Why can gorillas be infected with the coronavirus?

Three gorillas have tested positive for coronavirus at a San Diego zoo. They have a light cough but should make a good recovery. This species is genetically very close to humans.

At the San Diego Zoo, gorillas were tested positive SARS-CoV-2 coronavirus. Two of them started coughing on Wednesday, January 6, 2021, which is not so common, so in the context, the symptom quickly set off a screening process – different from that of humans, so no impact on PCR testing capabilities. As a result, three gorillas at the zoo have been confirmed to have Covid-19 disease.

« Aside from a little nasal congestion and cough, gorillas are doing fine. », Specified in a communicated zoo director Lisa Peterson adding that all eight gorillas in the enclosure have been placed in isolation. A ” full recovery Is to be expected, since they have not developed a severe form of the disease. As for the infection process, the zoo normally applies a strict sanitary protocol in human-animal contact, but the gorillas presumably caught the coronavirus through a staff member being asymptomatic.

This is the first time that the coronavirus has been detected in gorillas. Previously, mink, tigers, lions and some cats and dogs were in the same situation. The SARS-CoV-2 coronavirus is adapted to humans, which is why contamination of another mammal susceptible to infection does not generate worrying forms of the disease: the coronavirus can hardly thrive in an organism in which it is is not suitable – except for mutation, which is why the case of mink was problematic. The domestic animals cannot be vectors of the epidemic, nor be really in danger.

The danger is however somewhat different for a species like gorillas.

Primates are at risk

A study published in August 2020 in the review PNAS examines potential hosts for the SARS-CoV-2 coronavirus among vertebrates. The authors looked at 400 species, through the prism of ACE2 receptor proteins. The more a species sees its ACE2 receptors similar to humans, the more the coronavirus represents an infectious danger for it, because the binding between its Spike protein and these ACE2 receptor proteins is facilitated.

Among the species most at risk, there are three families of catarhines, a clade of primates: cercopithecidae, hylobatidae, and hominidae. Catarhines are the mammals classified in the study as the most endangered category in the pandemic: ” the risk of infection with SARS-CoV-2 is very high “. Gorillas belong to the hominid family, like humans. Genetic proximity is strong; the risk of contagion is therefore high.

Remember that gorillas are one of the critically endangered species in the face of declining populations. In their study published in PNAS, the authors point out that they have identified many endangered species among those most at risk in the epidemic: ” It is important to note that many threatened and endangered species are potentially at risk of infection with SARS-CoV-2, based on their ACE2 binding score, which suggests that as as the pandemic spreads, humans could inadvertently introduce a new, potentially devastating threat to these already vulnerable populations, especially great apes and other primates. »

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