Pandemics with the same level of impact as COVID-19 have a chance of about 2% occurring each year. Each individual has a 38% chance of experiencing a COVID-19 equivalent pandemic at least once in a lifetime.
"The most important thing is that major pandemics like COVID-19 and the Spanish flu are relatively likely to occur," Duke University's global environmental health researcher William Pan was quoted as saying by Science Alert on Wednesday (25/8/2021).
The research team looked at the historical record of the epidemic from 1600 to the present. They found there were 476 documented epidemics, about half of which had a recorded number of victims.
About 145 of them caused less than 10,000 deaths, while 114 other epidemics we only know of, but there is no record of the number of deaths.
In this study, the team used detailed modeling with a common Pareto distribution to analyze the data, finding that the number of annual epidemics varied greatly, and extreme epidemics such as the Spanish flu of 1918-1920 had a probability of occurring somewhere between 0.3% to 1%. , 9% over the last 400 years.
The prediction is not a stable probability, but continues to grow. In the last 50 years, we have seen increasing levels of new pathogens spreading through humans. SARS-CoV-2 is the most obvious example. But in addition, in the last few decades we have also experienced swine flu, bird flu, Ebola, and more.
"With recent estimates of increased disease incidence rates from animal reservoirs associated with environmental change, these findings suggest the likelihood of a COVID-19-like pandemic (whose probability of experiencing it in a lifetime is currently about 38 percent), may double in some the next decade, "said William.
So, even when we later recover from the current COVID-19 pandemic, it is important not to assume that we are safe and will not encounter another pandemic in the near future.
If we play our part properly and handle the COVID-19 pandemic well, then our responses and resources can learn a lot and prepare for the next pandemic.
"This demonstrates the importance of early response to disease outbreaks and capacity building for pandemic surveillance on a local and global scale, as well as for setting a research agenda to understand why large outbreaks will become more common," William said.
He added that current pandemics are often due to extreme population growth, changes in the food system, environmental degradation and more frequent contact between humans and disease -carrying animals.
That said, the statistical analysis they do only seeks to characterize risk, not to explain what drives it. They hope the study will trigger a deeper exploration of the reasons.
"This research is a signal for the importance of early response to possible extreme disease outbreaks while building the ability to monitor for possible pandemics at the local and global levels," he concluded.