This paper will provide a comprehensive overview of Ebola virus disease with emphasis on the clinical aspects: etiology, pathophysiology, clinical manifestations, diagnosis, and treatment.
Ebola virus disease has been identified as one of the most fatal diseases in humans. This disease was first identified in 1976, and it used to be called Ebola hemorrhagic fever since its initial outbreaks in Sudan and Democratic Republic of Congo near Ebola River, simultaneously (WHO, 2015). Since then, there have been perennial outbreaks in Central Africa, but the March 2014 outbreak in West Africa has turned out to be the most catastrophic outbreaks in which over 4,492 people have died from the disease.
Table of Contents
Introduction
Etiology
Pathophysiology
Clinical Manifestations
Treatment
Conclusion
References
Introduction
Ebola virus disease has been identified as one of the most fatal diseases in humans. This disease was first identified in 1976, and it used to be called Ebola hemorrhagic fever since its initial outbreaks in Sudan and Democratic Republic of Congo near Ebola River, simultaneously (WHO, 2015). Since then, there have been perennial outbreaks in Central Africa, but the March 2014 outbreak in West Africa has turned out to be the most catastrophic outbreaks in which over 4,492 people have died from the disease (King et al., 2015). Therefore, this paper will provide a comprehensive overview of Ebola virus disease with emphasis on the clinical aspects: etiology, pathophysiology, clinical manifestations, diagnosis, and treatment.
Etiology
Etiology of Ebola is associated to the Ebola virus which belongs to Filoviridae virus family. This virus family comprises of three main genera: Marburgvirus, Cuevavirus and Ebolavirus. Therefore, Ebola disease is caused by viruses in the genus Ebolavirus. This genus comprises of five species: Bundibugyo ebolavirus, Zaire ebolavisus, Reston ebolavirus, Sudan ebolavirus, and Tai Forest ebolavirus. These species are the etiological causes of Ebola virus disease among humans. However, their pathogenicity differs significantly with Sudan ebolavirus, Zaire ebolavirus and Bundibugyo ebolavirus being the most virulent. These three species have been identified to be responsible for periodic outbreaks in Central and West Africa. For instance, Zaire ebolavirus has been found to be responsible for the 2014 Ebola outbreak in West Africa (WHO, 2015).
Pathophysiology
Ebola virus disease is believed to be transmitted to humans by the fruit bats which act as natural hosts for Ebola virus. However, it is worth noting that only bat species belonging to the Pteropodidae family have been linked with Ebola transmission to humans and wildlife including porcupines, monkeys, gorillas, chimpanzees, and forest antelopes (WHO, 2015). The virus is transmitted to humans through close contact with bodily fluids including blood and secretions from infected animals. Transmission among humans occurs through direct contact with infected people, in which the virus enters the body through mucous membranes, gastrointestinal lining or broken skin (King et al., 2015). It also occurs when healthy people get into contact with contaminated materials such as clothing or surfaces. After infection, the virus undergoes rapid multiplication in which its proteins are encoded into secretory glycoprotein. This secretory glycoprotein binds g-receptors of the neutrophils, and this binding has been found to inhibit the activation of neutrophils which occurs as an immunologic response. Another form of glycoprotein binds with endothelial cells, and cause destruction to the endothelium through causing intravascular coagulation (Côté et al., 2011).
Clinical Manifestations
Owing to the pathophysiology of the disease which inhibits immunologic response mediated by neutrophils and the destruction of endothelial cells, infection with Ebola virus is manifested by lymphopenia during the early stages of infection and hemorrhagic manifestations, respectively (King et al., 2015). For instance, hunters in Guinea where the outbreak was first reported might have acquired the infection from ingestion of game meat from an infected animal such as an antelope. These patients showed clinical manifestations of the disease at different stages of disease development.
The early signs and symptoms of Ebola virus disease in the patients included fever, maculopapular rash and pharyngitis. On the other hand, late manifestations include bleeding from mucus membranes, pulmonary edema, myocarditis, hypotension, anuria, tachypnea, and coma. It is also worth noting that patients who have survived Ebola virus disease show some manifestations such as headache, bulimia, myalgias, amenorrhea, fatigue, unilateral orchitis, tinnitus, and suppurative parotitis (King et al., 2015).
Currently, a number of diagnostic techniques have been designed. These techniques include: blood tests such as creatinine test, liver enzymes test, pH, and blood urea nitrogen test, and viral isolation using RT-PCR assay and tissue culture. Serological tests such as ELISA are also done to test the presence of the antigen or immunoglobulin antibodies generated by the immune system after the viral infection. In addition, immunochemical tests and electron microscopy are useful to identify the virus in postmortem skin (King et al., 2015).
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- Citation du texte
- Patrick Kimuyu (Auteur), 2016, Ebola. A Comprehensive Overview, Munich, GRIN Verlag, https://www.grin.com/document/383558
