The world is on alert as Ebola epidemic claimed several lives in Africa. The latest and the first outbreak of Ebola virus in west Africa is the worst ever and this is the deadliest (''zaire") strain to infect human beings say the experts. Guinea, Liberia and Sierra Leone all have confirmed cases. And it is spreading very fast.

Usually world alert will be given by WHO and asks the countries around to take precautions. So how is the world health organization dealing with it. This video shows the procedure followed:

Ebola virus disease (formerly known as Ebola haemorrhagic fever) is a severe, often fatal illness, with a case fatality rate that ranges from 50 to 90%. It is one of the world’s most virulent diseases. Ebola is a virus that is named after the Ebola River in the Democratic Republic of Congo, where it first was identified in 1976. There are currently 5 strains of the virus, with 4 out of the 5 causing disease in humans. It is suspected that it first originated from fruit bats, and then spread to humans. The infection is transmitted by direct contact with the blood, body fluids and tissues of infected animals or people. To become infected in the first place, a person's mucous membranes, or an area of broken skin, must come into contact with the bodily fluids of an infected person, such as blood, urine, saliva, vomit, semen or stools, materials contaminated with these fluids such as soiled clothing or bed linen, needles or non-sterilized medical equipment, contact with blood or fluids of infected animal meat. It is the cause of a very threatening illness called “hemorrhagic fever,” where the term “hemorrhagic” refers to bleeding that is often accompanied by a high fever. This bleeding is often caused by Ebola’s effects on the liver, which normally produces the necessary clotting factors to stop bleeding when it occurs. If the clotting factors are no longer being produced by the liver the way they should be, then the patient can experience excessive and prolonged bleeding. This bleeding can be external or internal, and can involve multiple organs, such as the kidneys, brain, and lungs. Unfortunately, Ebola has a high risk of mortality associated with it, and majority of those who contract it eventual die from organ failure, due to bleeding and/or shock.

Severely ill patients require intensive supportive care. This is difficult because they will have to be isolated to control the spread of the disease. During an outbreak, those at higher risk of infection are health workers, family members and others in close contact with sick people and deceased patients. Safe burial practices or safe preparation of the body for funeral is critical.

Ebola virus disease outbreaks can devastate families and communities, but the infection can be controlled through the use of recommended protective measures in clinics and hospitals, at community gatherings, or at home.

Experts are still unclear about where Ebola comes from. There are documented cases of contracting the virus after someone is exposed to a fruit bat, bush meat or encountering an infected porcupine, but it’s undeniable that once the chain of human-to-human transmission gets going, it is deadly.

The incubation period of Ebola virus disease (EVD) varies from 2 to 21 days. Person-to-person transmission by means of direct contact with infected persons or their body fluids/secretions is considered the principal mode of transmission. In a household study, secondary transmission took place only if direct physical contact occurred. No transmission was reported without this direct contact. Airborne transmission has not been documented during previous EVD outbreaks.
Therefore, the governments in countries this outbreaks occurs must restrict movement, get people into hospitals with proper hygiene practices and set up field hospitals where necessary.
The World Health Organisation estimates that there is a high risk of spread to countries bordering those with existing outbreaks, a moderate risk to countries further afield in the sub-region, but that there is little chance of spread overseas. There is no reason to assume that an exported case — be it to Lagos, a city of 17 million people, or any other place — will spark new outbreaks, because Ebola is not very highly contagious.
Ebola can look like flu at first, causing fever along with head and muscle aches. In latter stages it can progress into diarrhea, vomiting, rash and bleeding, ultimately leading to organ failure.

There is no risk of transmission during the incubation period and only low risk of transmission in the early phase of symptomatic patients. The risk of infection during transport of persons can be further reduced through use of infection control precautions

The Ebola virus is usually transmitted by close contact and the first cells it affects are cells important to your primary immune response—monocytes, macrophages and dendritic cells. These cells are important because they’re the first to recognize that something foreign has entered your body and the first cells to trigger your innate immune system to fight off the infection. By attacking the body's first responders, the virus cripples the immune system before it can mount an effective defense . This makes it hard to mount an effective immune response against the virus—your body has a tough time fighting the virus off, and the virus multiplies to the point that it takes over major organs in your body.

