Ebola Virus Essay Example
Ebola Virus Disease (EVD) also commonly known as hemorrhagic fever virus according to the World Health Organization, is a virus that causes problems with how blood clots. This problematic blood clotting leads to internal bleeding throughout the body. Ebola virus(EBOV) comes from the genus family of Filoviridae. Some other common viruses from the filoviridae family include Marburg Virus and Cuevavirus. All three viruses include negative single-stranded RNA which has a very unique structure. Ebola virus virion nucleic acid is a negative-stranded RNA(Regnery, 1980). Like many viruses, Ebola has a helical capsid (Noda, 2010). Ebola is unique as its nucleocapsid has the ability to change into many other different shapes. The lengths of these differ greatly, resulting in a certain length having to be met before they become infectious. The average length must be approximately 970 nm with a diameter of 80nm (Huang, 2002). The RNA genome of Ebola (EBOV) is encapsulated in a nucleoprotein which further forms a ribonucleoprotein (RNP).
Ebola was first discovered in 1976 when two major Ebola breakouts occurred in Central Africa. The first Ebola outbreak originated in a small village off the coast of the Ebola River in the Democratic Republic of Congo, hence giving the virus its name. The next outbreak occurred about 500 miles north of that village in South Sudan. At first, scientists thought the viruses in both of these countries were genetically identical, however, later research discovered that the outbreaks were caused by two genetically different viruses. Due to the relative ease of the Ebola virus’s ability to mutate as a result of its nucleocapsids ability to easily change shape. This is due to how easily the Ebola viruses can mutate thanks to the nucleocapsid’s ability to change shape easily. These two different strands in the two outbreaks were Zaire Ebolavirus and Sudan Ebolavirus meaning both viruses had to come from two different sources. Since the first Ebola census was taken in 2014, there have been a total of 26 Ebola outbreaks globally since its discovery. So far the largest Ebola outbreak occurred in West Africa in 2014 and lasted until the end of 2016. This certain mutation spread to many other countries across Europe, Africa, and North America. Since the discovery of the Ebola virus, 24 of the 26 outbreaks and cases have primarily stayed in Africa.
After the discovery of Ebola thousands of scientists rushed to identify the source, commonly referred to as a reservoir. After immense studying of humans, animals, plants, and insects, scientists came to the conclusion that the Ebola virus was mainly spread across Africa by African fruit bats of the Pteropodidae family. Although it has not been scientifically proven scientists believe that the African fruit bats may have also been the original natural reservoir. Ebola is spread through droplet or contact transmission, meaning it can be spread through blood, saliva, secretions, bodily fluids, and infected hosts. This virus can also be spread by direct contact through mucous membranes or broken skin from host to host. It can also be transmitted through an intermediate host which can support the virus for a short period of time. For example, blood, stool, and emesis left on dry surfaces containing the virus can survive for several days and still be infectious. The virus is also able to stay in the blood and bodies of deceased hosts for long periods of time after death. Ebola virus most commonly infects humans and nonhuman primates (ex. monkeys, gorillas, or chimpanzees). The first outbreak of Ebola was the fault of contaminated needles and syringes in the Democratic Republic of Congo. In a history report from the Centers for Disease Control and Prevention(CDC), it said that nurses in the Yambuku Hospital in Congo were only using 4 to 5 needles and syringes a day for the entirety of one shift for 300-600 patients. This wasn’t an issue with ignorance on the hospital’s nurses part but it was due to a lack of medical supplies across the Republic. The infected blood left on needles contaminated the needles and syringes and transmitted the infection to every patient that used that needle. This amplified the virus quickly and turned a few cases into a global pandemic within months.
For the Ebola virus to successfully enter the cell it only has to complete one essential step. The virus needs a surface of glycoprotein and a unique particle structure to enter. When the Ebola virus enters the body it binds with the cell’s surface proteins and internalizes into the cell of the host. From there it moves through the endosomal vesicles to intracellular acidic compartments. This is where the host’s enzymes process the glycoproteins, which then interact with the intracellular receptors (Sakurai). If all of these circumstances are met under the right conditions then the viral and endosomal membranes will fuse completing the host cell entry. Once Ebola enters the body the virus starts attacking our endothelial cells. These cells are what make up a thin layer of waterproof mesh that lines our blood vessels. The virus starts by attacking the endothelial cells in capillaries which are the smaller blood vessels of the body located in the mouth, eyes, nose, and lining of the stomach. As the virus replicates the waterproof mesh formed by our endothelial cells breaks apart causing blood and fluid to leak out. Resulting in bloody eyes, nose bleeds, and bloody stool. Due to all the leakage, the host becomes extremely dehydrated. Ebola then goes on to weakening the endothelial cells in larger veins and arteries. The mesh of endothelial cells in larger veins and arteries is surrounded by a layer of vascular muscle. This muscle layer is able to stop the blood and fluid from leaking when Ebola attacks, but the endothelial layer is still damaged causing the body’s muscles to lose their tone. When muscles weaken or lose their tone the body’s blood vessels have to work harder to pump blood to major organs. This is why many Ebola hosts’ hearts, livers, lungs, and brains start failing and shutting down.
Ebola virus has a fatality rate of 25-90% with about a 50% average depending on the outbreak. In addition to the loss of human life, this devastating virus has major impacts on the country’s economy. When an Ebola case is discovered it becomes the countries main priority to isolate and prevent the spread of the virus further. The 2014-2016 Ebola outbreak alone cost the countries involved an estimated total of $2.8 billion. This was due to several main impacts that affect a country’s economy when they experience an outbreak or pandemic. The major impact is a decrease in trade, transportation, and tourism. People are not going to want to travel to a country that is experiencing a deadly pandemic, no one wants to be put themselves at risk of contracting the virus. The country will sometimes also put a travel ban, trade ban, or quarantine restrictions out for a period of time to prevent further transmission to other countries. Since Ebola was transmittable from human to human contact and from contaminated objects or surfaces countries did put out such restrictions. For the majority, of countries, this can be devastating for the economy because trade is a major source of income. During the 2014-2016 outbreak, Sierra Leone, a country in Africa, declared a three lockdown to try to organize and decrease the spread. Additionally, they set curfews and quarantines that lasted months for high-risk areas in the country. A report from the African Brief Economy said that 43% of Sierra Leone’s national income came from informal cross-border trade (Mercy Corps). Many countries also depend on tourism economically. During outbreaks, borders close, and airlines stop coming in. It has shown that countries not just bordering but on the same continent see decreases in tourists as well during these times. Times can be very challenging and stressful when a country has to go through this. They have to deal with limited goods, limited funds, the threat of the unknown new virus, scared citizens, and trying to keep a country safe and in order. It is important for us to know that Ebola is not an airborne disease that you can get from walking around outside with bats. It has to come from a bodily fluid (saliva, blood, etc) of an infected host and find its way into a mucous membrane.
As of right now, there is no cure for the Ebola virus but drug treatments are in the works for supportive care. There are two drug treatments that were just recently approved by the U.S. Food and Drug Association(FDA). The first drug treatment, Inmazeb, was approved in October of 2020 and it consists of a combination of three monoclonal antibodies. Monoclonal antibodies are artificial antibodies made by scientists that are placed in the body to stop the virus from replicating without the host having to contract the virus first. The second treatment is Ebanga and it was approved in December of 2020. This drug consists of only a single monoclonal antibody. Both of the drugs are still in the controlled trial phases but have shown higher survival rates in every trial when patients were taking the drugs while infected. Still no vaccine has been created yet to cure the Ebola virus.
