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Nearly a thousand are dead in Africa, three times the previous worst death toll; only 1 in 3 survive

The media wasn't exactly an invited guest at Dobbins Air Reserve Base in Marietta, Georgia on Tuesday morning.  On the runway a nondescript gray Gulfstream III jet touched down quietly and safely, transporting a desperately ill American missionary to a top research hospital for a treatment, as the threat of a global pandemic looms on the horizon.
 
I. A Category A Bioweapon -- One of the Deadliest Diseases Known to Man
 
The landing echoes Guillermo del Toro's The Strain.  Inside the plane lurks a deadly pathogen, a disease that could kill millions -- if it were to escape containment.  Much like the primetime horror series, the culprit is a tiny worm -- in this case a nanoscope worm-like "filovirus", the Zaire ebolavirus (ZEBOV).
 
But this is no fiction novel.  This is real life.

Zaire ebolavirus
The Zaire ebolavirus [Image Source; Wikimedia Commons]

Ebola comes on like more mundane, more easily treated viruses like influenza (caused by viruses in the family Orthomyxoviridae), malaria (caused by protozoan species in the genus Plasmodium) or cholera (caused by the the bacterium Vibrio cholerae).  But quickly, the Ebola virus (EBOV) distinguishes itself from common respiratory ailments, showing why it's classified as a potential Category A bioweapon -- the most deadly of three classes of weaponizable infectious agents.
 
Under the standard transmission scenario the virus invades the skin (endothelial cells).  Much like the human immunodeficiency virus (HIV) it's believed to sneak into cells via the Niemann Pick, type C (NPC1) transmembrane protein, which typically transports lipids into the cell.  
 
Although it is incredibly simple, only encoding a couple of proteins, the deadly virus makes them count.  The virus uses its Swiss Army knife protein -- the Ebola glycoprotein (GP) -- to latch onto the membrane.  Unaware of the dangers facing them, the cells transfers the virus inside, thinking it’s a nourishing lipid.
 
It can also jump directly into the bloodstream latching onto and infected cells in a similar matter.  Once in the bloodstream, one of its first targets is monocytes (mononuclear phagocytes).  While not a direct enemy of the virus, the attack on the body's vanguard against bacterial infection causes stress on the system.

Ebola pathenogenesis
Ebola attacks phagocytes in the blood stream.  It then attacks vascular edothelial cells to encourage hemorrhaging and builds up in the liver's hepatocyte population, keys to its spreading to new host.
[Image Source: Wikimedia Commons] 

From the bloodstream, the virus launches a fresh attack, using the GP in a second way.  A pair of GP proteins dimerize to form a compound that interferes with neutrophil activation.  Antibodies are relatively ineffective against the long slender filovirus.  The body's best hope would be neutrophil activation.  

Normally the neutrophils would activate and swallow the diseased endothelial cells and phagocytes as they emitted cytokines, destroying them in a torrent of protein-catabolizing proteases.  But jammed by the dimer, the neutrophils are unable to activate and watch helplessly as the bloodstream is engulfed in filamentous viral vectors.
 
Lastly, three GPs trimerize to latch the incognito infect cells onto the wall of blood vessels, where they lurk infecting phagocytes, as well as endothelial cells in the walls of the blood vessel.  The disease also travels to the high vascularized liver where it infects hepatocytes, crippling the body's ability to filter out toxins from the bloodstream.  In time the blood vessels of an Ebola patient are coated with tiny berry-like collections of adhered, infected cells, invisible to the naked eye.  As the infected endothelial cells in the walls of the blood vessels emit an inflammatory (cytokine) response, the already stressed blood vessel begins to leak and rupture.  Thus begins the Ebola hemorrhagic fever (EHF).
 
It is a simple but deadly strategy.
 
II. Epidemic Reaches Unprecedented Death Toll
 
Historically speaking no major Ebola virus outbreak has seen a survival rate higher than 50 percent.  The strain that's been confirmed to be involved in the current outbreak (ZEBEV) was the first of several strains to be discovered, when it raged through Zaire (now the Democratic Republic of Congo) in August 1976.  Medical aid workers and researchers recognized quickly that this was a new disease, given that it killed an astonishing 280 of the 318 people in infected -- an 88 percent mortality rate.
 
