Over the past 50 years, cases of virus transmission from mammals and birds to humans have increased significantly, according to a study published in the British journal BMJ Global Health.
Between 1963 and 2019, 75 episodes of zoonoses occurred in 24 countries, write the authors of the study, researchers from the American biotechnology company Ginkgo Bioworks. More than 3,150 outbreaks were studied.
Researchers have focused only on four classes of viruses: filoviruses (Ebola, Marburg virus), severe acute respiratory syndrome coronavirus (SARS-CoV-1), Nipah virus and Machupo virus, responsible for hemorrhagic fever in Bolivia.
During the studied period, these zoonotic diseases caused a total of 17,232 deaths, the majority of which (15,771) were caused by filoviruses, which can cause severe hemorrhagic fever in people and non-human primates (such as monkeys and gorillas), mainly in Africa, according to the study.
Worrying Forecasts for 2050
These four types of infections from animals to humans have been increasing at an "exponential rate." Based on the study, by 2050 these infections could cause 12 times more deaths than in 2020.
"If these annual rates of increase continue, we would expect the analyzed pathogens to cause four times the number of spillover events and 12 times the number of deaths in 2050 than in 2020," the authors estimated.
The research suggested that there has been a growing number of epidemics caused by zoonotic outbreaks and it is challenging to predict the future implications for global health due to limited historical data on the frequency and severity of zoonotic spillover, but it is necessary to take action.
"The ultimate package of measures to support global prevention, preparedness, and resilience is not yet clear. What is clear, however, from the historical trends, is that urgent action is needed to address a large and growing risk to global health," the researchers stated.