There's a common fear among people that animals like mice can transmit viruses to them. However, the findings suggest that when it comes to spreading viruses, other animals have more reason to fear humans. A recent analysis of virus genomes conducted by scientists at University College London reveals that when viruses spread between humans and other animals, it's more often from humans to animals rather than the other way around. The relevant paper was published in the latest issue of Nature Ecology & Evolution on March 25th.
Some zoo animals have caught COVID-19 from humans.
Source: New Scientist website
Researchers say more viruses are transmitted from humans to animals than vice versa. For instance, after bats transmitted the coronavirus to humans, humans then spread it to many other species.
The team studied virus transmission between species using the Global Sequencing Virus Database. Although the database contains nearly 12 million sequences, many lack information on when they were collected and from which host species. Given this, they selected 60,000 high-quality sequences with complete data and then created a "family tree" of relevant viruses.
The study identified nearly 13,000 virus lineages and 3,000 transmissions between different species. Results show that out of 600 transmissions involving humans, the majority (64%) involved the virus jumping from humans to animals rather than the other way around.
Among these, the three most common viruses transmitted from humans to other animals are the coronavirus, Middle East respiratory syndrome coronavirus, and influenza virus. This aligns with other research, such as humans spreading the coronavirus to pets, zoo animals, farmed minks, and wild deer. Additionally, apart from these three viruses, the remaining 54% were instances of humans spreading the virus to other animals.
The research team warns that humans spreading viruses to other animals poses a threat to many endangered species. For example, outbreaks of human parainfluenza virus and human respiratory syncytial virus have led to the deaths of several wild chimpanzees in Uganda.
