The Fatality of Ebola Virus Disease Outbreaks

Introduction

Ebola virus disease mainly about a zoonotic disease caused by Genus Ebola virus infection. It is an epidemic disease and commonly causes fatality not only among the humans infected but also among the animals like chimpanzees, monkeys and gorillas. The Ebola virus commonly infect people who lived in Guinea, Liberia, Sierra and Leone. This disease was first discovered in 1976 where there are two cases of fatal haemorrhagic fever happened in different parts of Central Africa which are near the village at Ebola river and around South Sudan. There are several types of Ebola virus, such as Zaire Ebola virus, Sudan Ebolavirus, Tai Forest Ebola virus, Bundibugyo Ebola virus, Reston virus and Bombali Ebola virus. Within these types of several viruses, only few of them can cause disease which are Zaire, Sudan, Tai Forest and Bundibugyo viruses. (Centers for Disease Control and Prevention,2018). Meanwhile, Reston virus can cause disease in nonhuman primates and pigs while Bombali cannot be determined whether it can cause disease in either animals or people.

As mentioned above, there are two cases of fatal Ebola virus disease discovered in 1976 at Ebola River at Central Africa and at South Sudan. Since then, the virus has been infecting people from time to time, lead to outbreaks in several African countries. The scientists do not know on what causing Ebola virus disease. However, based on the nature of similar viruses, they believe the virus is by animal transmission, with bats commonly function as vector. The bats which carry the virus can transmit it to other humans and animals as hosts such as chimpanzees, monkeys as well as gorillas. The human can be infected from the animals usually because of the person’s in contact with another infected person’s body fluid or with the humans which die due to the Ebola virus disease. Moreover, if the person has a broken skin, the virus can easily penetrate into the body through skin. Plus, the virus also can be transmitted by sexual transmission. (World Health Organization,2018)

Structure

The shape generally in long cylindrical and tubular shape and it can be appeared as a “U-shaped” and circular. It has approximately 80 nm in diameter and 970 nm long. The virus contains viral envelope, matrix, and nucleocapsid components. They have a virally encoded glycoprotein (GP) projecting as 7-10 nm long spikes from its lipid bilayer surface. Glycoproteins are proteins that contain carbohydrate chains (glycans) covalently attached to their polypeptide side chains. The glycoprotein GP is the sole resident of the Ebola virus surface and is the only surface proteins that accounted for both attaching to and entering the new host cells. The outer viral envelope of the virion is derived by budding from domains of host cell membrane into which the GP spikes have been inserted during their biosynthesis. (Sagar Aryal,2018) Ebola virus has a single stranded RNA genome which encoding eight structural proteins which are nucleoprotein, virion protein, polymerase protein, transmembrane glycoprotein and soluble glycoprotein. (Daniel R. Beniac & Timothy F. Booth, 2017).

Symptoms

Several signs can be observed from the patients having Ebola virus. For instance, at the early stage of disease, the patients will undergo fever, severe headache, muscle pain, tiredness, fatigue, vomiting, diarrhea as well as abdominal cramp and in severe condition, haemorrhage. These symptoms can be occured anywhere in 2 to 21 days after being infected. However, there are also common illness which can have these same symptoms like malaria and influenza. (Centers for Disease Control and Prevention, 2018).

Inside the cell, the protein virus which is glycoprotein will disrupt the cell structure. The cells will have problems to adhere to each other and to the extracellular matrix. Within the blood vessel, the penetration of the virus causing the blood vessel to disrupt which resulting in leaky and haemorrhagic blood vessels. Plus, Ebola virus also affect the liver cells. The liver’s ability to clear toxin out of body was reduced. Besides, the virus also affect the immune system which resulting in increase of area of infection. This will cause more organ failure which lead to fever, diarrhea, vomiting and resulting in increase of loss of electrolytes, blood plasma and fluid. (Ilana Kelsey, 2014)

