Israeli researchers say wearable sensors could cut spread of contagious disease
Tel Aviv University-led team finds that technology that warns of illness 1 to 3 days before appearance of symptoms might prevent future pandemics and help timely disease management
Reporter at The Times of Israel
Researchers at Tel Aviv University say that smartwatches with biomarkers that provide early detection of contagious diseases can prevent the spread of infections and even preempt global pandemics in the future.
“Early diagnosis can be critical for inducing behavioral changes, such as reduced social contacts, when the disease is most infectious,” said Prof. Dan Yamin, head of the Lab for Digital Epidemiology and Health Analytics, and Prof. Erez Shmueli, head of the Big Data Lab, both at Tel Aviv’s industrial engineering school, who led the team of researchers in Israel and at Stanford University.
The two-year study, which focused on three infectious diseases — COVID-19, influenza, and group A streptococcus (GAS) — was published last month in the prestigious peer-reviewed scientific journal Lancet Regional Health – Europe.
The researchers also discovered that even after people reported their first symptoms, they postponed testing. During this critical period, they were spreading the disease to others.
The findings highlight a significant gap in timely disease management, the researchers said, and can help improve public health strategies.
The researchers likened the spread of infectious diseases to controlling the spread of wildfires, as in both cases early detection is crucial.
Nearly all infectious diseases begin silently and progressively worsen until clinical symptoms appear. During this period, people decide how to modify their social activities and when to seek diagnostic tests and treatment.
During the study, 4,795 Israelis over 18 years of age wore a smartwatch that continuously monitored key physiological parameters, including pulse and heart rate.
These biomarkers reveal information about our body’s two most important systems: the heart and the brain, said Yamin.
“When a person becomes ill, most of the focus goes to the immune system that is battling the disease,” he said. “Our brain constantly consumes energy, burning oxygen provided by the cardiovascular system, and consequently, any change in our activity or condition is immediately reflected in a change in our heart rate.”
In addition to wearing the smartwatches, the participants answered a daily series of questions about how they felt physically and mentally, including if they felt any specific symptoms.
They also received home test kits for the three diseases, which they used at their discretion.
Over the two years, the researchers collected 800,000 questionnaires; this data was compared with parallel data from the smartwatch.
Altogether, the data included 490 episodes of influenza, 2,206 episodes of COVID-19, and 320 episodes of GAS.
The researchers then built special models that identified the three points in time following exposure to an infectious disease.
With COVID-19, for example, the patient’s heart rate changed 96 hours after exposure, yet it took another 34 hours for the person to notice symptoms. Then, it took 64 more hours for them to use the home test confirming the disease.
“Consequently, for quite a long interval, from exposure to testing, they did not change their social behavior, spreading the disease to others,” said Shmueli.
“We found that on average, people performed the test and changed their behavior when the disease was already past its peak” and the chance of infecting others was lower, Shmueli said.
The subjects also waited 68 hours on average before they tested themselves for influenza and 58 hours for GAS.
“The delay between digital diagnosis and testing is thus extremely crucial,” Shmueli said.
Using digital diagnosis can significantly reduce the spread of infectious diseases because people might change “their social behavior at a much earlier stage of the disease,” Yamin said.
If this happens, then people with COVID, who normally infect an average of three people, would infect less than one other person.
If “every sick individual transmits the disease to less than one other person, the disease soon dies out,” he said, effectively eliminating the next pandemic.
Early detection is the most effective
Early diagnosis is also critical for effective treatment, the researchers said.
Existing treatments for COVID-19, for instance, are very effective only when given early on, preventing severe illness, hospitalization, and even death.
“Infectious diseases pose the greatest threat for a global catastrophe,” Yamin said. People travel all over the world and potentially spread new diseases.
“Modern technology can help us combat this danger and devise more effective public health strategies,” the researchers said.
“Smartwatches are a relatively new technology, with enormous potential,” said Yamin. “There are ever more sensitive and accurate wearable sensors constantly being developed. Ultimately, this can be a high-impact tool for preempting future pandemics.”
