There are currently more than 10 million confirmed cases and more than 240,000 victims are attributed COVID-19 in the US, LSU researchers applied computational models to examine infection rates associated with social distance measures. Their paper, “Effect of mitigation measures on the distribution of COVID-19 in severely affected states in the USA,” was recently published in PLOS ONE.
This research compiles the data for each state in the US and calculates the change in the infection rate before and after social distance measures were introduced last spring.
“We are investigating the change in infection rates due to mitigation efforts and the death and infection scores up to September 2020 for some of the worst-affected states: New York, New Jersey, Michigan, Massachusetts, Illinois and Louisiana,” author Juana Moreno , LSU Department of Physics and Astronomy and the Center for Computation and Technology Associate Professor.
Many of the current predictive models of COVID-19 development, particularly after mitigation efforts, rely in part on extrapolations of data collected in other countries. However, it is important to understand the consequences of mitigation efforts based on local data, as data extracted from other areas may not be reliable. Since states and countries have implemented different degrees of social distance measures, the consequences for controlling the pandemic simply cannot be translated between regions.
‘The interaction between people is complicated and often difficult to model on an individual level. The challenge is similar to the study of a large ensemble of particles where the motion of each particle is virtually impossible. Average field approach is often used to study large populations by coarsely graining the individual, or microscopic, details of the population, or macroscopic, average quantity, ‘says lead author Ka-Ming Tam, LSU department of physics and astronomy research assistant.
With the current mitigation efforts, five of the six states, with the exception of Illinois, have reduced their base reproduction numbers to a value of less than one, which has halted the exponential growth of the pandemic.
‘The infection rate is an important indicator of the evolution of an epidemic. If it is larger than one, the number of infections increases exponentially, ”says Nicholas Walker, a former student of the Department of Physics and Astronomy at the LSU and the current postdoctoral student. ‘We have found that the infection rate is significantly suppressed by social distance measures. At the end of April, the infection rate dropped to below one in almost all countries. ”
The researchers’ analyzes show a decline in infection rates as a result of public policy measures, such as measures to remove measures and stay at home.
“We are currently working on the consequences of reopening and how reopening policies in different states have affected the number of deaths,” Moreno said. “Our current analysis suggests that the mandate for the face mask is the most important policy to reduce the number of deaths.”
Reference: “Effect of mitigation measures on the spread of COVID-19 in severely affected states in the USA” by Ka-Ming Tam, Nicholas Walker and Juana Moreno, 3 November 2020, PLOS ONE.
DOI: 10.1371 / joernaal.pone.0240877