Severe undercount of COVID-19 cases in USA, other countries are estimated according to model

In a new machine learning framework, reported test results and mortality rates are used to calculate the calculations of current COVID-19 infections in all 50 US states and 50 countries. Jungsik Noh and Gaudenz Danuser of the University of Texas Southwestern Medical Center present these findings in the open-access journal PLOS ONE on February 8, 2021.

During the ongoing pandemic, U.S. states and many countries reported the daily count of COVID-19 infections and deaths confirmed by tests. However, many infections have not been detected, leading to an understatement of the total number of people currently infected at any given time – an important measure to target public health efforts.

Now, Noh and Danuser have developed a computational model that uses machine learning strategies to estimate the actual daily number of current infections for all 50 U.S. states and the 50 most infected countries. To make the calculations, the model uses previously published pandemic parameters and daily data available on confirmed cases and deaths. Visualizations of these daily estimates are available for free.

The estimates of the model indicate serious undercutting of issues in the US and worldwide. The cumulative number of actual cases in 9 out of 50 countries is estimated to be at least five times higher than confirmed cases. Within the US, estimates of the cumulative number of actual cases in states were consistent with the results of an antibody study conducted in 46 states.

In some countries, such as the US, Belgium and the UK, estimates indicate that more than 20 per cent of the total population has experienced infection. As of January 31, 2021, some U.S. states – including Pennsylvania, Arizona and Florida – currently have active businesses that make up more than 5 percent of the state’s entire population. In Washington, active cases are estimated at one percent of the population that day.

Looking ahead, the model is estimating current COVID-19 case counts within communities, which could help inform contact tracing and other public health efforts.

The authors add: ‘Since the confirmed cases only capture the tip of the iceberg in the middle of the pandemic, the estimated size of current infections in this study provides important information to determine the severity of COVID-19 which can be misled by the confirmed cases. ‘