‘Diseases are increasingly jumping from animals to humans: greater risk of pandemic’

Animal diseases spread to humans much more often than before. The risk of a new pandemic that is dangerous to humans is therefore also increasing. This is evident from a study in the scientific journal BMJ Global Health publishes.

A pandemic like corona is not a coincidence or stupid bad luck. Such an outbreak of a zoonosis, an animal disease that spreads to humans, fits into a much broader picture. “Recent epidemics follow a multi-decade trend in which outbreaks have become both larger and more frequent,” four California scientists concluded in a study published last week. And this trend also means that the risk of pandemics continues to increase.

The researchers are affiliated with Concentric by Ginkgo, a company that helps governments identify epidemics early. In this study, they worked with an extensive database of more than 3,000 epidemics in the period from 1963 to 2019. They specifically looked at five zoonoses that – in short – are so serious that outbreaks have been well documented. The Ebola virus and Sars-Cov-1, a genetic predecessor of the recent coronavirus, are the best known. The researchers identified 75 outbreaks, which killed a total of more than 17,000 people. Those outbreaks occurred in 24 different countries in Africa, Asia and South America.

Both the number of outbreaks and the number of deaths were found to increase exponentially over the 56-year period studied. Until the 1990s, there was only one year (1976) with more than one outbreak. Since 1994, only four times have there been fewer than two outbreaks in a year. The severity of these outbreaks is also increasing: more recent outbreaks claim many more lives, the researchers note.

Ebola in 2013

There is, however, a caveat to this. The Ebola outbreak in West Africa (2013) claimed more than 11,000 lives, roughly two-thirds of the total deaths from the 75 epidemics in the study. Yet the overall picture – a sharply increasing number of outbreaks and deaths – remains intact even if that outlier were to be ignored.

The corona pandemic is not covered by the research. If it were to count, it would reduce every other outbreak to a ripple in the pond. The World Health Organization (WHO) estimated last year that Covid-19 has killed around 15 million people worldwide. Seen in this light, the 2013 Ebola outbreak is not an outlier, the scientists indicate. With the growth in both the number of outbreaks and the number of deaths, the chance of such peaks also increases.

Measures necessary

If the trend of recent decades continues, outbreaks of the investigated zoonoses will occur four times as often in 2050 as in 2020. And they will claim twelve times as many lives, although that figure is relative after the corona pandemic: Covid-19 After all, it caused almost a thousand times as many deaths as all other outbreaks in the study combined.

Measures are “urgently needed” to address this “major and growing risk to global health,” the researchers write. This study does not discuss which measures exactly these are. The researchers do indicate that the corona pandemic has already increased awareness among governments: they have already taken various measures to detect and contain epidemics more quickly.

They also point to the ultimate source of zoonoses: contact between humans and animals. The risks of intensive livestock farming are already regularly highlighted. But the damage to habitats due to deforestation and climate change can also cause viruses to jump more quickly from animals to humans.