Abbreviations

۱٫ Introduction

۲٫ Ebola virus biology

۳٫ Pathogenesis

۴٫ Epidemiology and demographics

۵٫ Transmission

۶٫ Clinical manifestations

۷٫ Diagnosis

۸٫ Therapeutic strategies for EBOV infection

۹٫ Prevention and control of EBOV disease

۱۰٫ Conclusions

Appendix A. Supplementary data

Funding

References

Abstract

The genus Ebolavirus from the family Filoviridae is composed of five species including Sudan ebolavirus, Reston ebolavirus, Bundibugyo ebolavirus, Taï Forest ebolavirus, and Ebola virus (previously known as Zaire ebolavirus). These viruses have a large non-segmented, negative-strand RNA of approximately 19 kb that encodes for glycoproteins (i.e., GP, sGP, ssGP), nucleoproteins, virion proteins (i.e., VP 24, 30,40) and an RNA dependent RNA polymerase. These viruses have become a global health concern because of mortality, their rapid dissemination, new outbreaks in West-Africa, and the emergence of a new condition known as “Post-Ebola virus disease syndrome” that resembles inflammatory and autoimmune conditions such as rheumatoid arthritis, systemic lupus erythematosus and spondyloarthritis with uveitis. However, there are many gaps in the understanding of the mechanisms that may induce the development of such autoimmune-like syndromes. Some of these mechanisms may include a high formation of neutrophil extracellular traps, an uncontrolled “cytokine storm”, and the possible formation of auto-antibodies. The likely appearance of autoimmune phenomena in Ebola survivors suppose a new challenge in the management and control of this disease and opens a new field of research in a special subgroup of patients. Herein, the molecular biology, pathogenesis, clinical manifestations, and treatment of Ebola virus disease are reviewed and some strategies for control of disease are discussed.

Introduction

Ebola viruses (EBOVs) belong to the Filoviridae family and are characterized by a negative stranded RNA structure [1]. It should be noted that the nomenclature and disease classification of the filoviruses has been a subject of intense discussion as summarized elsewhere [2]. Of the various filoviruses, EBOV has garnered worldwide attention due to the rapidity of acute hemorrhagic disease and the highly infectious nature of the virus. Discovered during the first documented outbreak of EBOV disease in the town of Yambuku in the Democratic Republic of Congo (DRC) in 1976, these viruses have caused outbreaks of variable magnitude in several west and equatorial African countries. In the most recent outbreak in West Africa between 2013 and 2016, about 28,000 cases were confirmed and up to 11,000 deaths were reported, thus demonstrating the high mortality of this condition [3].

These viruses present human-to-human transmission secondary to contact with contaminated fluids which enables their spread in povertystricken areas. The African fruit bat (i.e., Rousettus aegyptiacus) is considered the natural reservoir for Ebolavirus and these bats can transmit the virus to Apes, monkeys and species such as antelopes that are resident in the forested areas. Humans living in the forested areas, eating such infected animals, and the handling of Ebolavirus infected dead bodies are considered risk factors associated with cultural and religious behaviors that hinder the control of outbreaks in these regions [4].