Why shouldn’t you get close to great apes?
AHumans and great apes are so genetically similar that these animals are at risk of catching diseases from us – to which they have no immunity. A study published in 2018 identified 33 known instances in which people had transmitted pathogens to chimpanzees, orangutans and gorillas, in captive, semi-wild and wild populations.
Diseases that can be passed onto great apes include respiratory conditions such as influenza, pneumonia and tuberculosis, and bacterial infections such as salmonella.
But even a seemingly unthreatening virus can have a devastating impact. In 2009, for example, 11 out of 12 mountain gorillas in Rwanda became sick after contracting the human metapneumovirus (which, for us, manifests as a common cold); of these, an adult female and an infant male died.
This is why mountain gorilla tourism rules specify that you should not approach closer than 7m if you’re wearing a mask; 10m if you’re not, and why time with any group is limited to just one hour.
Getting too close to gorillas probably poses more danger to them than it does to you.