Thus the bad news is that -- historically speaking -- the strain of Ebola virus that's believed to be burning up central African nations of Guinea, Liberia, Sierra Leone, and Nigeria, ZEBOV, is the deadliest kind of Ebola virus (EBOV).  The good news is that thus far the mortality rate has been relatively "low" by ZEBOV's standards -- only around 60 percent.
 
Ebola epidemic
The epidemic continues to grow as the death toll rises.  Most worrisome, Nigeria, Africa's most populous nation is beginning to see cases. [Image Source: Samaritan's Purse]

But the very bad news is that the virus appears to be spreading faster than ever before.
 
Over the weekend the World Health Organization (WHO) announced that 887 people had died through Aug. 1, since the April 2014 onset of the latest epidemic.  In total 1,603 people are known to be infected.
 
Those numbers are very alarming. Previously EBOV outbreaks of various strains had killed over 200 people only three times -- during the original 1976 outbreak of ZEBEV, during another outbreak of ZEBEV in 1995, and during the 2000 outbreak of the Sudan ebolavirus (SEBOV) in 2000.  And until this year, the original infection was the deadliest.
 
Ebola Spread
Nigeria, the Ivory Coast, and Senegal, are among the neighboring countries at risk. [Image Source: CDC]

Something has changed.  After years of small outbreaks, this year's violent epidemic has not only surpassed the previous record-holding death toll of the 1976 outbreak; it's tripled it.  No one is sure if this is simply a mix of bad luck and circumstances, or something more sinister.  But with Nigeria reporting its second death from the disease this week, things are looking grim.
 
If the disease picks up in Nigeria there's no telling when it will be stopped.  Nigeria is Africa's most populous country, and the seventh most populous country in the world.  It also sees a high amount of traffic into the U.S.
 
III. Airborne Ebola?  It's Possible, Although There's no Proof Yet
 
Also alarming is the number of medical workers getting infected with the disease.  Occasionally doctors and nurses treating the disease in the past have come down with the disease.  But the current outbreak has seen several American and European doctors and nurses become infected, despite appearing to follow sound containment protocols.
 
Traditionally the disease was transmitted via body fluids -- typically passed by having sex with an infected person or touching their exposed skin.  A 2012 study published in Nature by researchers with the Canadian government and the University of Manitoba showed the disease could potentially be mutating to be transmissible via airborne droplets, a far more potent vector.

Rhesus macaque
Airborne ebola was shown to be capable of infecting Rhesus macaque monkies in a tightly controlled 2012 study. [Image Source: Mark Snelson]

In the study a group of Landrace piglets (Sus scrofa) infected with ZEBOV passed it over the air to a group of Rhesus macaques (primates) in a separate cage, despite attempts to prevent any inadvertent transfer of materials.  It appeared the disease "went airborne" transmitting without the traditional route of direct skin contact.
 
While there's no sign yet that the current disease sweeping through Africa is airborne, between the large number of medical professionals infected and the unprecedented death toll, fears are growing it might be.
 
At least one American citizen in the region already lost their life to the disease.
 
IV. Pair of American Ebola Victims Arrive Home for Experimental Treatment
 
Under that backdrop Nancy Writebol, 59, arrived in Georgia on Tuesday, after the Gulfstream III jet transporting her made a pit stop in Maine on Monday to refuel.  An American citizen and North Carolina native, Ms. Writebol is headed for an isolated care unit at the Emory University Hospital near Atlanta.

Nancy Writebol
David Writebol and Nancy Writebol (right) were tirelessly committed to helping the ill in Africa.  Now Nancy is fighting for her very life. [Image Source: Samaritan's Purse]

Ms. Writebol was a missionary with Serving in Mission, a nonprofit which looks to provide healthcare and life-saving treatments in impoverished regions.  A married mother with two children, Ms. Writebol was the head of the decontamination team of the ELWA (Eternal Love Winning Africa) hospital that SIM runs in Paynesville City, Monrovia, Liberia.  A press release describes:

She had been working as a hygienist who decontaminated those entering and leaving the isolation ward of the Case Management Center at the hospital.

To transport the missionary safetly to the U.S. without exposing other doctors and physicians, the U.S. Military tapped the "Gray Bird 333", a GulfStream III jet.  Sold by General Dynamics Corp.'s (GD) Gulfstream Aerospace unit to Denmark, it had served for a time as the F-313.  In 2005 it returned to its homeland after it was purchased from the Royal Danish Air Force by Phoenix Air, who proceeded to retrofit the roomy craft for medical evacuations.
 GulfStream III open
One of the GulfStream III medivac craft [Image Source: [Image Source: Phoenix Air/Gentex/CDC]

The plane is equipped with extensive monitoring equipment and is most crucially equipped with a Aeromedical Biological Containment System (ABCS), which keeps an infections patient covered in a negative-pressure tent.

