It will probably not be chosen as Word of the Year, but many will have read it for the first time this year: zoonosis. Media trying to explain in February what the new coronavirus actually is often started with: ‘The new coronavirus is a zoonosis’. In other words: an infectious disease that can be transmitted from animals to humans. Sometimes this involves animals that we know well, such as goats and sheep (Q fever) or chickens and turkeys (bird flu). In this case, exotic animals like bats and pangolins are often mentioned as sources of COVID-19. Mention exotic animals, and AAP is on the alert, so we delved into the archives to find out which zoonoses can occur among exotic animals that can be kept as pets in Europe. And what the consequences are in case of an outbreak.
In the report ‘Under their skin’ we zoom in on a number of common zoonoses. Did you know that 3 out of 4 zoonoses originate from primates, bats or rodents? All animals we take in at AAP. Researchers estimate that about 1.6 million pathogens (virus species) and their effects on humans are not yet mapped. Some 650,000 to 840,000 variants could be harmful or even deadly to humans. What is becoming particularly clear: we still know very little about what lurks under the skin of animals.
Much remains unknown All the more risky is the fact that the number of exotic animal species in European living rooms has continued to grow rapidly for decades. In the Netherlands alone, more than 300 different species of mammals are kept as pets or hobby animals. How many animals this involves and who keeps them we do not know; in virtually no European country is this registered. It is also not clear which zoonoses can be transmitted by which animals. A number of practical examples give an idea but it is by no means complete. To get a better picture, medical checks on exotic pets would be necessary, but these are not mandatory anywhere. This is in contrast to domesticated pets and livestock, about which much more is known.
Fatal examples One of the zoonoses that can lurk in exotic pets, for example, is Q fever (coxiellosis). This disease, from which 74 people in the Netherlands died between 2007 and 2011, is not only found among goats. Dogs, cats, coyotes, foxes, jaguars, rodents, skunks, raccoons, rabbits, sloths and birds can also transmit it. And indeed; many of these species may be kept as pets in the EU. Or the hard-to-identify tularemia (also known as hare fever or rabbit fever), which can also be fatal to humans. Known sources of this are lemmings, hares, rabbits, water rats, grassland voles and some rats and squirrels. We could go on like this for a while. Mycobacterium bovis, also called bovine tuberculosis, is spread by numerous farm animals plus badgers, deer, boars, lions, elephants, meerkats and possums. Last but not least, salmonella – also a zoonosis. It is estimated that about 3 million people die each year from infection – transmitted in 3-5% of cases by exotic pets. Often via reptiles like iguanas and turtles, sometimes by mammals like the popular sugar gliders (sugar squirrels) and hedgehogs.
Chance x Consequence = Risk So far, no major outbreak can be linked to the keeping of exotic pets, but the risk is obvious. Three German hobby keepers who contracted bornavirus 1 (VSBV-1) from a pair of large spotted tree squirrels in 2015did not survive. How many more borna and corona viruses are waiting for us? No one knows.
Four of the five zoonoses listed here are classified by RIVM in the highest risk category for humans (EMZO risk IV, RIVM 2010). How much risk are we willing to accept for a hobby? The chance that COVID-20 will spread to a human in a Dutch living room seems small. But should it happen, the impact could be gigantic. What is it worth to society to eliminate that risk?
Positive list AAP is and remains in favor of a positive list for mammals that are safe to keep. Currently a new domestic and hobby animal list is being developed and the risk of transmissible zoonoses is also considered in the assessment of whether an animal species is suitable. We think this is an absolutely crucial and essential criterion. In the interest of animals, but also of public health, this list cannot come soon enough