One of the greatest challenges with Ebola is that there is no cure. Like many other viruses, once contracted, it needs to run its course. Also, like other viruses, it requires certain supportive measures to mitigate its effects while it runs its course--like providing IV fluids, controlling the bleeding and low blood pressures, fever control, maintaining oxygenation, etc. No specific treatment for Ebola currently exists, but several investigational drugs are under development. It’s not very realistic for such a virus to spread as rapidly in developed countries and countries that take adequate preventive measures no matter how much drama and fear the media likes to create.

There are no effective vaccines or therapies for Ebola. It takes years to develop⁠ and bring a drug or vaccine through all phases of clinical treatment. So health care workers can only attempt to support patients’ immune systems (regulating fluids, oxygen levels, blood pressure and treating other infections) to help the afflicted fight off the virus as best they can.
A vaccine is a few years away. There are quite a few preventative vaccines in development, with three to five that have been shown to completely protect nonhuman primates against Ebola. The pharmaceutical companies are not much interested in developing a vaccine that treats little outbreaks every 3 or 4 years! Since Ebola first appeared in 1976, only 19 outbreaks have had more than 10 victims, and around 2,000 people in total have died from the disease.This is the main reason why there is no vaccine till now.
But how a vaccine, if developed, works in these cases? The vaccine VSV is probably one of the most promising, and it’s based on a viral vector related to the rabies virus. It’s a bullet-shaped particle, and on its surface is a structural protein called a “glycoprotein,” which allows a virus to recognize a host cell, bind to it and take over the host cell’s machinery. With a vaccine, we remove the gene that encodes the glycoprotein of the VSV virus and we replace it with a gene that encodes the glycoprotein of Ebola. You end up with a vaccine that has an Ebola glycoprotein on the surface. Now, it doesn’t behave like Ebola because the rest of its genome is not Ebola, but because it has the Ebola glycoprotein your body is going to recognize it as foreign and build up an immune response against Ebola.
An experimental drug given to two American patients with Ebola is made from tobacco leaves and is hard to produce on a large scale. Known as ZMapp, the serum consists of three antibodies manufactured in modified tobacco leaves, which take weeks to grow.
It was reportedly rushed to US missionaries Kent Brantly and Nancy Writebol, who were stricken with Ebola while treating patients in Liberia. Both have shown improvements in their health and are now being treated in isolation at an Atlanta, Georgia hospital. But we cannot say right now that this drug is particularly promising. The animal data during the experiments with them are very good and the use of it in the two patients is suggestive that it may have a favorable effect, but since there are only two patients, you have to be careful about making any definitive decision. With ZMapp, which was first identified as a drug candidate in January this year, there have been no safety tests yet in humans.
According to WHO, blood transfusions from survivors is one of the best way to fight Ebola.
A panel of experts from the World Health Organization says blood plasma and whole blood transfusions should have priority for now because survivors of an Ebola infection would typically have produced effective antibodies against the virus (otherwise they wouldn't have survived), transfusions of their blood into a newly infected individual may help that person survive the often fatal disease. Such blood preparations, drawn from volunteers, could be ready before the end of 2014.
Right now, though, all that people can do to protect themselves is take precautions, especially while traveling.
Ebola Declared a Public Health Emergency by WHO on August 8th, 2014.

Ebola survivors struggle with new symptoms like brain deficits, memory loss, depression, anxiety, throbbing headaches, hip and knee aches, muscle aches, sleep disorders, and hearing loss. Eye burning and pain are highly prevalent, sometimes they make  the world appear cloudy or foggy. Eyes also become sensitive to light. More than half of the patients who lived through an acute attack later reported muscle and joint problems. Two thirds had neurological difficulties and 60 percent reported eye problems - including blindness - approximately one year after Ebola infection.  A new study hints at hidden virus remnants or immune system overreaction. Doctors began referring to this constellation of symptoms as post-Ebola syndrome. 

