25th April 2021
It is understandable to be worried when reading about the discovery of a new virus, especially during a pandemic, but it is important to know that very few animal viruses cause ill health in humans. The discovery of new viruses is happening at an ever-increasing rate, it helps to fill in blanks in our knowledge and improve our understanding.
Just one example is the recent identification by scientists of 140,000 viral species living in the human gut, more than half of which have never been described before and many of which will be beneficial rather than harmful to us. As the old saying goes, ‘seek and you will find’. What is true of humans, is true of other animals. A new virus, from a species of bat, bird, rodent or other animal, often means that a scientist has been looking at species that they have not investigated before or are using new techniques in their work.
Recent research has revealed that bats don’t appear to host any more zoonotic viruses than any other groups of animals (mammals and birds) of similar species diversity (See: Viral zoonotic risk is homogenous among taxonomic orders of mammalian and avian reservoir hosts). The discovery of new viruses in any animal, just as in humans, is expected when scientists start to look. Several ‘SARS like’ coronaviruses have been described in horseshoe bat species. There are more than 100 species of horseshoe bat extending across Europe and Asia, including two in Britain. SARS-CoV-2, the virus that causes COVID-19, has so far never been isolated from a bat.
Zoonotic spillover or zoonosis is the transmission of a pathogen from an animal to a human, often through an intermediary species. For a virus found in an animal to be able to infect humans the pathogen must overcome a series of barriers that otherwise prevent such spillover infections. We know that wildlife trade and habitat destruction along with biodiversity loss can remove many of these barriers and increase the possibility of spillovers happening. A recent article in The British Medical Journal concluded that “Climate and land use change are likely to significantly influence hazards of many zoonoses”. As we have seen with the COVID-19 pandemic, and others that preceded it, if we fail to care for the natural world and all the services that it provides to us then ecosystems can break down in ways that have significant impacts on us, including through emerging infectious diseases.
There have been a small number of cases where non-human mammals have been infected with SARS-CoV-2 following close contact with their owners/handlers, these have included dogs, cats (both domestic pets and big cats in a zoo), mink and otters. To minimise the chances of cross-species transmission, the International Union for Conservation of Nature (IUCN guidelines) has been advocating the use of a precautionary principle in relation to COVID-19 since April 2020. Good hygiene practices are important for anyone who handles wild animals, not just for the person but for the animal’s protection too. We ask anyone who has found a grounded or injured bat, to please cover your nose and mouth when you get near to the bat to contain it. It does not have to be a proper face mask – you can use a tea towel or T-shirt. You must also wear gloves. Please see our advice pages if you find a bat.
We ask that bat workers and bat rehabilitators continue taking extra precautions as per IUCN and government guidance issued in 2020, just as people working with other mammals should, by wearing gloves and a face covering, minimising handling, practicing good hygiene with food and housing, etc.
Bats and diseases
16th June 2021
20th May 2021