Ebola Virus Disease – An Emergent Public Health Threat of th the Late 20 Century

Abstract

Ebola virus disease is one of the new emerged infectious diseases of the late 20 century. It is a severe, often fatal illness in humans marked by severe bleeding (haemorrhage), organ failure and with fatality rates of between 50% and 90%. Ebola virus is native to Africa and is previously characterized by outbreaks in isolated and remote communities in the rainforest. The 2014 Ebola outbreak is reported in four West African countries namely, Guinea, Liberia, Sierra Leone, and Nigeria. Ebola virus disease (EVD) is caused by members of the genus Ebolavirus with five (5) recognized species namely Zaire Ebolavirus, Sudan Ebolavirus, Ivory Coast Ebolavirus, Reston Ebolavirus, and Bundibugyo Ebolavirus, all of which belongs to the family, Filoviridae. The transmission of Ebola virus involve two major steps; firstly from suspected natural hosts or reservoir believed to be fruit bats to animals in the wild and secondly, from animals in the wild to humans. Human-to-human transmission occurs through direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids (vomit, faeces, urine, breast milk, semen, and sweat) of infected persons. Although the clinical course of infection with an incubation period of between 2 to 21 days is well known, the specific mechanisms underlying the pathogenicity of Ebola virus have not been clearly understood. Several lines of evidence suggest that the viral glycoprotein (GP) plays a key role in the manifestation of Ebola virus infection. EVD can be diagnosed in the laboratory by reverse transcriptase polymerase chain reaction (RT-PCR) assay, antibody-capture enzyme-linked immunosorbent assay (ELISA), antigen detection tests, serum neutralization tests and virus isolation by cell culture. Currently, there are no approved drugs or vaccines to treat or prevent Ebola. Treatment consists of supportive therapy to maintain electrolyte balance. However experimental vaccines and antiviral drugs are undergoing development and clinical trials. The potential treatment of Ebola Haemorrhagic fever patients with passive immune therapy (i.e. blood transfusion) from convalescent patients is being explored. Prevention of EVD consists of avoiding close contact with gravely ill patients, improvement of personal hygiene especially hand hygiene, strict barrier nursing techniques including the use of personal protective equipment and safe burial of the dead.