The Geographical Spread of Ebola 2014

(also check out Mapping Ebola 2014)

The Ebola outbreak of 2014 is the worst on record. The current outbreak has sent shock waves throughout the international system. There are heightened irrational fears and anxieties about the Ebola spreading to every other corner of the globe. Just like the early days of HIV/AIDs, a virus-hysteric global populace, and a sub-group within this populace that is Africa-phobic, are doing untold damage to the region by recovering the old colonial era representation of “Africans and disease.” Ebola misinformation is all too apparent on social media, e.g. twitter, without much realistic assessment of the geographical spread of Ebola in order to determine the past as well as the potential future geography of the disease.

Unfounded fears about the virus have also been common on the ground in local communities where the outbreaks have occurred.  Rural communities in West Africa distrust of government information and unrealistic expectations of international public health officials sent into their communities has not helped contain the spread of the virus. Rumors of the virus being a hoax are commonplace. Local resistance to acknowledging Ebola and medical staff shortages are producing a lethal situation. Because there is no known cure many families opted to keep Ebola-inflected relatives at home. Large “shadow zones” in rural areas have emerged where Ebola contagion proceeds. In urban areas, combinations of disbelief and anxiety among city inhabitants challenge the establishment of quarantine and isolation centers in my backyard (NIMBY). Controversially West Point, a large slum community (the estimated population is 70,000) in Monrovia, Liberia has been sealed off and quarantined in a government effort to isolate cases among the poor and contain the virus.

So far, the West African 2014 outbreak has spread from Guinea to four countries in the West Africa region: Sierra Leone, Liberia, Nigeria and Senegal. Over 1,427 people have died (as of August 25, 2014) and over 2,615 people have been infected, and the tally continues to grow. False alarms about the virus spreading to adjacent Ghana and Côte d’Ivoire have also occurred. Suspected but not-confirmed cases have been registered in numerous countries including the UK, Ireland, Canada, and the United States.  A second outbreak of Ebola in DRC was confirmed on August 25th but the strain is different to the West African strain. Importantly, contagion is neither as simple nor as quick as Hollywood portrays.

Source: WHO (2014)

A key question is how did the deadliest strain of Ebola erupt in Guinea, some 2,500 miles away from the location of the first outbreak in DRC, and why has a separate outbreak occurred in DRC? Experts differ on why the outbreaks have occurred as well as about the main triggers of contagion.

Ebola is another of the emerging infectious zoonotic diseases i.e., a disease that originates in animal populations and jumps to humans. In the twenty-first century 60% of infectious diseases in humans are zoonotic. Detection in animal populations is complicated as the pathogen can live in animals, and in many cases without the host contracting the disease. We still do not know its animal origins but most experts believe straw colored fruit bats serve as the reservoir population but rodents and small birds might also act as intermediate hosts. Colonies of these bats migrate over long distances but it seems unlikely that bats migrated from DRC to Guinea, and it it is more plausible that a chain reaction occurred where the virus spread from one bat colony to another. The Ebola virus has decimated the gorilla population in Central Africa, and the virus has killed many more gorilllas than humans.

Two major conflicting theories based on different assumptions of the Ebola’s macro-geographical patterning are advanced by popular science writer David Quammen’s (2013) Spillover: Animal Infections and the Next Human Pandemic. W.W. Norton & Company. The first perspective offers a particle view of Ebola that contextualizes the virus as an old and ubiquitous strain within Central African forests, and each human outbreak represents an independent event, primarily explicable by an immediate cause. For example, “somebody scavenges an infected chimpanzee carcass; the carcass is infected because the chimp previously scavenged a piece of fruit gnawed by a reservoir host.” The subsequent outbreak from humans, therefore, results from a local accidental episode that is discrete event. It may be that the virus is present all of the time within reservoir species but sometimes a transmission from species to other species occurs and a geographical breakout occurs. This might explain how two different strains could emerge in 2014: one originating in Guéckédou, Guinea and the other in Djera, DRC, a village 1,200 kms from Kinshasa.

The second perspective offer a wave view and is built upon the premise that Ebola has not been present throughout Central Africa for a long time but rather that it is a new virus that is diffusing to various sites. Therefore, local outbreaks are not independent events but rather part of a new wave phenomenon that has been moving in time and across space, infecting new populations in new places.

