Ebola virus infection

Initial stages of infection are nonspecific, which makes the differential diagnosis broad; therefore, clinical suspicion of the infection with prompt isolation is very important in the context of a history of exposure.

Management is centered around supportive care and infection control. The lack of any specific antiviral treatment or approved vaccine makes treatment difficult; however, several potential therapeutic agents are undergoing accelerated development, and clinical studies are either planned or ongoing.

Case fatality rates range from 25% to 90%, but the average rate was approximately 50% in most treatment centers in the 2014 outbreak in West Africa. Survivors often have prolonged ill health with significant disability.

The risk of sexual transmission from male survivors may persist for at least 12 months.

As there is the possibility of infected people traveling, all countries should have tested and practiced protocols ready for screening and managing patients.

A severe, often fatal, zoonotic infection caused by infection by a virus of the Filoviridae family (genus Ebolavirus). There are currently 5 known species: Zaire ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus, Bundibugyo ebolavirus, and Reston ebolavirus.[1]Centers for Disease Control and Prevention. About Ebola virus disease. February 2016. http://www.cdc.gov/ (last accessed 19 July 2017). http://www.cdc.gov/vhf/ebola/about.html  The Zaire ebolavirus is responsible for the outbreak that started in West Africa in 2014, the largest outbreak since the virus was first discovered in 1976.

The virus is thought to be initially acquired from infected animals such as bats and nonhuman primates, but has potential for human-to-human transmission. Transmission occurs by close contact with body fluids of infected patients. The incubation period after infection is 2 to 21 days (typically 3-12 days).[2]World Health Organization. Ebola virus disease fact sheet. February 2018 [internet publication]. http://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease  Incubation periods may be shorter in children.[3]WHO Ebola Response Team. Ebola virus disease among children in West Africa. N Engl J Med. 2015;372:1274-1277. http://www.nejm.org/doi/full/10.1056/NEJMc1415318 http://www.ncbi.nlm.nih.gov/pubmed/25806936?tool=bestpractice.com Patients are not considered infectious until they develop symptoms. Human infection carries a high case fatality rate depending on the Ebola virus species and quality of supportive care available.

Ebola virus infection is part of the group of conditions known as viral hemorrhagic fevers, and was formerly known as Ebola hemorrhagic fever.

BMJ Best Practice podcast: Ebola - medical guidance and lessons from West Africa with Dr Tom Fletcher