Chaos theory is used by mathematicians and physicists to explain the behavior of certain dynamical systems that vary over time and are usually very sensitive to any variation in the starting conditions. An example of these systems is the fluctuation of temperatures: it is very difficult to make predictions of the weather next week. The spread of infections can also be studied based on chaos theory, and this is what a team of scientists has done to analyze, with data updated until March 27, the spread of the virus and the most effective strategies at the level. universal to stop the progression of COVID-19 disease.
The results revealed that the virus grows following a potential type curve, in which characteristics as varied as the social, economic and geographical characteristics of each area affect the speed at which it spreads. In fact, these variables influence much more than the traits of the infection itself.
In order to identify effective strategies at a universal level, the researchers analyzed data from nine countries on different continents: Brazil, China, France, Germany, Italy, Japan, South Korea, Spain and the United States. “We decided to take advantage of our experience in numerical analysis and use a series of real-time data from the accumulated confirmed cases of COVID-19 to seek answers about the spread of this pathogen,” explains Cesar Manchein, one of the authors. The scientists used the technique of numerical modeling, which takes advantage of the power of computation to solve a set of differential equations that allow comparing groups of data and validating proposed models based on observations.
Two effective measures in all the countries studied
The results, which are published in the journal Chaos , revealed that social distancing measures and conducting massive tests to identify and quarantine asymptomatic cases have been the most effective generic strategies to stop the spread of SARS-CoV- two. Softer confinement measures, they say, are less effective at flattening curves compared to more stringent isolation guidelines.
This combination of two actions (social isolation measures and testing) has basically been the strategy followed in South Korea, a country that has managed to keep the epidemic at reasonable levels so as not to make its health systems collapse.
Objective: improve predictions
The researchers plan to continue applying new data to the model to improve its accuracy and, most importantly, its predictability. One of the applications of these models would be to test different strategies that can avoid long quarantines.
“Researchers in physics and chaos theory can play a critical role in the battle against coronavirus,” explains Manchein. “From a theoretical point of view, we can use our knowledge and experience to study the time and territorial evolution of the disease.”
Reference: Manchein et al. 2020. “Strong correlations between power-law growth of COVID-19 in four continents and the inefficiency of soft quarantine strategies,” Chaos (DOI: 10.1063 / 5.0009454).
Photo: Cumulative number of confirmed COVID-19 infected cases as a function of time for nine countries, excluding days with fewer than 100 infected.
