Tracking the Spread of COVID-19 with Air Travel Data
An image from the RAND model shows sources of COVID-19 risk for the United States
Prototype Model Visualizes Risk Associated with Air Travel Routes
The COVID-19 Air Traffic Visualization (CAT-V) tool combines case data from Johns Hopkins University with detailed air travel data from the International Air Transport Association. Together, these data sets make it possible to visualize how coronavirus disease 2019 (COVID-19) infections and commercial air travel have interacted to export infection risk across the world. Given air travel data and reported infection rates, our tool can also be used to estimate future patterns of COVID-19 transmission. As a result, policymakers, analysts, and others can estimate the impact of travel-related policy interventions, such as restricting air travel from various countries.
The CAT-V tool offers a "heat map" feature and the ability to visualize the risk associated with individual air travel routes. The tool is currently an internal prototype model being refined for possible public release. We will continue to develop and use the CAT-V tool in new ways, and we will continue to release a stream of derivative findings on topics of interest to policymakers. The first set of findings, below, includes an introduction to the CAT-V tool, an estimate of the rate at which reported cases were being exported from China by the end of January 2020, an estimate of the rate at which cases were being underreported in China that same month, an estimate of the greatest source of importation risk to the United States in late February 2020, and the probable origin of cases in Gulf Cooperation Council countries.
In September 2020, RAND released two new reports describing the spread of COVID-19 before it was declared a pandemic, and the drivers of COVID-19 risk in Africa.
Researchers combine case data from Johns Hopkins University with detailed air travel data from the International Air Transport Association to visualize how COVID-19 infections and commercial air travel have interacted to export infection risk across the world.
Based on officially reported cases in China in January 2020, the odds of the novel coronavirus appearing by January 22, 2020, in Japan, Thailand, South Korea, the United States, and Taiwan—as it did—would have been minuscule.
Countries with modest numbers of confirmed cases can still represent the greatest risks of virus exportation to the United States if those countries have relatively high active case rates per capita and high levels of connectivity to the United States.
Worldwide exports of COVID-19 cases began increasing at an accelerating rate on February 19, 2020. That was three weeks before the World Health Organization declared the pandemic. By the end of February, nearly 40 cases per week were spreading around the globe via air travel.
U.S. forces in Africa are usually in areas of instability and thus have low levels of international air travel. Those regions are less likely to import COVID-19. The near-term driver of COVID-19 risk in Africa will more likely be the flow of travelers from Western Europe to Morocco, South Africa, and Algeria.
Sep 22, 2020
Audiences of Interest
Reports based on the CAT-V tool will be of interest to U.S. Department of Defense policymakers and planners at the strategic and operational levels. At the strategic level, projections of how COVID-19 is likely to propagate across the world can inform defense-related decisions on global deployment pathways and timing, force health protection measures, and emerging risks that competitors may exploit infection patterns for strategic advantage. At the operational level, the projections can inform
theater assessments of where COVID-19 stress may increase the likelihood of political crises that threaten U.S. diplomatic and other facilities
the viability of contingency operating locations required to respond to those crises
the impacts of COVID-19 restrictions on deployment timelines for crisis response forces.
The tool and associated reports will also be of interest to U.S. policymakers and planners in other fields, such as foreign policy, public health, transportation, and homeland security.