Modeling COVID-19 Data Must Be Done With Extreme Care

At the beginning of a new wave of an epidemic, extreme care should be used when extrapolating data to determine whether lockdowns are necessary.
American Institute of Physics (AIP)

Newswise — WASHINGTON, May 19, 2020 -- As the infectious virus causing the COVID-19 disease began its devastating spread around the globe, an international team of scientists was alarmed by the lack of uniform approaches by various countries’ epidemiologists to respond to it.

Germany, for example, didn’t institute a full lockdown, unlike France and the U.K., and the decision in the U.S. by New York to go into a lockdown came only after the pandemic had reached an advanced stage. Data modeling to predict the numbers of likely infections varied widely by region, from very large to very small numbers, and revealed a high degree of uncertainty.

Davide Faranda, a scientist at the French National Centre for Scientific Research (CNRS), and colleagues in the U.K., Mexico, Denmark, and Japan decided to explore the origins of these uncertainties. This work is deeply personal to Faranda, whose grandfather died of COVID-19; Faranda has dedicated the work to him.

In the journal Chaos, from AIP Publishing, the group describes why modeling and extrapolating the evolution of COVID-19 outbreaks in near real time is an enormous scientific challenge that requires a deep understanding of the nonlinearities underlying the dynamics of epidemics.

Forecasting the behavior of a complex system, such as the evolution of epidemics, requires both a physical model for its evolution and a dataset of infections to initialize the model. To create a model, the team used data provided by Johns Hopkins University’s Center for Systems Science and Engineering, which is available online at https://systems.jhu.edu/research/public-health/ncov/ or https://github.com/CSSEGISandData/COVID-19.

“Our physical model is based on assuming that the total population can be divided into four groups: those who are susceptible to catching the virus, those who have contracted the virus but don’t show any symptoms, those who are infected and, finally, those who recovered or died from the virus,” Faranda said.

To determine how people move from one group to another, it’s necessary to know the infection rate, incubation time and recovery time. Actual infection data can be used to extrapolate the behavior of the epidemic with statistical models.

“Because of the uncertainties in both the parameters involved in the models -- infection rate, incubation period and recovery time -- and the incompleteness of infections data within different countries, extrapolations could lead to an incredibly large range of uncertain results,” Faranda said. “For example, just assuming an underestimation of the last data in the infection counts of 20% can lead to a change in total infections estimations from few thousands to few millions of individuals.”

The group has also shown that this uncertainty is due to a lack of data quality and also to the intrinsic nature of the dynamics, because it is ultrasensitive to the parameters -- especially during the initial growing phase. This means that everyone should be very careful extrapolating key quantities to decide whether to implement lockdown measures when a new wave of the virus begins.

“The total final infection counts as well as the duration of the epidemic are sensitive to the data you put in,” he said.

The team’s model handles uncertainty in a natural way, so they plan to show how modeling of the post-confinement phase can be sensitive to the measures taken.

“Preliminary results show that implementing lockdown measures when infections are in a full exponential growth phase poses serious limitations for their success,” said Faranda.

###

The article, “Asymptomatic estimates of SARS-CoV-2 infection counts and their sensitivity to stochastic perturbation,” is authored by Davide Faranda, Isaac Pérez Castillo, Oliver Hulme, Aglaé Jezequel, Jeroen Lamb, Yuruzu Sato, and Erica L. Thompson. It will appear in Chaos, May 19, 2020 (DOI: 10.1063/5.0008834). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0008834.

ABOUT THE JOURNAL

Chaos is devoted to increasing the understanding of nonlinear phenomena in all areas of science and engineering and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See https://aip.scitation.org/journal/cha.

###

SEE ORIGINAL STUDY



Filters close

Showing results

110 of 5853
Newswise: First Wave COVID-19 Data Underestimated Pandemic Infections
18-Jun-2021 8:30 AM EDT
First Wave COVID-19 Data Underestimated Pandemic Infections
American Institute of Physics (AIP)

Two COVID-19 pandemic curves emerged within many cities during the one-year period from March 2020 to March 2021. Oddly, the number of total daily infections reported during the first wave is much lower than that of the second, but the total number of daily deaths reported during the first wave is much higher than the second wave.

