No, for the uninitiated, the title doesn’t refer to some kind of sexual euphemism. From the Bushmeat Task Force:

In Africa, forest is often referred to as ‘the bush’, thus wildlife and the meat derived from it is referred to as ‘bushmeat’. This term applies to all wildlife species, including threatened and endangered, used for meat including: elephant; gorilla; chimpanzee and other primates; forest antelope (duikers); crocodile; porcupine; bush pig; cane rat; pangolin; monitor lizard; guinea fowl; etc.

Some of this can be hunted legally–much of it is not. Though I won’t be concentrating on the bushmeat crisis per se (the focus of the Bushmeat Task Force), they note several ways it is obtained:

BCTF is most concerned with bushmeat that is illegally, commercially and/or unsustainably derived from wildlife, including that characterized by illegal methods of hunting (wire snares, unregistered guns); illegal species (endangered, threatened, or protected); taken from unauthorized areas; and unsustainable offtake for commercial trade or non-commercial uses.

While their concern lies largely in the treat to wildlife caused by this kind of illegal hunting (a valid concern, especially where non-human primates and other endangered species are concerned), the focus of this post will be the danger this type of food source poses to humans.

I’ve already discussed in part 1 and part 2 of the series some ways that microbes can jump from animal to human, and some factors which affect the emergence of these types of diseases. Though I didn’t specifically mention bushmeat consumption, this is another factor in Africa with the potential to have a huge impact on introduction of new diseases into the human population.

Bushmeat is often a part of the diet of rural African communities. In some areas of Central Africa, bushmeat comprises up to 80% of all animal-based protein. In this area, duikers (forest antelope; pictured above is a red-flanked duiker) are the most common type of bushmeat, but if they begin to dwindle, hunters may shift to other animals–including primates.

Killing and eating primates is known to have introduced disease into human populations in Africa in recent years. For example, an Ebola outbreak in 1996 in Gabon began when patients became ill after butchering and eating a dead chimpanzee that they had found. Additionally, evidence of simian immunodeficiency virus (SIV) infection has been reported for at least 26 different species of African primates, many of which are regularly hunted and sold as bushmeat. Though there have been rumors that SIV spread to humans via sexual contact between the two species, it’s much more likely that the movement occurred due to butchering and/or consumption of infected primates. Indeed, to go back to Ebola, another case of that virus resulted in 1994 on Africa’s Ivory Coast after a researcher had performed an autopsy of a dead chimpanzee, and likely cut herself by accident during the procedure. Other animals can introduce disease as well–for example, monkeypox from a variety of rodent reservoirs which may be eaten, trichenella from wild boar, etc. Almost any animal species can be a source of a novel disease, and this zoonotic transfer due to bushmeat consumption is probably more common than we realize.

Unfortunately, trade in bushmeat is not expected to decrease anytime soon. Logging and mining operations have opened up new areas of forest to commercial hunting, increasing the risk that humans in Africa will be exposed to new diseases via the bushmeat they consume. Obviously, one also simply can’t expect impoverished people in this continent to stop consuming the meat that makes up much of their diet–bushmeat is unlikely to be replaced unless cheaper substitutes are available, which don’t appear to be on the horizon. What can be done is to educate people on how to more safely butcher and consume this type of meat, and as a long-term goal, to improve the public health infrastructures of countries in the region in order to better identify and manage outbreaks that occur (whether they’re due to bushmeat consumption or other causes). This won’t be easy–even our own public health infrastructure is lacking, and educational campaigns must be carried out in manners which understand and respect cultural differences.

Finally, in addition to being a source of protein, hunting bushmeat is a fairly lucrative occupation in these impoverished areas. This results in the distribution of more than a million tons of bushmeat each year in the Congo basin alone. A bushmeat hunter can earn $300-1000 a year (more than the average income of the region), and the total value of the bushmeat trade in Africa is estimated at ~$50 million (US dollars) annually accurding to this site, while this publication by the OIE puts the figure for all international bushmeat trade at $1 billion US. Bushmeat hunting can also be compounded by war, which I’ll discuss further tomorrow. This is a huge problem, and unfortunately, one likely to only grow in the immediate future.

For more information:

The Jane Goodall Institute
The bushmeat crisis task force
The bushmeat project
Image from http://www.berkeley.edu/news/media/releases/2004/11/images/Bushmeat-Duiker.jpg

Comments

  1. #1 Urinated State of America
    March 29, 2006

    Not quite on topic, but I wonder Tara if you could comment on the Black-Death epidemic in the 14th Century caused by Tartars during the siege of Kaffa lobbing plague-infected corpses over the walls.

    It’s always seemed a bit of an urban myth to me (a non-epidemiologist), as (1) fleas would be expected to have left the corpses (2) the primary transmission route for plague (in the pnuemonic form) is person to person, and that the catapulting the corpses, while horrific, wasn’t the route for plague entering the city of Kaffa.

