farmingpathogens | In spite of writing a long book on diseases spilling over from animals to humans, well-regarded author David Quammen can’t seem to get his mind wrapped around the possibility Ebola has likely evolved a new ecotype, for the first time spreading into a major urban area.
The first outbreak of Flaviviridae Filoviridae Ebola in West Africa apparently began in forest villages across four districts in southeastern Guinea as early as December 2013 before spreading to Conakry and the outskirts of Monrovia, the capitals of Guinea and Liberia respectively.
The number of deaths across West Africa presently stands at 149 killed out of 242 infected. According to the WHO, with a three-week incubation period cases are likely to continue to accumulate for months.
To date, researchers have identified five ebolavirus types. A new clade of Zaire ebolavirus characterizes the present outbreak.
Many of the human outbreaks since 1976, until now limited to Central
and East Africa, began with the ingestion of an infected monkey or fruit
bat of the Pteropodidae family or some such combinatorial of ecological pathways. In short, one of Quammen’s spillovers.
A human infection typically leads to fever, diarrhea, vomiting, hemorrhage, and death.
Ebola is difficult to contract from another human, however. Much like
HIV it spreads by bodily fluid, including, alongside ingestion and
accidental cuts, sexually. Its virulence, producing case fatality rates
as high as 91%, usually burn out outbreaks. Patients die faster than susceptibles are infected.
And yet this new strain has found the geographic momentum and multiple transmission chains associated with a virus experimenting with evolutionary possibilities, including a more widespread epidemiology.
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History offers multiple examples of pathogens successfully making such sociospatial transitions.
For most of its evolutionary history the cholera bacterium ate
plankton in the Ganges delta. Only once humanity urbanized and by the
19th century became spatially integrated by new modes of transport was
cholera able to make its way to the world’s cities. There, in a kind of microbial Bildungsroman,
the bacterium transformed from a marginal bug into a roaring success
when municipalities began drawing drinking water from the same place
they dumped their shit.
The simian immunodeficiency viruses that would evolve into HIV likely emerged from Cameroonian forests when colonial logging broadened the wildlife-human interface.
For eons influenza cycled across waterfowl populations that summered on the Arctic Circle. Influenza expanded into
humans once we became farmers and our population densities and
connections grew enough to support such an acute infection. After WWII
influenza entered
its Industrial Revolution. Billions of livestock monoculture are now
pressed up against each other, permitting a new phase in influenza
evolution and spread.
In the guise of a liberal paternalism, Quammen errs on the side of an
essentialist Ebola instead, denying the virus its capacity to evolve
new identities under new circumstances,
Other work documents West Africa is undergoing massive changes in food production and forestry driven by the neoliberal program. “In West Africa,” writes William Moseley and colleagues,
the resulting neoliberal economic policies sought to promote growth and prosperity through structural adjustment programs (SAPs) that generally involved contraction of government services, renewed export orientation on crops or goods deemed to have a comparative advantage, privatization of parastatal organizations, removal or reduction of many subsidies and tariffs, and currency devaluations.
The area is part of the larger Guinea Savannah Zone the World Bank describes as
“one of the largest underused agricultural land reserves in the world”
that the Bank sees best developed by market commercialization, if not
solely on the agribusiness model.
Indeed, the initial outbreaks appear within the cycle migration
range–about 120 miles–of recent land deals pursued by the newly
democratized government of Guinea.
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