Study Predicts a 12-Fold Increase in Deaths from Zoonotic Viruses by 2050

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Study Predicts a 12-Fold Increase in Deaths from Zoonotic Viruses by 2050

Over the past four years, it has become clear to anyone on Earth that under the right conditions, zoonotic viruses capable of cross-species evolution can quickly become a severe global crisis.

While COVID-19 was a rare “perfect storm” of zoonotic virus transmission, international researchers believe we are now in a startling new era where zoonotic viruses are infecting humans at an alarming rate.

Study Predicts a 12-Fold Increase in Deaths from Zoonotic Viruses by 2050

Researchers conducted a comprehensive study of epidemiological data spanning 60 years and found concerning trends in human infections from zoonotic diseases, with both incidence and morbidity growing at an “exponential rate.”

Researchers at Gingko Bioworks, a US biotechnology organization, pointed out, “Newly emerging zoonotic viruses subsequently spread from person to person, which is the focus of this analysis since they account for 60% of the etiology of most epidemics in the 20th century.”

Using a series of datasets, they analyzed 3,150 zoonotic disease outbreaks and epidemics that occurred from 1963 to 2019, searching for trends in infections and fatalities. They were particularly interested in viruses with COVID-19-style “perfect storm” potential for exponential spread, as these viruses pose the greatest risks to public health, the economy, and political stability.

They identified 75 zoonotic virus spillover events in 24 countries, resulting in 17,232 deaths. Notably, 15,771 deaths occurred in 40 outbreaks caused by filamentous viruses, including Ebola and Marburg viruses, which are among the confirmed “bad actor” pathogens. The other three pathogens are SARS Coronavirus 1, Nipah virus, and Machupo virus.

They estimated, “If this annual growth rate continues, we expect the spillover events and deaths caused by the analyzed pathogens in 2050 to be four times and twelve times greater, respectively, than in 2020.”

While COVID-19 is an outlier among zoonotic diseases and has been excluded from the data, the numbers of spillover events and reported deaths from the four virus classes increased by 4.98% and 8.7% annually from 1963 to 2019.

The researchers wrote, “Our assessment of historical evidence suggests that recent zoonotic spillover-driven epidemics are not isolated or random clusters but rather follow a decades-long trend of increasing epidemic scale and frequency.”

Nipah virus, which accumulates in fruit bats or fox bats, can cause encephalitis and range from mild to fatal. Similarly, fox bats are considered a natural reservoir for the Ebola virus.

Severe Acute Respiratory Syndrome (SARS) coronaviruses are also believed to have jumped from bats to humans.

Study Predicts a 12-Fold Increase in Deaths from Zoonotic Viruses by 2050

The Machupo virus is a highly infectious hemorrhagic fever and is considered a cousin of the Ebola virus, which jumped to humans in Bolivia in the 1950s due to increased interaction with wild rodents known as Calomys.

While zoonotic virus outbreaks have been isolated in the past and largely controlled, the increasing frequency and severity, with few notable exceptions, have scientists deeply concerned.

More concerning is that detailed historical data on virus outbreaks are fragmented and scarce, making it difficult to model for future epidemics or more severe pandemics.

The researchers pointed out, “The ultimate package of measures supporting global prevention, preparedness, and recovery remains unclear. However, the trends from historical evidence suggest that urgent action is needed to address the substantial and growing risks to global health.”

Scientists are further studying the range and evolution of monkeypox virus or MPXV (formerly known as smallpox, as it is likely transmitted from rodents rather than monkeys), and avian influenza H5N1 may switch its favorite host from birds to mammals.

Zoonotic pathogens can be bacteria, viruses, or parasites that can be transmitted to humans through direct contact or through food, water, or the environment. According to the World Health Organization, there are over 200 known zoonotic diseases, or diseases that can be transmitted from animals to humans.

Looking at historical trends, it is clear that urgent action is needed to address the substantial and increasingly growing risks to global health. This study was published in the “BMJ Global Health” journal.