Recent update: 6th Aug., 2015...from The Lancet

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2815...

For the first time, there is evidence that a vaccine protects people from Ebola. The interim study results, unveiled by the World Health Organization on July 31 and published online by The Lancet, suggest that a single shot can protect people who were directly or indirectly exposed to individuals with the disease. The vaccine, which appears safe, could fundamentally alter how well humans contain future Ebola outbreaks.
This vaccine was being tested in people living in Guinea and is based on an animal virus that primarily affects rodents, cattle, swine and horses. One gene of that virus, however, was replaced with a segment of the gene for the outer protein of an Ebola virus species.
The only individuals in the trial were those who had been exposed to newly identified Ebola patients or were those contacts’ contacts. This unique study approach, called “ring” vaccination, is based on the smallpox eradication strategy. It effectively forms a “ring” of protection by targeting individuals directly around the infected person and the people around those contacts’ contacts as well.
WHO says that this is a highly effective vaccine.

Updates:

15th Oct., 2015

U.K. Ebola “Relapse” Case Takes Virus Specialists to Uncharted Waters according to Reuters

Scottish nurse Pauline Cafferkey is in critical condition following "totally unprecedented" return of symptoms. Her case is different now because she has Meningitis Caused by Persisting Virus.
The case of Pauline Cafferkey, the first person known to have recovered from Ebola and then suffer an apparently life-threatening relapse, is taking scientists into uncharted territory.

The Scottish nurse's critically ill situation, described as "staggering" by one British virologist, signals just how complex and formidable a foe the Ebola virus may turn out to be now that scientists have the chance to study its survivors.

Previous studies and preliminary data from research in survivors of the vast West African outbreak have detected Ebola virus in semen, breast milk, vaginal secretions, spinal fluid and fluids around the eyes.

But scientific literature has never documented an Ebola relapse case before, meaning Cafferkey's is likely to generate great fear and anxiety for the 17,000 or so other Ebola survivors across West Africa.
This has never been observed before. Is this a one off? A very rare event? Or is this going to be quite common? The honest answer is we don't know!
Until researchers can study in detail and in large numbers of people the virus's long-term effects, each survivor, be they healthy or sickly, will be able to teach virologists more.
Preliminary data published this week has already forced a re-think on how long male survivors should be advised to abstain from sex or use condoms, with a study showing traces of Ebola can be found in semen of some men at least nine months after they first became ill.

Even if you don't have the virus in your bloodstream it can be hiding out. And we need to be aware of that because it's setting up the stage for potentially new outbreaks.
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First known case of sexually transmitted Ebola reported
Oct., 2015
A Liberian woman contracted Ebola in March by having sex with a survivor of the viral disease, researchers report. Using studies of both people’s viral genomes and of the people’s contacts with any other possible sources of the virus, the researchers conclude that the woman’s disease represents the first known case of sexual transmission of Ebola.

People ordinarily catch the often-deadly virus through direct contact with blood or other body fluids.

In this case, the two people had unprotected sex six months after the man got Ebola, and 155 days after his second blood test showed him to be clear of the virus. The genomes of the Ebola virus from the man’s semen and woman’s blood were not only practically identical but also different from all other Western African Ebola viruses that had been sequenced, researchers report October 14 in the New England Journal of Medicine.

Also appearing in the journal is a preliminary report that genetic material from Ebola viruses can persist in semen nine months after infection.

Both findings suggest that Ebola remains in certain parts of the body long after the blood is clear of the virus. However, in an opinion piece that accompanies the two research reports, Armand Sprecher of Doctors Without Borders in Brussels notes that more than 17,000 people survived the West African Ebola outbreak. “If sexual transmission from survivors were an important means of disease propagation, we would have seen a number of cases by now,” he writes.
Source: http://www.nejm.org/doi/full/10.1056/NEJMoa1509773