Ebola is an infectious disease easily spread from human to human. It as one of the Hemorrhagic Fevers type. Symptoms are invariably severe with a high death rate.
Ebola is a RNA virus of the Filovirus family, which also includes the Marburg virus.
Ebola is also known as Ebola Virus disease (EBD) or Ebola Hemorrhagic Fever (EHF)
Various
vaccines have been in development for the past decade.
A recombinant vaccine, comprised of a live attenuated viral-vector, modifed with an Ebola virus gene (rVSV-ZEBOV, "Ervebo")
was authorized for use by the WHO and the FDA in 2019.
A recombinant adenovirus viral-vector vaccine and booster (Ad26.ZEBOV, "Zabdeno" and MVA-BN-Filo,"Mvabea")
was authorized by the European Medicines Agency in 2020.
The effectiveness, safety, and duration of protection are still being studied.
Initial infection in humans is believed to come from contact with monkeys or bats.
Ebola is then spread from human to human by contact with infected bodily fluids such as
blood, urine, saliva, mucus etc. through the nose, mouth, eyes, and open wounds.
It can also be spread by contact with the bodies of those who have died of the disease.
Symptoms include high fever, sore throat, headache, vomiting, diarrhea,
joint and muscle pain, and often a widespread rash of small red bumps.
The ability of the blood to form clots is impaired leading to both internal and external bleeding and bruising.
Prolonged vomiting and diarrhea may lead to severe dehydration and death.
Incubation, the time from exposure to the virus until onset of symptoms, is usually 4 to 10 days (range 2 to 21 days).
Recovery usually begins 7 to 14 days after the onset of symptoms.
When death occurs, it is usually usually 5 to 15 days after the onset of symptoms.
The virus may persist in bodily fluids from an infected person for several days, and persists in the bodies of those who have died. However, Ebola is quickly inactivated in open air.
Diagnosis is made on the basis of symptoms, and history of contact with those already infected.
However, early symptoms are similar to many other viral diseases.
Blood tests show abnormalities in blood cells and liver function.
The virus can be grown in a laboratry from specimens of bodily fluids.
Antibodies can be detected in the blood within a few days of initial symptoms.
Due to bleeding and dehydration, almost any body system can be affected.
Treatment is directed at maintaining hydration, and transfusions of blood cells to correct clotting problems. As of 2020, no specific anti-viral/anti-ebola medications are available.
Prevention comprises strict adherence to standard infection control procedures, isolation of infected patients,
and use of personal protective equipment.
Vaccines have been devloped but not yet in widespread use.
Those who survive often experience prolonged joint and muscle pain, fatigue, weakness, poor appetite and continuing weight loss, and problems with vision and hearing.
Death occurs in 25% to 75% of patients, depending on the availability of treatment.
Outbreaks occur almost yearly with a few dozen to a few hundred deaths.
The West African epidemic (2013-2016) resulted in over 10,000 deaths.
The Kivu epidemic (2018-) in the Democratic Republic of Congo has resulted in over 2,000 deaths so far, and is continuing into mid-2020.
Ebola occurs throughout Africa except those countries bordering the Mediterranean. Outbreaks have been identified in such countries as Sudan, Democratic Republic of Congo, Uganda, Guinea, Liberia, and Sierra Leone.