Human disease and our animal cousins


We hear a lot about animal diseases that make the jump to humans—swine flu, for instance. But this transfer goes the other way, too.

There are 786 mountain gorillas left in the wild, and three quarters of those animals are used to being around people. Partially, that's an OK thing. The tourism industry has played a key role in keeping these gorillas protected. On the other hand, though, tourism also means that a small, previously isolated population of primates is regularly being brought into contact with diverse primates from all over the world. It's the perfect set-up for us jet-setting humans to pass on diseases that are completely novel to the gorilla's immune system.

Human metapneumovirus is very common in people, and not terribly dangerous. Most kids have been exposed by the time they're 5. The only people who usually develop complications are elderly, very young, or have compromised immune systems. In gorillas, however, this virus can be deadly. During a 2009 outbreak among one group of gorillas, an adult female and an infant died

This issue is interesting to me, because of the dilemma it poses. As the journal Emerging Infectious Diseases notes: "Human proximity to mountain gorillas is essential for their conservation, also crucial is minimizing the risk for human-to-great ape transmission of respiratory pathogens." How to cover both concerns, at the same time, will be a real dilemma.

Image: Some rights reserved by viralbus


  1. “How to cover both concerns, at the same time, will be a real dilemma.” Why? Is it so hard to warn potential tourists to get their vaccines in order to not carry diseases to the gorillas?

    Well, I’m just saying, maybe we’re talking about diseases so normal to us that you wouldn’t get a doctor to check it…

    1. Nawel,

      It’s not an issue of stuff we vaccinate against. It’s an issue of stuff that hardly matters to us (like Human metapneumovirus) being more dangerous to the gorillas.

      There’s not a vaccine for Human metapneumovirus. There isn’t likely to be one, because something that isn’t usually deadly or damaging to people isn’t a priority for that sort of research.

      So, how do we protect animals against diseases that are so common and low-risk in humans that we don’t even bother to test for them most of the time?

  2. I don’t understand the author’s point. Looking at gorillas from your car or behind a tourist’s telephoto lens is not likely to transmit disease, much less encourage a cross-over mutation (as we saw in the H1N1 swine flu). Hunting gorillas for bush meat WILL expose you to the bodily fluids. In other words, it’s the local tribes that are far more likely to share germs back and forth with the gorillas. The only thing tourists do is provide an economic incentive for the local people not to completely kill off the last wild gorillas.

    Should we be worried about a supervirus from 600 gorillas living in isolated areas? Or should we be far more worried about the billions of pigs raised for meat, many in high-density (factory farm) conditions?

    Did you know that in the US about 2/3rd of the antibiotics used don’t go to help people. They’re used in animals, namely livestock. Most of them are used on a regular basis to encourage weight gain and to keep weak animals alive in high density livestock operations. If we’re worried about creating superbugs and ruining the power of our antibiotics to fight them, we need look only as far as our grocer’s meat case: completely filled with factory farmed animal products.

    1. Funchy,

      Tourists don’t look at mountain gorillas from a telephoto lens or from inside a car. My understanding is that, generally, people are going on hiking expeditions into the bush and seeing these animals at relatively close range. Airborne diseases can be transmitted.

    2. If you read the article, it’s not about catching gorilla diseases, but about them catching human diseases. The virus of concern wouldn’t be from 600 gorillas but from 6 billion humans.

  3. There are 786 mountain gorillas left in the wild

    Sorry to get hung up on this statistic, but it’s just such a heartbreakingly small number.

  4. Maggie,

    As a current great ape researcher and diligent Boingboing reader I feel compelled to respond to a few comments made here. Eco-tourism (or ape-related tourism specifically) has not necessarily been regarded by most researchers and conservationists as a beneficial method of promoting conservation. Most ecotourist programs, including the programs involving gorillas in Rwanda, allow small parties of tourists willing to pay steep prices to view the gorillas at a relatively close distance. Researchers interested in working with wild apes encounter the same problem as those monitoring ecotourist groups, in that they must be wary of disease transmission.

    At the site where I work (wild chimpanzees), we aim to maintain a minimum distance between researcher and ape so as to limit the potential for disease transmission. Ecotourist groups generally do this as well, although visitors to those apes do not undergo as stringent requirements for vaccinations. Folks who work with apes, both captive and wild are required to be vaccinated for a multitude of disease, and tested often (expensive!) for diseases like TB. Additionally, many of the sicknesses us humans carry are harmful to apes (even the common human cold can be fatal) and do not have vaccinations. For better or worse, it would be costly and detrimental to the success of ecotourist programs to require visitors to adhere to similar requirements. Therefore, this specific brand of ecotourism is in a sense a catch 22 in that it promotes the conservation of ape species while exposing these species to additional anthropogenic threats.

    To address funchy specifically, the habitat in which tourists view the gorillas does is not conducive to the use of cars (mountainous), and small groups are able to come within close viewing distance of the gorillas. In addition, as humans and other non-human primates are so closely related, especially apes, there is great reason to be concerned about disease transmission between apes. Diseases do not necessarily need to mutate in order to be able to affect more than one species, and many which are of concern to researchers and conservationists alike do so quite handily.

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