    What’s your opinion?

  2. #2 Dave S.
    March 29, 2006

    USA –

    I think you’re right that the flinging corpses, while a gruesome thing, probably did not do much to spread The Plague in Kaffa. More likely what happened was that live rats carrying the fleas penetrated the town walls from the besieging encampments and it spread that way. Something similar apparently happened later on when Gloucester tried the same tactic.

  3. #3 natural cynic
    March 29, 2006

    Hmmm, Bushmeat. I would gladly risk emesis for a well braised chunk of his well-toned ass. There aren’s enough brains to fight over, though.

  4. #4 Urinated State of America
    March 29, 2006

    “More likely what happened was that live rats carrying the fleas penetrated the town walls from the besieging encampments and it spread that way.”

    I was thinking it more likely that the (pneumonic) plague spread via person-to-person route. IIRC, rats don’t move around sufficiently to be a vector for an infection spreading that rapidly.

  5. #5 Cayte
    March 29, 2006

    IMO, besides finding out why new pathogens are emerging we need to do more to find out why they are going virulent. Clearly if bird flow were an ordinary garden variety flu its emergence wouldn’t be front page news. Molecular tweezers can’t be relied on to solve an ecological problem.

    Ewald has done work on this issue. I’m reading “the Art of Being a Parasite” by Combes. These sources are not the last word but they seem to be the first words in a discussion that should be ongoing.

  6. #6 Paul
    March 30, 2006

    Your post, and the very term ‘bushmeat’ seem to connote Africa, and you seem to suggest that we find alternatives for Africans currently eating bushmeat.

    But why Africa? Does the same risk apply to deer and moose hunters in North America? Or anyone who eats animal protein from farmed animals? I would guess that primates would be more likely to carry microbes adapted to the conditions inside the human body, but how is a duiker different from a deer, or even a cow? Why do you say that African bushmeat is a more dangerous source of microbes?

  7. #7 Dave S.
    March 30, 2006

    Paul says:

    Your post, and the very term ‘bushmeat’ seem to connote Africa, and you seem to suggest that we find alternatives for Africans currently eating bushmeat.

    But why Africa? Does the same risk apply to deer and moose hunters in North America? Or anyone who eats animal protein from farmed animals? I would guess that primates would be more likely to carry microbes adapted to the conditions inside the human body, but how is a duiker different from a deer, or even a cow? Why do you say that African bushmeat is a more dangerous source of microbes?

    In the opening post, Tara mentions that, “In some areas of Central Africa, bushmeat comprises up to 80% of all animal-based protein.” In addition, there is concern over the sheer variety of fauna used in this fashion. In the west, consumption of game meat is far less than this, and is far more stringently regulated. You don’t see for instance see the “…commercial exploitation of endangered and threatened species used as food.” (see link) as you would in Africa. The possible arguable exception here might be the native peoples.

    In farm animals, there are more regulations and health checks still. Not that this is any guarantee mind you. One still might see some sort of disease transference in the West, but the larger scale and scope in Africa, coupled with the fact there are no primates hunted for food in the West (aside from the very rare and possibly apocryphal cannibal cases), suggests Africa is at greater risk.

    I would also mention the term “bush meat” or “bush tucker” is used in Australia as well.

  8. #8 Tara C. Smith
    March 30, 2006

    Dave touched on a lot of it. I’d just add that in many African countries, public health is nil, so diseases can spread significantly before an outbreak is detected. And the contact with and consumption of non-human primates is also more frequent than anywhere else in the world. Obviously microbes can jump between even distantly-related animal species, but our close kinship with these primates makes it an especially worrisome situation.

    Certainly farm animals and other wild animals such as deer and elk can be a risk as well–here in the US, there is a lot of concern over chronic wasting disease in these populations and its possible transmission to humans via contaminated meat, for instance. And sure, farmed meat can be a disease vehicle as well, but at least we have inspectors that work to control that (obviously, not perfectly, but it’s a start). But we simply don’t have as large a population eating–and butchering–wild animals as they do in Africa. That’s ground zero, you might say, while other areas are of lesser risk.

  9. #9 dale
    March 30, 2006

    I expect a lot of the game meat that is consumed in North America is also cooked a lot more thoroughly than that consumed in Africa.

  10. #10 Andrew Staroscik
    March 30, 2006

    Dale,

    In my experience (Peace Corps Gabon in the early 90′s), they cook the heck out of the bushmeat, the more rotten the meat (and most of it is quite ripe by the time it is cooked), the more they cook it.

    The problem is a lack of understanding of basic sanitation. Hands, utensils and surfaces are not cleaned well or disinfected after handling the meat and it is prepared and cooked in the same area where things such as fruit and vegetables that will be eaten raw are kept.