Northwestern University presents a new global monitoring system for COVID-19

The results of a study published in the Journal of Internet Medical Research, conducted by researchers from Northwestern University in collaboration with the University of Florida, confirm that a global surveillance system for COVID-19 has been successfully developed. The system, known as GASSP, makes it possible to track the areas in which the virus is found, where it is spreading and the speed at which it is spreading, as well as whether this speed is increasing. "We can now easily identify outbreaks at the outset," says Lori Post, the project's principal investigator.   

The way the system works is identical to that used in econometrics to measure the expansion or contraction of the economy. Post notes that this is the first time this method has been used for disease monitoring and is optimistic that the model "will work efficiently.   

The systems currently in use are unable to identify epidemiological changes or warn of an impending outbreak. They have hardly changed in recent decades and essentially measure the number of cases in terms of deaths, new infections and cumulative infections. The system also monitors incomplete data using advanced statistical methods. Current surveillance systems only detect severe cases, Post said, so in the case of COVID, those figures probably only represent 10 to 20 percent of the number of cases.  

Lori Post stresses that the important thing is "to know the acceleration and how it compares from one week to the next". To this end, a measure called Jerk is used, which until now has not been used in the field of public health. "If you are the governor of New York, it is not helpful to prevent future outbreaks by looking at how many people were already infected with the coronavirus. You want to know what is happening now and what the likely scenarios are in the near future," said Post.   

"We are detecting the dynamic characteristics of the pandemic," Post said. "Pandemics move and change. We are like air traffic controllers guiding a plane during a storm. The pilot can't see. They don't know where to go, they need information. We have to guide that plane with instruments. Similarly, we must inform public health leaders when significant changes in the pandemic occur.   

A key issue for the solution of the pandemic that Post is focusing on is the so-called persistence effect. "The persistence effect measures the likelihood that people who were recently infected last week have infected others who will develop the disease this week, and who are in turn infecting others who will develop the disease next week, and so on. To flatten the curve and end the pandemic, we must reduce the effect of persistence and eventually bring it to zero". Post warns that this is a "key political objective.  

As it is a dynamic and not a static system, the information will be updated in just one second. Each U.S. Embassy will inform the respective countries of the data obtained, so they will have real-time updates. With the data provided, health systems would be prepared for rapid changes in the epidemic and governments would be able to implement timely measures to prevent and mitigate the impact of the epidemic.   

"For example, relative to other countries, the Netherlands is a small country and does not have the same number of cases as some larger countries like Spain," explained Post. "But they have alarming signs at the moment: increased speed, acceleration and positive shocks and that means potential for explosive growth," she said.   

It will also serve to prevent other negative effects from the pandemic, especially in developing countries, such as food insecurity and hospital overcrowding. It will help to understand which policies are most effective in combating the pandemic. "The system will be able to inform leaders concerned about the location of the outbreak, before it appears in hospitals and before morgues become overcrowded," Post added.  

In the United States, the system will allow the spread of the virus to be assessed at the county level, so researchers say it will not be necessary to close an entire state if it is not at risk, which will help preserve the country's economy.   

For example, Hawaii, Vermont and Maine have the lowest rate of new infections per 100,000 people per day, but the rate of spread is accelerating and the effect of persistence remains positive. For this reason they should maintain social distance, crowd control and the use of masks, because otherwise the number of cases could escalate to what is called explosive growth.