Ebola Virus Disease

Ebola viruses are contagious, lethal viruses that are the causative agents of rare Ebola virus disease. Ebola virus disease, once known as Ebola hemorrhagic fever, can cause oozing from venipuncture sites, melena, hematochezia, and hematemesis. However, these manifestations are seen less than 50% of the time. Nonspecific symptoms, including fever, malaise, headache, and myalgias, are common initial symptoms. Diarrhea, nausea, and vomiting begin a few days later and can be severe.

The disease can quickly progress to multiorgan system failure, leading to shock and death. The overall case-fatality rate is about 40% to 50%. The main variables impacting survival rate are early disease identification and access to healthcare for patient stabilization and supportive medical care, differences in health status (such as nutrition and coinfections), genetic differences, and patient attitudes surrounding seeking medical treatment.

Highly transmissible, it can cause large outbreaks, epidemics, and pandemics. Despite outbreak control efforts, the Western African epidemic from 2013 to 2016 affected several countries outside continental Africa. An epidemic can have a devastating global impact on healthcare, the economy, and society. Treatment is mainly supportive; investigational therapies continue to be researched.

Ebola viruses, filamentous viruses with a characteristic twisted thread shape belonging to the Filoviridae family, were discovered in The Democratic Republic of Congo in 1976. Filoviridae are negative-strand RNA viruses and derive their name from the Latin word "filum," meaning thread. This viral family most commonly infects humans and primates and is thought to use fruit bats of the Pteropodidae family as a natural reservoir.

Due to the high transmissibility and lethality of Ebola viruses, high clinical suspicion and early diagnosis are vital to reduce mortality and the risk of an Ebola outbreak. Improved diagnostics, therapeutics, and vaccines have become available in the last few years, improving survival and decreasing the potential for spread. Adequate Infection Prevention and Control (IPC) measures must be implemented rapidly to prevent spread in healthcare facilities. Urgent reporting to Public Health allows contact tracing, surveillance, and other public health measures to be promptly implemented in the community.

To reduce the risks of Ebola epidemics and the potential misuse of the virus as an agent of bioterrorism, research is ongoing to further develop diagnostic tests, therapeutics, and vaccines.