Archives for posts with tag: African history

A Harvard researcher who tracks Ebola’s evolution remembers being “totally shocked” when he learned that Zaire ebolavirus was behind reports of a mysterious hemorrhagic fever cropping up in Sierra Leone last January. Lassa fever or even the rare Côte d’Ivoire Taï Forest strain of Ebola would have been more logical pathogens according to him, and the question remains:  how exactly did the most lethal form of Ebola – which was previously restricted to Central Africa – suddenly appear thousands of miles away on the edge of West Africa? Researchers may never be able to provide a precise explanation, but they have developed several theories as to how Zaire ebolavirus “jumped” across the continent.

Some background on the basic evolutionary biology of Ebola is necessary to appreciate the mystery presented by this mammoth leap. Moving down the tree of evolutionary similarity, the Filoviridae family encompasses the Ebolavirus genus, of which there are five distinct (known) species: Zaire ebolavirus, Sudan ebolavirus, Reston ebolavirus, Bundibugyo ebolavirus, and Taï Forest ebolavirus. All are found in Africa except for Reston, which has only appeared in a Virginia lab.

Despite widespread reports that the current Ebola outbreak is West Africa’s first instance of the virus, one previous case of Ebola was recorded in the region prior to last December. The case occurred when a female Swiss ethologist contracted the disease while conducting a necropsy on an infected Chimpanzee in the Taï Forest region of Côte d’Ivoire that borders Liberia. She survived what virologists eventually determined to be a separate species of Ebola, and this year’s outbreak in Liberia, Guinea, and Sierra Leone surprisingly has no connection to that species now known as Taï Forest ebolavirus.

The culprit of this year’s outbreak, Zaire ebolavirus has likely circulated in the forests of Central Africa for hundreds of years. The first confirmed case occurred only in 1976 near the Ebola River in Zaire, but based on the virus’s mutation rate, Ebola likely split from Marburg virus – another deadly member of the Filoviridae family – around 800 years ago. Further evidence for the long history of Ebola in Central Africa comes from the virus’s presence in stored samples collected from Gabon primates prior to 1976. Previous cases likely went internationally undetected in part because of long practiced indigenous protocols such as isolating infected people outside of villages in addition to community-wide dietary restrictions during times of unusually severe afflictions (see Matthew Barry’s anthropological research on Ebola).

After 1976, Zaire ebolavirus went eerily quiet but reemerged again in the mid-1990s, beginning a series of semi-annual outbursts that continue to this day in Central Africa (the recent 2014 DRC outbreak is the latest instance and is unconnected to the West Africa outbreak). Contrary to many recent news reports, these sporadic episodes have affected bustling cities (Gulu, Kikwit) and have spread via air travel (from Gabon to South Africa), but the initial index cases have always originated in Central Africa, and the outbreaks have never eclipsed more than a few hundred cases.

The 2014 West African outbreak broke this pattern. Scientists have now traced its origin back to a two year old boy who was likely exposed to fruit bats last December in Guinea, ruling out an immediate cause of an infected person bringing the virus directly from Central Africa.

The connection of fruit bats to an Ebola outbreak is not unusual, and bats have been linked to several other index cases over the years. As a result, bats are the leading suspect for the elusive and long sought “reservoir” animal that asymptomatically harbors the virus between human outbreaks. Tests on thousands of animals in Central Africa have yet to find definitive traces of ebolavirus, perhaps because the virus is also rare amongst animals or else only flares up for short spells.

Even within a single species of Ebola, the virus’s DNA constantly mutates each time it jumps from animal to animal, or animal to human. Thankfully the mutation rate for Ebola is much lower than other RNA viruses such as HIV/AIDS, providing more hope for a sustainable cure. Based on its slow rate of mutation, the genetic structure of the Zaire strain ravishing West Africa seems to have separated from its Central African parent strain of Zaire ebolavirus about a decade ago.

This estimate gives scientists about a ten-year window within which to speculate as to how Zaire ebolavirus ended up in West Africa. Here again, bats present the most likely link.

