Image copyright Getty Images Image caption It's not known how the virus might affect great apes like gorillas

Conservation experts are calling for urgent action to protect our closest living relatives, the great apes, from the threat of coronavirus.

New measures are needed to reduce the risk of wild gorillas, chimps and orangutans encountering the virus, scientists warn in a letter in Nature.

Habitat loss and poaching are big threats to the survival of great apes, but viruses are also a concern.

Scientists say the current outbreak warrants the utmost caution.

Infectious disease is now listed among the top three threats to some great ape groups.

"We do not know what the effect of the virus on them is and that means we have to take the precautionary principle and reduce the risk that they will get the virus," said Prof Serge Wich of Liverpool John Moores University, UK, who is a co-signatory of the letter.

"That means halting tourism, which is happening in several countries already, reducing research, being very cautious with reintroduction programmes, but also potentially halting infrastructure and extractive projects in great ape habitats which bring people in closer contact with great apes and thus potentially spread this virus to them."

Image copyright Getty Images Image caption Orangutans are rapidly going extinct

While many viruses, bacteria and parasites circulate in great apes without causing harm, some are known to cause disease.

Past research has shown that chimps can contract the common cold virus, while the Ebola virus is thought to have killed thousands of chimpanzees and gorillas in Africa.

Prof Wich said a detailed assessment was needed of all projects in great ape habitats to evaluate what the risks are.

"For species with low numbers such as the Tapanuli orangutan, a virus spread could potentially bring them even closer to extinction," he said.

The Tapanuli orangutan is a species of orangutan restricted to one part of the island of Sumatra in Indonesia.

Fewer than 800 individuals are left in the wild. Prof Wich was one of the scientists who confirmed this was a distinct species of orangutan in 2017.

There are four types of great apes alive today: gorillas (Africa), bonobos (Africa), orangutans (SE Asia), and chimpanzees (Africa).

Humans are closely related to great apes, sharing a common ancestor several million years ago.

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