ABCS unit
The negative-pressure Aeromedical Biological Containment System (ABCS) keeps the crew safe from their infectious patient. [Image Source: Phoenix Air/Gentex/CDC]

Without the ABCS, the plane's pressurized interior would likely vaporize pathogen droplets and infect the medical staff aboard.  With the ABCS, they were able to safely sojourn back to U.S. soil.

Ebola jet transport
The GulfStream III carrying the second U.S. ebolavirus patient arrived in Georgia this morning.
[Image Source: WLBZ]

The U.S. military's non-combat air service operator, Phoenix Air, manages a pair of the specially outfitted medivac craft.  Last Friday the second, almost identical Gulfstream III flew Dr. Kent Brantly, a U.S. doctor infected with ebola out of Liberia.  Dr. Brantly is currently being treated in isolation at Emory University Hospital as well.

Ebola case Dr. Brantly
Once in charge of a major ebola treatment clinic in Africa, Dr. Brantly is now battling for his life.
[Image Source: Samaritan's Purse]

Dr. Brantly had been serving as medical director at a clinic of SIM's partner Christian missionary organization, Samaritan's Purse.  A married man, the veteran doctor is now adjusting to the role of fighting for his life as a patient.

Dr. Brantly
Dr. Brantly is seen in a June photograph wearing protective gear as he treated patients with the ebolavirus in a special isolation ward. [Image Source: Samaritan's Purse]

Before joining up with Samaritan's Purse, Dr. Brantly had gone through his residency at John Peter Smith Hospital in Fort Worth, Texas.  He also has two children of his own.  His wife and children were living with him in Liberia, but were fortunately sent home as the crisis heated up.  Now his children are praying their father survives the terrible virus.

V. Prepping for Potential Quarantine on U.S. Soil

In Africa, the disease has now swept into three capital cities -- Monorovia, Liberia; Freetown, Sierra Leone; and Conakry, Guinea in the northeast.  The epidemic started in Guinea in April, slowing gaining steam in May in Liberia and Sierra Leone.  Now the same thing is happening in Nigeria.

Samaritan's Purse and SIM have both vowed to stay in the region, although they've evacuated non-essential personnel, such as family members and bookkeepers.

Other organizations are pulling out everyone.  The Peace Corps is ordering all 340 of its volunteers in the three worst-struck nations to go home; two of its volunteers are in quarantine after being potentially exposed to a person who was later diagnosed with the disease.

Doctors without Borders
A Doctors Without Borders staffer hands out supplies to relief workers. [Image Source: MSF]

Other organizations are doubling down.  Doctors Without Borders is calling for a massive deploymenet to stop the spread of the disease before it takes off in Nigeria.  Many in the group expressed faith in the effort despite the danger.  Doctors Without Borders nurse Monia Sayah told The LA Times:

We have very strict measures to avoid infection. We use a set of behaviors. It's very important the way we dress up and the way you dress down. We use a buddy system to make sure you don't make a mistake when you are putting on or taking off the gown.

The group exercises the strictest quarantine procedure, never approaching closer than two yards when assessing sick people during outreach journeys without protective equipment on.  When treating patients the doctors always wear a facemask and protective equipment.  The group claims never to have lost a doctor or nurse in the field to disease.

A recent press release says that the group has 300 staff members, including hundreds of doctors, in the three worst afflicted countries and over 40 tons of medical equipment in hopes of evening the odds with the ZEBOV.

But despite its major commitment the organization finds itself struggling to keep up.  Dr. Bart Janssens, its chief, said last month:

The epidemic is out of control.  With the appearance of new sites in Guinea, Sierra Leone, and Liberia, there is a real risk of it spreading to other areas.

We have reached our limits.  Despite the human resources and equipment deployed by MSF in the three affected countries, we are no longer able to send teams to the new outbreak sites.

But the question remains whether the WHO and The Centers for Disease Control (CDC) in the U.S. are truly moving aggressively enough and heeding the call.

