This trick may have stopped Covid-19 throughout the country

When Covid-19 first appeared in Chile, how it spread gave scientists a unique opportunity to observe how the disease travels beyond a country with an unusual shape. The geography of Chile – narrow and narrow – plays an important role in the way the virus is prevalent. The way viruses move is more than just places people go or rules set. It also follows a pattern similar to a natural system, where small changes in one area lead to greater impact on the entire system. In a country like Chile, know when the disease has changed from a local outbreak to a national crisis.

Professor Mauricio Canal from the University of Chile carefully studied the process. He used a mathematical model called the Logistic model that describes how growth starts slowly, speeds up and then closes. He also applied something called the osmosis theory, which examines how things like fluids or diseases move in connected spaces to understand how Covid-19 spreads throughout Chile. His research, published in the journal Cureus, involves simulating the country’s grid in local administrative regions. This helped him see how the number of infections and the connections of the region affected the growth of the pandemic.

In the simulation, when only a small number of communes were infected, the virus did not spread throughout the country. The spread remains fragmented. But once most communes have cases, the virus can move freely without any gaps. Real-world data confirms this: Once the virus reaches enough location, it becomes extremely difficult to prevent it from spreading everywhere.

An important gain of this work is how well the logical model matches what actually happens. It shows that even smaller communes have no viruses and may have avoided spread across the country. “The logical model of epidemic spatial transmission allows for an estimate of the time to reach the threshold, which forms a window into which mitigation or control measures can be implemented,” Professor Canals said. In this case, the threshold is a key point where small changes can lead to larger, broader effects. His estimates are very much in line with the moment the country really crosses the tipping point and provides valuable early warning tools.

This is not only the theory of researchers. It has realistic importance. It shows how to block viruses in critical areas from blocking their wider spread. Chile’s long-lasting shape makes it an ideal place to test this idea. If some central regions remain healthy, especially those spread across the country from east to west, they may be like natural obstacles to fight the spread of the virus.

Professor Canal also explains how geography affects the early stages of the outbreak. The virus first appears in the north, center and south, forming separate clusters. These clusters grow gradually and eventually join a large infection zone. Some small, distant communes avoid infections for a while, but overall they are not stopped because they are small and allow people to come in and out. Grid-based models (simplified map pattern simulations representing space and movement) were run thousands of times and showed that the chance of national spread increased dramatically when a large number of communes occupy cases.

Finally, this study supports the use of such models to understand and plan the epidemic. They can help predict when situations get out of control and show where to focus their prevention efforts. “It is proven that the vast majority of communes that need infection are to be affected,” Professor Canals said. This insight helps public health officials develop smart, centralized strategies to slow or stop the spread of the disease in the future.

Journal Reference

Canals M. “Spatiotemporal analysis of the spread of the Chilean epidemic using penetration models.” Cureus, 2025; 17(3):E80468. doi:

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