sick," said the study published in the journal Proceedings of the Royal Society B.

This was at a rate higher than predicted by pure chance alone.

Previous research had used photos of "obviously sick people" to induce disgust, anxiety and even an in people, but the participants in the latest study were photographed with neutral expressions and very shortly after infection.

There was thus no sneezing, coughing or other overt symptoms of sickness on display.

The results suggested that "humans have the ability to detect signs of illness in an early phase after exposure to infectious stimuli," the study authors concluded.

Sick individuals were rated by observers as having paler lips and skin, a more swollen face, droopier mouth corners and eyelids, redder eyes, and duller, patchier skin.

The finding could "help medical doctors and computer software to better detect sick ," said Axelsson—a potentially valuable diagnostic tool in a disease outbreak.

Further study is needed to determine whether levels of detection are similar across diseases and ethnic groups.

Explore further: When a cold or flu strikes a family member

More information: Identification of acutely sick people and facial cues of sickness, Proceedings of the Royal Society B, rspb.royalsocietypublishing.or … .1098/rspb.2017.2430

Related Stories

When a cold or flu strikes a family member

September 21, 2017
(HealthDay)—When one child gets sick, you might brace yourself for everyone getting sick. But it's possible to keep healthy family members from falling ill, too.

Double-blind study suggests humans have olfactory defense against contagious disease

May 24, 2017
(Medical Xpress)—A European team of researchers working at Sweden's Karolinska Institutet has found evidence that suggests that humans have an olfactory defense against contagious diseases. In their paper published in Proceedings ...

Two percent of US employees go to work each week despite being sick

March 7, 2016
Each week, up to three million US employees go to work sick, with roughly half of these incidents due to a lack of paid leave coverage. The findings come from an analysis of information from the 2011 Leave Supplement of the ...

Animals conceal sickness symptoms in certain social situations

June 18, 2014
Animals have the ability to conceal their sickness in certain social situations. According to a new review, when given the opportunity to mate or in the presence of their young, sick animals will behave as though they were ...

A change of job could help people on long-term sick leave

April 26, 2016
A change of job could be a means of prolonging labour market participation for people on long-term sick leave, according to a thesis by Karin Nordström at Karolinska Institutet. The thesis also looks at differences in sick ...

Recommended for you

Mammary stem cells challenge costly bovine disease

April 24, 2018
Mastitis is the most expensive disease in the dairy industry. Each clinical case can cost a dairy farmer more than $400 and damages both the cow's future output as well as her comfort.

Research explains link between exercise and appetite loss

April 24, 2018
Ever wonder why intense exercise temporarily curbs your appetite? In research described in today's issue of PLOS Biology, Albert Einstein College of Medicine researchers reveal that the answer is all in your head—more specifically, ...

Fruit fly study identifies new gene linked to aortic aneurysms

April 24, 2018
An interdisciplinary team of researchers has identified a new gene linked to human aortic aneurysms. By combining comprehensive genetic studies in the fruit fly, dataset searches and analysis of diseased human aortic tissue, ...

Scientists manipulate 'satellite cells' to speed healing

April 24, 2018
Muscle aches and pains, whether from stretching, strenuous exercise or just normal wear and tear, can put a crimp in your day, a limp in your step and be an actual pain in the neck. But no matter the severity, stem cells ...

Advanced sensor to unlock the secrets of the brain

April 24, 2018
Researchers have announced the development of a state-of-the-art sensor that can for the first time detect signalling molecules, called cytokines, which operate in the living brain. Cytokines in the brain are secreted by ...

New cell therapy aids heart recovery—without implanting cells

April 23, 2018
Heart disease is a major global health problem—myocardial infarction annually affects more than one million people in the U.S. alone, and there is still no effective treatment. The adult human heart cannot regenerate itself ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Ojorf
not rated yet Jan 03, 2018
Now train an AI with pics of sick people.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.