One theory picked up by those with a taste for primitiving Africa, postulates that Africans’ supposed appetite for bat meat (and bush meat in general) has led to the illegal smuggling of infected bats or chimpanzees from Central Africa to West Africa. While it is true that infected primates acted as vectors for bringing Reston ebolavirus to the US and Marburg virus to Germany, there is no evidence of an elaborate black market for bush meat criss-crossing Africa. Assuming a thriving bush meat trade is to misunderstand the driving factor behind wild game consumption in Africa: poverty. West Africans don’t import chimpanzees and bats from Central Africa as exotic delicacies—hungry villagers hunt small game in the forest to add protein to their diets, as other forms of meat are often prohibitively expensive. The average annual income in Guinea is $416 (World Bank).

A more likely scenario for Ebola’s jump involves the long distance migration of bats. Bats are unique amongst mammals in their ability to fly, and recent research tracking their flight patterns has uncovered that they often travel hundreds of miles a year in search of insects. Just about everything about bats from their migration routes to their immune systems is notoriously understudied.

According to the few published studies, scientists know that there are “metapopulations” of bats – separate colonies (whose members can run into the millions) that interact on some level. In other words, large populations of bats come into contact with other large populations of bats at the fringes of their territories or as they migrate, allowing pathogens to pass between them. Along such a metapopulation network, Zaire ebolavirus could have worked its way up the coast of West Africa. Preliminary positive tests for Zaire ebolavirus in bats found in Ghana – about halfway between the DRC and Guinea – support this theory of a gradual passing on of Ebola.

One factor that complicates this picture of bat-born Ebola is the fact that human outbreaks seem to only occur in regions of Africa where large primates are found. This remains a puzzling mystery, but one possible explanation floated is that Ebola needs to be – in a sense – shaken back and forth between bats and non-human primates before it mutates into a form that can be picked up by humans. An intriguing theory and time will tell if index cases eventually do emerge from areas without non-human primates.

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Although 1976 marked the first discovery of Ebola by international scientists, the virus likely has a much deeper history lurking in Central Africa. By testing stored blood samples of 790 chimps and gorillas from Cameroon, Republic of Congo, and Gabon, scientists determined that primates had acquired Ebola prior to known human outbreaks in the areas where the samples were originally taken.[1] Subsequent blood samples of people living in Central Africa have shown that as much as 32.4% of the population possess Ebola antibodies (igGs), which they likely developed from exposure to fruit contaminated by bat saliva containing inactive strands of the virus.[1B] These findings have led the researchers to conclude that the virus has long circulated in the vast forests of Central Africa, infecting human and nonhuman primates.

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Chimpanzee in tree, Kabale National Park, Uganda (Mark Duerksen, 2011)

Further evidence of a lengthy history of Ebola outbreaks comes from recent calculations based on the mutation rates of Ebola and Marburg viruses (unusually slow for RNA viruses) that show that the two filoviruses diverged from a single common source around 700 to 850 years ago—around the time when larger and more centralized Bantu speaking societies began to emerge in Central Africa.[2] Given this timeframe for Ebola’s emergence, it is highly improbable that isolated human cases of Ebola did not occur at least occasionally for several centuries before 1976. [Of course humans could have contracted other older forms of Filoviruses long before this timeline, and there has been speculation that ancient plagues such the one that struck Athens in 430 BCE were actually caused by Ebola-like filoviruses.[3]]

