Professor Sarah Gilbert, the senior scientist working on the University of Oxford’s coronavirus vaccine project, has warned that even after a solution is found to address Covid-19, additional similar diseases are likely to emerge in the future.
Speaking to The Independent, Gilbert cited “greater population density, greater travel, deforestation” as the likely causes of new zoonotic infections. Zoonotic illnesses are those that are first detected in animals and later spread to humans, as is believed to have happened with the novel coronavirus. Scientists believe that Covid-19 originated in bats, consumed as a matter of course in many Far Eastern countries and on sale (dead or alive) at Chinese “wet markets” such as that in Wuhan, China, where the coronavirus is thought to have originated.
Other recent zoonotic diseases that have caused deadly illness in humans have included Ebola (from fruit bats), Sars (of as yet undetermined origin, but believed to be from civet cats), and West Nile Virus (from birds, to humans via mosquitoes).
Zoonotics are nothing new. Evolutionary scientists point to animals as the sources for diseases now thought of as uniquely human, such as measles and influenza. According to their theories, measles developed from rinderpest (cattle plague) around a thousand years ago – or, alternatively, from a virus that originally affected dogs and mutated over the generations until it became the virus that we know today. Influenza may have originally been a bird disease until it made its fatal jump to humans via fowl.
Even salmonella, associated in the minds of most with raw eggs and other contaminated food, often originates from reptiles such as turtles, frogs, or snakes, kept as household pets.