The WHO committed 120 doctors and staffers.  The CDC is also sending an additional 50 experts in coming weeks.  Backed by the U.S., the WHO also pledged $100M USD to the region to fight the disease.  But the timeframe for that aid money disbursement is unclear and it's also unclear whether it will be enough to combat the increasingly expensive epidemic, which has no real cure.

VI. Health Ministry Targeted by Angry Family Member of Ebola Victim

In Liberia, the situation is growing increasingly grim.  President Ellen Johnson Sirleaf has order all government employees to return home, and has ordered schools to cancel classes.  The national economy has ground to a halt, and yet the disease continues to spread.

Liberia President
Liberian President Ellen Johnson Sirleaf is facing growing security risks and unrest as the epidemic continues to grow in her nation. [Image Source: Facebook]

She beseeched her citizens to practice more careful hygiene in a recent speech, remarking:

My fellow Liberians, Ebola is real, Ebola is contagious and Ebola kills.  Denying that the disease exists is not doing your part, so keep yourselves and your loved ones safe.

The disease likely arrived via the local practice of hunting for bushmeat, which the impoverished locals regularly engage in, to gather enough to eat.

Many of the local fruit bat populations harbor traces of the disease.  Indeed, doctors today believe that the bats were original reservoir species.  The nocturnal flying mammals are eating across much of the region.  So too are primates.  While monkeys are less frequent carriers of the diseases (and it tends to kill them, as it does humans), their consumptionalso raises the local risks.

Fruit bat
Fruit bats, nocturnal herbivores, are consider a bushmeat delicacy in Western Africa.  Unfortunately, many of the flying mammals carry the ebolavirus, leading to regular outbreaks. [Image Source: Getty Images]

But there's growing rumors and suspicion in the region among locals.  They believe that the U.S. may have pruposefully released the disease as some sort of weapons test.  One local man who lost his teenage brother to the disease set fire to the Healthy Ministry building in the capital city of Monorovia.

Also many are resisting travel bans.  Liberia promised to beef up security after a ebolavirus victim successfully circumvented airport security and boarded a plane to Nigeria.  President Sirleaf said the security situation would be rectified.

The growing civil unrest and anger is stalling already beleaguered aid efforts from Doctors Without Borders and international government groups.

VII. Quarantine Centers are Readying Themselves in Case Disease Reaches U.S.

The Centers for Disease Control (CDC) appears to be moving cautiously when it comes to slowing the infection in Africa.  It's sending 50 doctors and other medical experts to Western Africa in coming weeks to assess the situation and try to improve it.  But it hasn't been cautious to commit to larger deployments of staff or supplies as the situation in the region continues to grow more dangerous.  

The CDC's primary focus seems to be more on keeping the disease out of the U.S.  Back home it's issued its highest level of travel warning -- Level 3 -- urging Americans to avoid travel to the region.

It believes these precautions will keep ZEBOV out of the U.S.  But just in case, it's already prepping twenty quarantine camps in major cities around the country.
 
Dr. Hector Ocaranza, the health authority for the El Paso, Texas City/County Health Department said the preparations are just a precaution and not cause for panic.  El Paso is home to one of the quarantine camps that might be called upon, should the disease pop up in the U.S.  Speaking to ABC News, he commented:

It's a scary virus ... Definitely terribly deadly. It's one of those viral hemorragic fevers. They haven't found where it's coming from, if it's coming from an animal to the human or what. But we know there is human tissue transmission.

I don't think we should be concerned, even if we're on the list of quarantine stations.  I don't think we should be concerned with these kinds of viruses. It is still contained within Africa, unfortunately it has been one of the largest outbreaks of this virus and it has a high mortality.

The CDC is also coordinating closely with the Mexican Department of Health, the Public Health Agency of Canada, and Canadian Institutes of Health Research to prepare a unified response if the disease appears at a border region.


CDC Quarantine Station

Both patients are believed to be in serious, but stable condition.  They are expected to receive an experimental drug designed to boost their immune system.  While not a true vaccine, doctors are hoping the antibody formulation will help the patients' battered bodies to naturally fight off the disease by jump-starting neutrophil antibody production.

Sources: AP News, AP on Fox News, CDC [Quarantine Station List], Samaritan's Purse [press release]



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By DaBoSSs on 8/5/2014 8:36:07 PM , Rating: 2
Red blood cells are erythrocytes, not hepatocytes. Hepatocytes are the cells that make up the parenchyma of the liver.


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