Colds spread quickly between gorillas when they are around each other

We’ve all had to get used to the term “social distancing” over the past 18 months.

But it turns out that it’s not just humans who need to conserve their space to ward off the risk of disease.

Coughs and colds also spread quickly between mountain gorillas when they are in close proximity to each other, according to a new study.

Researchers have found that respiratory infections are much more likely to spread among groups of wild monkeys than between neighboring groups.

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Because humans and gorillas are so closely linked, our ape cousins ​​can catch many of the same diseases we do.

However, relatively mild infections in humans can have major consequences for gorillas and chimpanzees, where a case of the common cold or flu can be fatal.

This is why this study is important because it sought to understand how diseases are transmitted by groups in order to help shape future conservation strategies.

It was carried out by scientists from the Dian Fossey Gorilla Fund in the Volcanoes National Park, Rwanda.

They studied 15 respiratory epidemics over the past 17 years to understand how infections spread through a population of mountain gorillas.

“If we can better understand how diseases have spread in the past, we will be able to better prepare for and respond to epidemics in the future,” said Dr. Robin Morrison, lead author of the study.

Researchers found that close contact and strong social relationships within gorilla groups allowed respiratory illnesses to spread rapidly between monkeys.

What they couldn’t predict, however, were a group’s social network transmission patterns. In one of the outbreaks, it took just three days for 45 of the 46 members of the group to start coughing.

This differed from the results of an earlier study, in which the wider social organization of chimpanzees led to slower overall transmission.

The researchers were also able to predict the spread of the disease based on the chimpanzee’s social network – for example, those at the center of the network were more likely to display clinical signs than those with fewer connections.

The good news for the endangered gorilla population in this latest study is that researchers found there were limited opportunities for infections to spread between neighboring groups.

“The epidemics we investigated all seemed to stay within a single group rather than spreading through the larger population,” said Yvonne Mushimiyimana, co-author of the project.

“Groups of gorillas interact quite rarely, and when they do, they tend to keep their distance, rarely approaching that crucial 1 to 2 meter distance.”

This distance from neighboring groups may actually help protect the wider population by limiting the wider transmission of these infections, experts said.

However, this raised the question of where the outbreaks came from if neighboring gorilla groups did not become infected.

Previous studies in wild monkeys have put the blame on human pathogens.

One example is in Uganda, where two neighboring chimpanzee communities started showing signs of respiratory infection at the same time, only for genetic analysis to reveal that the infections were caused by two entirely separate human pathogens.

This came as a surprise to scientists, but showed that the two infections were transmitted independently by humans rather than spreading between two communities of chimpanzees.

“Our best guess is that these infections in mountain gorillas come from humans,” Morrison said.

“This really underscores the importance of continued efforts to minimize exposure of wild great apes to human disease during activities such as research, tourism and protection.

“Vaccination, wearing a mask and maintaining a proper distance are all more important than ever in the midst of a global pandemic.”

The aim of the research is to identify strategies to limit the spread of the disease. The researchers hope their study will help understand how transmission might work in different gorilla populations.

“The results of this study suggest that, since respiratory diseases are transmitted rapidly within gorilla groups and transmission between groups is much less common, strategies that prevent initial transmission in a group may be the most common. effective, “said Dr Tara Stoinski, President and Scientific Director of the Fossey Fund.

“For Covid-19 and other human respiratory pathogens, this means preventing this first introduction of disease from a human to a gorilla.”

She added: “Although the research was completed long before the onset of Covid-19, the current pandemic highlights the fact that it is more vital than ever to minimize the pathways of disease transmission between humans. and monkeys, which pose a risk to wild great apes and humans alike.

The research is published in the journal Scientific Reports.