All of the national parks in Congo and Rwanda featuring primates have closed their doors to visitors in an effort to avoid Africa's endangered mountain gorillas and chimpanzees from contracting COVID-19.

According to experts, primates are very likely to be sucesptible to the disease, with complications arising from the illness potnetially fatal.

There are just over a thousand mountain gorillas left worldwide, with Africa's oldest national park – Virunga – home to around a third of them. If the virus spread through the population, it could be devastating for the species' survival. As a result, Virunga will remain closed to tourists until at least 1 June.

In Rwana, three national parks have closed to tourists, with research activity also temporarily halted. The Volcanoes, Gishwati-Mukura and Nyungwe parks are now shut, with the Akagera National Park – not home to primates – remaining open.

The closures will have a significant impact on the financial sustainability of these attractions. In Congo, a permit for gorilla tracking and safari costs up to US$400, while in Rwanda the figure reaches US$1,500. In the Volcanoes National Park, an estimated US$19.2m a year comes from Gorilla trekking expeditions.

The World Wildlife Fund (WWF) says it is currently developing ontingency plans to shield parks from sustainability issues, with those plans now starting to be implemented.

"Mountain gorillas are known to be susceptible to other human respiratory illnesses, so we have to assume that they are susceptible to the virus which causes the disease Covid-19 in humans," said a statement form the organisation.

"That means that right now, minimising human-mountain gorilla interaction, and the opportunity for disease transmission, is the priority."