Newswise: PNNL AI Expert Harnesses Open-Source Data to Understand Human Behavior
Released: 22-Jun-2021 9:55 AM EDT
PNNL AI Expert Harnesses Open-Source Data to Understand Human Behavior
Pacific Northwest National Laboratory

PNNL researchers used natural language processing and deep learning techniques to reveal how and why different types of misinformation and disinformation spread across social platforms. Applied to COVID-19, the team found that misinformation intended to influence politics and incite fear spreads fastest.

Released: 22-Jun-2021 8:30 AM EDT
Engineering Nanobodies As Lifesavers When SARS-CoV-2 Variants Attack
Ohio State University

Scientists are pursuing a new strategy in the protracted fight against the SARS-CoV-2 virus by engineering nanobodies that can neutralize virus variants in two different ways.

Released: 21-Jun-2021 3:45 PM EDT
Rare Neurological Disorder Documented Following COVID-19 Vaccination
American Neurological Association (ANA)

In two separate articles in the Annals of Neurology, clinicians in India and England report cases of a rare neurological disorder called Guillain-Barré syndrome after individuals were vaccinated against COVID-19.

Newswise: New Analysis reveals link between birthdays and COVID-19 spread during the height of the pandemic
17-Jun-2021 12:10 PM EDT
New Analysis reveals link between birthdays and COVID-19 spread during the height of the pandemic
Harvard Medical School

Risk of SARS-CoV-2 infection increased 30 percent for households with a recent birthday in counties with high rates of COVID-19 Findings suggest informal social gatherings such as birthday parties played role in infection spread at the height of the coronavirus pandemic No birthday-bash infection jumps seen in areas with low rates of COVID-19 Households with children’s birthdays had greater risk of SARS-CoV-2 infection than with adult birthdays

Newswise: COVID-19 dual-antibody therapies effective against variants in animal study
Released: 21-Jun-2021 10:05 AM EDT
COVID-19 dual-antibody therapies effective against variants in animal study
Washington University in St. Louis

A study from Washington University School of Medicine in St. Louis suggests that many, but not all, COVID-19 therapies made from combinations of two antibodies are effective against a wide range of virus variants, and that combination therapies appear to prevent the emergence of drug resistance.

13-Jun-2021 12:05 PM EDT
COVID-19 Pandemic Drinking: Increases Among Women, Black Adults, and People with Children
Research Society on Alcoholism

Risky drinking has been a public health concern in the U.S. for decades, but the significant increase in retail alcohol sales following COVID-19 pandemic stay-at-home orders in particular raised red flags for alcohol researchers. New research has assessed changes in alcohol drinking patterns from before to after the enactment of stay-at-home orders. These results and others will be shared at the 44th annual scientific meeting of the Research Society on Alcoholism (RSA), which will be held virtually this year from the 19th - 23rd of June 2021 due to the COVID-19 pandemic.

13-Jun-2021 1:05 PM EDT
The Impact of the COVID-19 Pandemic on Alcohol Consumption Is Far From ‘One Size Fits All’
Research Society on Alcoholism

An ongoing analysis of the effects of the COVID-19 pandemic on alcohol and related outcomes shows that COVID-related stressors experienced by study participants – including work-, financial-, and family-related stressors – are having a varied impact on individuals with and without alcohol use disorders (AUDs). These results will be shared at the 44th annual scientific meeting of the Research Society on Alcoholism (RSA), which will be held virtually this year from the 19th - 23rd of June 2021 due to the COVID-19 pandemic.

Newswise:Video Embedded newswise-expert-panels-on-covid-19-pandemic-notable-excerpts-quotes-and-videos-available
VIDEO
Released: 18-Jun-2021 2:10 PM EDT
Newswise Expert Panels on COVID-19 Pandemic: Notable excerpts, quotes and videos available
Newswise

Newswise is hosting a series of Expert Panels discussion on unique aspects of the COVID-19 pandemic. This tip sheet includes some notable quotes from the panelists.

access_time Embargo lifts in 2 days
Embargo will expire: 23-Jun-2021 8:00 AM EDT Released to reporters: 18-Jun-2021 11:00 AM EDT

A reporter's PressPass is required to access this story until the embargo expires on 23-Jun-2021 8:00 AM EDT The Newswise PressPass gives verified journalists access to embargoed stories. Please log in to complete a presspass application. If you have not yet registered, please Register. When you fill out the registration form, please identify yourself as a reporter in order to advance to the presspass application form.


Showing results

110 of 5853

close
1.19376