What is the Ebola Virus?
The Ebola virus is one of the most dangerous viruses in the world and is mainly native to West and Central Africa. It gained notoriety after the great Ebola epidemic in 2014. The high death rate of the sick and the extremely high risk of infection make this virus so dangerous. Sick people have to be treated in quarantine and infected dead people burned as quickly as possible to prevent further spread and contagion.
Where did his name come from?
The Ebola virus is named after the Ebola River in the northwest of the Democratic Republic of the Congo in Central Africa. The first outbreaks of Ebola fever occurred along this river in 1976. A total of around 300 people fell ill at the time, almost 90% of whom died.
In the recent past, too, there have been repeated small outbreaks in these areas. However, a cave in Uganda that is home to a certain breed of fruit bats is believed to be the starting point for the virus. Although the animals are carriers of the virus, they do not develop it themselves.Since humans use these fruit bats as a source of food, among other things, the contaminated meat repeatedly transmits the virus to humans, which can be the starting point for an epidemic.
How is the virus structured?
The Ebola virus belongs to the class of "Filoviridae", to which the Marburg virus also belongs. They have an elongated thread-like shape and have an RNA as the carrier of their genetic material. This is arranged helically and is held in place by proteins. The virus is about 700 nm long and has a shell.
Ebola virus strains
There are four types of Ebola virus that are relevant to humans, of which the Zaire Ebola virus is the most dangerous. It is primarily responsible for the high death rate from Ebola infection. The other three species are:
- Taï Forest Ebola Virus
- Sudan Ebola Virus
- Bundibugyo Ebola Virus
Another Ebola virus variant is the Reston Ebola virus. However, this subtype only affects macaques and pigs and is therefore harmless to humans.
What disease does it cause?
The Ebola virus causes the hemorrhagic Ebola fever with consumption coagulopathy and massive bleeding. Overall, this disease can be thought of as a strong, intermittent fever with impaired blood clotting. As a result of this disturbed blood coagulation, there is massive bleeding into internal organs, but also into superficial layers of the skin.
This is due to a loss of platelets and clotting factors as well as an injury to the blood vessel cells. The more fluid blood then succeeds in exiting the blood vessels. The sick bleed to death internally, which leads to an insufficient supply of the organs and ultimately to multiple organ failure. In most cases this means the death sentence for the sick.
Read more on the topic: Bleeding disorder
Which symptoms indicate an Ebola infection?
In the western industrialized countries, the travel history of a possibly sick person is a crucial component for a correct diagnosis. People infected with Ebola typically report stays in Central or West Africa.
The typical physical symptoms of the disease are similar to those of a normal flu or an influenza-like infection at the beginning, although the fever is very pronounced (up to 41 degrees Celsius). In addition, those affected often suffer from:
- Muscle and joint pain
- Painful enlarged lymph nodes in the neck area
- a headache
- Slight drop in blood pressure
- Reddening of the mucous membranes and outer skin all over the body
A blood count test - if this is done - would reveal moderately increased signs of inflammation and, in an advanced stage, detect a loss of blood platelets.
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Course of disease
As with all infections, the course of the disease begins with an incubation phase in which the pathogens can multiply in the body without causing symptoms. In the case of Ebola, this usually takes seven to nine days. This usually leads to conjunctivitis of the eye and reddening of the oral mucous membranes. In addition, in this phase the fever begins with temperatures of over 40 degrees Celsius. Typically, this fever worsens and declines over the next ten to twelve days.
After the initial symptoms, there is a loss of platelets, diarrhea, reddening of the skin and inflammation of the liver. Shortly afterwards, the clinical picture is then completed by the heavy bleeding into organs and the skin, the so-called hemorrhages.
After the bleeding occurs, the fever subsides again and the sick person either survived the disease or previously died as a result of the severe blood loss, which leads to multiple organ failure.
What are the long-term consequences of an Ebola virus infection?
The consequences of the disease depend on the stage at which the therapy could be started and how bad the course of the disease was for the patient. From almost complete regeneration to restricted organ functions, everything is possible.
The advantage of a previous Ebola infection is that after the illness, people have antibodies that protect them from being infected again with an Ebola subtype, so that there is no risk of developing the same Ebola hemorrhagic fever again.
What is the probability of survival?
The probability of survival from an Ebola infection depends on several factors. In the previous outbreak areas, however, it has never exceeded 50%. Factors that can improve the likelihood are on the one hand a good immune system of the sick person, a diagnosis as early as possible, as well as good medical care and care for the sick person.
An epidemic in Western countries is estimated to have a survival rate of over 50%. In patients who were able to benefit from the best possible medical care and early therapeutic measures, the 2014 outbreak even managed to reduce the death rate to around 35%.
A specific vaccination against Ebola is currently not available in Germany. Only immunization against the yellow fever virus is permitted. Further vaccines are currently still in the development or testing phase.
Since there is currently no vaccination, people with symptoms should seek medical help as soon as possible and be quarantined to prevent the virus from spreading. People who have been connected to the sick person should also be kept an eye on.
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In which countries did Ebola break out?
The Ebola outbreaks have so far been mainly limited to central Africa and one outbreak on the Ivory Coast in West Africa in 1994.
In Central Africa, the first known outbreak occurred in 1976 in the Democratic Republic of the Congo and simultaneously in Sudan, which is northwest of the Democratic Republic of the Congo.
Ebola outbreaks have also occurred in Gabon, Uganda, Kenya and Angola.
The latest outbreak from 2014, however, also occurred on the west coast of Africa in the triangle between Guinea, Sierra Leone and Liberia.