Transmission of Disease

During the first outbreaks of Ebola virus disease, it is found that the infection was transmitted and spread easily due to the uses of needles and syringe. For instance, in the first outbreak at Republic of Congo, the nurses reported that they use five syringes for 300 to 600 patients per day. In 1989, scientists discovered the Reston Ebola virus and confirmed that the infection spread by droplets’ transmission among the monkeys, however, it is not proven that the air-borne transmission can be a significant factor among the humans. After the outbreak of Cote d’Ivoire Ebola virus outbreak, the health practitioners had been aware of the usage of contaminated needles and syringe by introducing the disposable needles. They also decrease the transmission of disease by using face masks, gloves and gown of healthcare personnel. By 1995, Zaire Ebola virus outbreak, the public health community educate the community on how the disease transmit and the healthcare practitioners also has been provided of the necessary equipment. During 2014-2016, Ebola outbreak has been occured in West Africa, mainly transmitted among the family members which may be because there is direct contact with the dead person suffered from Ebola virus disease. (Centers for Disease Control and Prevention, 2018)

Ebola virus has a genetic material called DNA which used for assembling new viral particles. However, in order to form new viral cells, the virus cannot replicate within itself and it need another host cell to reproduce. Thus, it must enter the cell membrane of the host cell which protects the cell from its environment. The penetration of virus to the cells will trigger the cells to engulf the virus. The virus takes opportunity of the non-specific engulfing process which called “macropinocytosis”, which allows the viral to be entered into the host cell via wave-like motion of the cell membrane. (Ilana Kelsey, 2014)

Diagnosis

Diagnosis of Ebola virus disease can be difficult because at early stage, the symptoms are similar to the other common diseases like malaria and influenza such as fever, fatigue and vomiting. Thus, the Ebola virus disease can be confirmed by combining to the other symptoms like the possible exposure to the Ebola virus disease within the 21 days. The exposure may be due to a person’s in contact with the other person’s blood or body fluid infected by the Ebola virus disease. The patients also may touch the objects which contaminated to the blood or body fluid of the person having the disease or with the person who died from Ebola virus disease. In addition, the patients also may eat the infected fruits bite by the infected bats and last but not least, the person may sexually infect with the semen by an infected man. However, if the person has showed the early sign and the possible exposure, they should be isolated from other persons to prevent from being infected. The patients’ samples of blood should be collected and recorded. If the laboratory test shows positive results, thus, the disease was confirmed. (Centers for Disease Control and Prevention, 2018)

Treatment

Currently, there is no vaccines available for Ebola virus disease. Thus, the doctor only treated the patients by providing sufficient fluids and electrolyte by intravenous. The patients also will be given the oxygen therapy to maintain the patients’ oxygen status and blood pressure. They also will be treated for the other infections. However, in October 2014, the World Health Organization licensed two Ebola virus vaccines which are cAd3-ZEBOV and rVSV-ZEBOV. cAd3-ZEBOV contained Ebola virus gene in it by using chimpanzee-derived adenovirus as a vector which has been developed by GlaxoSmithKline in collaboration with the United States National Institute of Allergy and Infectious Diseases (NIH). Meanwhile, rVSV-ZEBOV vaccines uses weakened virus which is one of them contained Ebola virus. Other than that, the patients also can be treated with antiviral therapies such as ZMapp which consist of three chimeric monoclonal antibodies. The patients also will be treated with two antiviral drugs, favipiravir and remdesivir. However, these therapies are still under experimental settings and clinical trials. (European Centre for Disease Prevention and Control)

Prevention

If Ebola virus diseases occur in Malaysia, we must take some precautions in order to prevent the disease from being spread rapidly. First and foremost, the Ebola patients must be isolated from the community to prevent them from infecting others because the community do not have protective attire. We also must avoid ourselves from come in contact with the blood and body fluids or even the patients’ equipment. (Centers for Disease Control and Prevention,2018). Besides, the healthcare practitioners also must wear protective clothing such as masks, gloves and goggles in order to avoid themselves from being infected whenever the Ebola patients came to the hospital. Furthermore, the hospital also must use a the sterilize equipment such as needle and syringe to prevent the disease from being spread and the equipment should not be shared among the patients. During the outbreak, we are also must be prohibited from getting too close or in contact with the chimpanzees, monkeys and bats because they may be had been infected. (European Centre for Disease Prevention and Control).