Ebola’s Fatal Hemorrhagic Fever from Discovery to Vaccine

Abstract

The Ebola Virus (EBOV) causes a hemorrhagic fever that is distinguished by a sudden onset of intense headaches, fever and severe hemorrhages which can be fatal in less than a week. The largest Ebola outbreak to date is currently underway, with 28.488 confirmed, probable and suspected cases reported, 15.239 laboratory confirmed cases and 11.297 fatalities as of October 11th, 2015. Most of the cases have occurred in Sierra Leone, Liberia and Guinea. The Ebola virus genus has five species: Zaire, Sudan, Tai Forest, Reston and Bundibugyo. The Zaire virus has caused ten epidemics since its identification in 1976, with a mortality rate of 57%-88%. Fruit bats appear to be the natural reservoir of EBOV, while human to human transmission is spread through direct contact of infected bodily fluids; patients only acquire the ability to infect others when symptomatic. Once inside the host, EBOV infects immune system cells directly and begins to replicate inside them while severely compromising it. Recent evidence shows EBOV alters cytokine expression while expressing its own viral proteins causing significant lymphopenia and lymphapoptosis, as well as endothelial damage. Massive hemorrhages throughout the body are one of the cardinal points of EBOV infection; however, it is not as present in patients as it is believed. The current outbreak has affected countries where sanitation is inadequate, resulting in the inability to control its spread. This review aims to give a broad spectrum of the current findings in several fields to better comprehend Ebola´s fatal Hemorrhagic Fever.