The reason why international scientists were unaware of the Ebola’s existence prior to 1976 may be in part explained by the research of Barry Hewlett, a medical anthropologist from Washington State University and a member of WHO’s Ebola response teams. Hewlett’s socio-cultural findings suggest that the people of Northern Uganda and Congo have developed effective methods for containing epidemic diseases such as Ebola. When the Acholi people realized that they were dealing with a more serious affliction (gemo instead of yat) during the 2000 Ebola outbreak in Gulu—Northern Uganda’s largest city—they implemented a protocol that prevented an even larger outbreak. This protocol included isolating victims in huts at least 100m from other homes, encouraging everyone to limit their movement, allowing only survivors of the illness (or, if not possible, an elderly person) to treat and bury the victims, and only eating meat freshly butchered from cattle. While the Acholi incorporated modern medicine into their local beliefs and treatments throughout the outbreak, the elders were adamant that the gemo protocol existed before the late nineteenth century arrival of Europeans. Their assertion has yet to be historically verified, but the specificity of the regiment and the degree to which it is enmeshed in the language and religious belief system of Acholi people suggest that they developed the emergency procedures over numerous generations in response to outbreaks of Ebola or other similar diseases.[4] Indigenous medical measures such as the Acholi’s may explain why prior to 1976 Ebola failed to erupt into outbreaks large enough to attract international attention.

[1] E. M. Leroy et al., “A Serological Survey of Ebola Virus Infection in Central African Nonhuman Primates,” Journal of Infectious Diseases, 190(2004), 1895-1899. Online: http://www.ncbi.nlm.nih.gov/pubmed/15529251

[1B] Dieudonne Nkoghe et al, “Risk Factors for Zaire ebolavirus—Specific IgG in Rural Gabonese Popultions,” The Journal of Infectious Diseases 204(2011), S768-S775.

[2] A. S. Carroll et. al., “Molecular Evolution of Viruses of the Family Filoviridae Based on 97 Whole-Genome Sequences,” Journal of Virology, 87(2013), 2608-2616. Online: http://www.ncbi.nlm.nih.gov/pubmed/23255795

[3] Constance Holden, “Ebola: An Ancient history of a “new” disease?” Science 272(1996), 5268. Online: http://search.proquest.com.ezp-prod1.hul.harvard.edu/docview/213553956/79244C745EFA4C4DPQ/2?accountid=11311

[4] Barry S. Hewlett and Bonnie L. Hewlett, Ebola, Culture and Politics: The Anthropology of an Emerging Disease, Belmont, CA: Thomson Wadsworth, 2008.

It’s been a while since I’ve had a chance to post, but seeing a sneak peak screening of Half of a Yellow Sun tonight has moved me to type up a few thoughts. First of all it was a terrific movie–maybe the best big budget film that I’ve seen set in Africa (and I don’t dislike movies like Blood Diamond and The Last King of Scotland). Warning: it starts slow. I hope critics sit through the whole thing and don’t write it off based on the first twenty minutes where we feel like the director and actors are getting their bearings. It was actually shot in Calabar and Town Creek, Nigeria by a Nigerian director (Biyi Bandele) and with a Nigerian production company, so I imagine a learning curve was a factor. Biyi Bandele started as a playwright and in the beginning the film feels more like a videotaped play that doesn’t quite match the periodicity of the historic footage of 1960s Nigeria that’s mixed in throughout the film to narrative the numerous political turns the country took during that rocky first decade. So, not having read the book, I started to worry that the movie was flopping about 30 minutes in when it was basically a historic soap opera that followed the lives of twins (Olanna and Kainene) in the first few years of independence as they moved from Lagos to Nsukka and Port Harcourt, fell in love and lost their trust in their lovers. Sex, jealousy, and lover’s rows summarize the first half of the film, shot in intimate frames that offer slivers into the lives of the characters. The second half of the movie pans out cinematographically and in content when war breaks out in a shocking scene at an airport. Despite the choppiness out of the gate, by this point we really know the characters through all their tribulations and more comedic moments (which there are plenty), and how many movies about Africa can we say that about before the violence breaks out?? Then the second half of the film left my heart in my throat. The war, the suffering, the constant anxiety of the second act hints that the first act’s over-the-top-soap-opera-style may have been self-conscious satire. The most memorable line in the movie comes as Olanna and Kainene are walking down a dirt road after they’ve each lost all security due to the atrocious war, and Kainene says, “There are some things that are so unforgivable that they make other things easily forgivable.” I’m kind of spelling it out here, but based on the early Rotten Tomatoes reviews (mostly from Australians where it’s already been released who have said things like “Much of the narrative plays out like a TV melodrama;” “Only when the protagonists’ lives are at stake – and bombs drop – does the piece truly come alive, with a sense of much-needed urgency;” “Bandele fails to establish the narrative’s wider national and political context, and the film is ultimately insubstantial as a result.”), I’m concerned that critics will miss the message of the movie along with why Bandele chose to partition it the way that he did. If this continues to be the critic’s take, don’t buy it; see Half a Yellow Sun for yourself and see past the production hiccups and the unfamiliar pacing to experience a stunning adaption about love, loss, and Africa. Oh yeah, I almost forgot to mention that the one white character is very much in the periphery even if his presence helps American audiences digest and relate to the movie. Refreshing.