The mechanisms by which the virus spreads geographically are hotly debated and various pieces of evidence are put forward.

It is evident that human activity is playing a major role in the initial outbreak of zoonotic diseases. Humans are venturing deeper into forests, accelerating the pressures on local ecosystems through artisanal mining, deforestation (via logging, slash and burn agriculture and searching for firewood to sustain larger urban populations). During civil wars in Sierra Leone and Liberia refugees fled into forests and livelihoods became dependent on forest animals for food, forest wood for fuel and building materials. Human incursions are altering animal habitats and causing people and wildlife to have more contact. Mining and logging, in particular, entail immense movement to and from forest sites and embed forests within broader circuits of labor (drawing in seasonal workers often from other rural areas) as well as commodity chains (international timber exports from African port cities).

Human–induced climate change is also having an effect. Heat waves, season droughts, strong winds, floods, thunderstorms and changes rainfall patterns are also altering the ecosystems where Ebola takes hold.  Changed conditions in forest may also be affecting the range of fruit bat habitats and forcing the species to live in great numbers amongst human populations in rural villages.

The possibility of primate traffickers based in Guinea with familial relations and business connections to wildlife traffickers in DRC has been touted as another explanation of how the virus erupted in Guinea. Traffickers from Conakry are known to engage in the illegal trafficking of ape infants in trade circuits that extend from the DRC to Guinea and that connect to international markets as far away as China. Under this scenario an infected ape or a wildlife trafficker could carry the virus from the deep within the forests of DRC to Guinea.

Bush meat (cooked, dried or smoked remains of wild animals such as rats, bats and primates such as monkeys, chimpanzees and gorillas) may be a bridge that enables the deadly disease to go from the animal to the human world. For example, fruit bats can be smoked, grilled and/or put into soups. Bush meat is widely harvested for consumption and for commerce in the region. Bush meat is an important source of protein in poverty-stricken rural communities.  Around the world, bush meat plays a direct role on the livelihoods of nearly 150 million people and millions of tons of bush meat are harvested in Africa every year. Central Africa is the epicenter for bush meat trade and consumption, and wild game is also widely consumed in rural West Africa. In Central Africa bush meat accounts for 80% of protein and fat needed in rural diets. According to this popular theory, hunters kill and touch the infected animals and transport it to markets where others prepare, cook and sell the meat (which may not be cooked properly), thereby opening up an Ebola diffusion channel.

The cultural and practices of this region regarding caring for the ill in inadequate and impoverished health systems as well as the role of family members (especially women) in preparing the body of the deceased for burial means that an extended community come into direct contact with the ill, and the body upon death as families perform honoring rituals. Washing, touching, dressing the body in a favorite outfit and kissing a beloved deceased on the face (known as “a love touch”) – typical in many West African countries – can be deadly. Fluids outside the body that are secreted on the skin of the dead for several days after passing contain a high concentration of the virus that is highly contagious. Stopping burial rituals can be very problematic because improper burial is believed to cause harm and trigger illness for family members. Banning these rituals often means that the practice continues but it is hidden, complicating the detection and surveillance within highly vulnerable communities.

Claims by traditional healers that they can cure Ebola may have ignited Ebola sparks. Superstitious beliefs in some parts of West Africa that that simply saying “Ebola” aloud makes the disease appear also impede the containment of the virus.  The media has widely reported that the claims of a herbalist located in Sokoma (a border village in Sierra Leone close to Guinea) that she could cure Ebola may have unwittingly been responsible for infected patients crossing from Guinea into the neighboring country and unleashing a cross-border Ebola spark.

The poor are typically the first to suffer in infectious disease outbreaks in Africa. Living in impoverished communities with inadequate health infrastructure, rural populations are triply burdened by lack of knowledge about how disease is transmitted and diffused – especially unfamiliar and episodic ones such as Ebola – and by the lack of a vaccine to treat the virus as pharmaceutical conglomerates allocate more effort to research and development in breakthrough drugs for conditions that can generate them more profit. The incubation period ranging from 2-21 days from transmission to full-symptoms (high temperatures > 38.6°C or 101.5°F, severe headache, muscle pain, weakness, diarrhea, vomiting, abdominal pain etc.) complicate the diffusion of the virus.  Importantly, the virus can only be spread after symptoms begin. Without proper surveillance mechanisms, mapping the spread of the virus is problematic and underreporting of cases is to be expected.