Here’s the Trailer for those who haven’t see it yet.

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Here’s a summary I wrote of Stephan F. Miescher’s article, “Building the City of the Future: Visions and Experiences of Modernity in Ghana’s Akosombo Township,” which appeared in the November 2012 issue of the Journal of African History:

In his article, Miescher details the history of the Akosombo Township that the Nkrumah’s government commissioned in the early 1960s to house the workers for the accompanying Akosombo hydroelectric dam. He compares the high modernist visions for the Akosombo township (that Greek Urbanist Constaninos Doxiadis designed) versus the reality that lived out over the years as local workers and their families moved in and brought their own knowledge and lifestyles. The dam and Nkrumah’s modernist agenda has attracted past scholarship, but the visions and experiences of the township’s residents have been ignored. Almost immediately the resident’s modes of living clashed with the official plans as rural workers brought families and animals with them into the city planned for single industrial labors. A makeshift “shadow city” known as the “Combine” sprang up as they tend to in planned modern cities in developing nations (Brasilia), resulting in contention between its inhabitants and the VRA (Volta River Authority) who wished to level it to preserve the model city. Eventually the Combiners were relocated (with the support of the national government) and provided with a slab of concrete and building materials to construct approved housing in an orderly, new, and visually sanitized community.

Having recounted Akosombo’s history, Miescher evaluates the legacy of Ghana’s venture into high modernist city planning:

“Thus, is Akosombo just another instance of failed modernization, of which there are many in postcolonial Africa – another example of the ‘flaws of hubris in high-modernist urban planning’…?…Not quite. Akosombo continues to be an attractive place to live. While most urban areas in Ghana have chronic power failures, insufficient water supplies, roads with potholes, and limited health care, the infrastructure at Akosombo remains among the country’s best and the reputation of its schools and hospital ranks high. Akosombo is the township that works.”

Just because a city does not fulfill the original (often high modernist) vision laid out for it does not automatically doom it to failure, and Miescher does a great job not following into the easy mistake of tossing Akosombo into the pile of failed planned African cities just because it did not follow the original vision of Doxiadis to a T. What I think separates Akosombo from the pile is that there was a continued dialogue (even if contentious at times) between its residents and the government and instead of the Combine simply being torn down, a solution was arrived at that seems reasonable and allowed the city to continue functioning and serving its residents. The other day I was reading Philip Harrison’s article (On the Edge of Reason:  Planning and Urban Futures in Africa) in which he draws on post-colonial theory to arrive at a theoretical approach to planning in Africa that balances planners’ desires for efficiency and order with the wisdom found in the “multiple rationalities” of local residents of the Global South. The abstract notion of what Harrison wrote seemed to be sensible, but he was only able to point to Johannesburg as what to avoid, which made reading about the concrete example of Akosombo’s success extremely refreshing. This is the kind of project that planners can build off of for future African cities, striving for what Miescher calls “high modernist local knowledge.” And is why historical awareness and a long view of history is essential to planning.

The only thing that I wish the article had gone farther into was the design of the individual houses–how residents found the boxy (western) style, how the material held up over time, and what alterations residents undertook. Images of Akosombo:

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BUILDING THE CITY OF THE FUTURE: VISIONS AND EXPERIENCES OF MODERNITY IN GHANA’S AKOSOMBO TOWNSHIP