Ebola virus disease (EVD), formerly known as Ebola hemorrhagic fever, is a severe, often fatal illness affecting humans and other primates.
How long this virus has existed is unknown, but we do know that it is carried by animals, such as fruit bats and other mammals.
Outbreaks in humans are thought to be caused by animal-to-human transmission after people consume or come into contact with animals harboring the virus.
Interestingly, the virus is known to survive several weeks in semen, but we do not know if that is a definite mode of transmission.
Controlling this virus in a country with good public health, trust in medical services, non-traditional practices and rule of law was thought to be relatively straightforward.
However, recent events in the USA and Spain have now shown that this is not the case and that there may be significant risk during and after the removal of complicated personal protective equipment (PPE).
On the other hand, both Nigeria and Senegal contained the virus and prevented onward transmission in their countries.
The spread within Africa could be down to a lack of early political involvement, public health dysfunction and lack of trust (understandably) in poorly functioning health systems, in some cases with workers or burial teams reportedly not getting paid on time.
There are other hemorrhagic (bleeding) viruses. These include Marburg, Lassa, Crimean-Congo, Argentine, Bolivian, Brazilian and more than 10 others.
The Marburg and Ebola viruses are the most alike, both being string-like (filamentous) and relatively large.
The virus is transmitted to people from wild animals (such as fruit bats, porcupines and non-human primates) and then spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.
Healthcare workers can become infected with Ebola through contact with blood or mucus, hence the need for basic precautions, such as gloves, masks, goggles, boots and, where available, bio-suits.
Infection can occur after removal of PPE if instructions are not followed to the letter.
Relatives become infected with the virus through caring for patients and becoming directly exposed to blood or mucus.
In many traditional African funeral practices, it is customary to wash and clean the dead body, which increases the risk for infection.
Non-medically trained nuns also spread the infection by using unsterilized needles on patients.
The virus has a predilection for Africa. The first EVD outbreaks occurred in remote villages in Central Africa, near tropical rainforests. The 2014–2016 outbreak in West Africa was the largest and most complex Ebola outbreak since the virus was first discovered in 1976. There were more cases and deaths in this outbreak than all others combined. It also spread between countries, starting in Guinea then moving across land borders to Sierra Leone and Liberia
Governments have now decided on airport screening of passengers from affected areas.
The symptoms of Ebola virus disease usually start five to seven days after becoming infected, but this can vary to between two to 21 days after becoming infected. A person infected with Ebola cannot spread the disease until they develop symptoms.
The symptoms are non-specific and include headache, joint and muscle pains, sore throat and muscle weakness. This is then followed by diarrhea, vomiting, fever, rash and stomach cramps.
Internal bleeding quickly follows, accompanied by bleeding from the ears, eyes nose or mouth.
Ebola virus disease is fatal in 50 to 90% of cases.
We know that Ebola spreads by contact with infected blood or mucus. To date we do not know if the virus can be air-borne, but fortunately we think it is not.
To avoid Ebola, do not travel to an outbreak area when it can be avoided.
Use basic hygiene precautions at all times, such as hand washing with soap and water after contact with cases or suspected cases.
Health care workers and relatives need to take specific precautions.
If you are infected, you need to be isolated from other non-medical people.
If you have had exposure as a health care worker, a self-quarantine of 21 days with daily temperature measurements now seems to be a sensible precaution and, in some areas, such as New York, it will be imposed.
It can be difficult to clinically distinguish EVD from other infectious diseases such as malaria, typhoid fever and meningitis. Confirmation that symptoms are caused by Ebola virus infection are made using the following diagnostic methods:
The test will not be positive before symptoms occur, which is usually on day three of the infection.
There are no medicines that are effective against this virus, so doctors are advised to treat the symptoms and treatment of specific symptoms improves survival.
Patients with Ebola need their fluid levels managed by medical staff – rehydration with oral or intravenous fluids -.
There is as yet no proven treatment available for Ebola virus disease. However, a range of potential treatments including blood products, immune therapies and drug therapies are currently being evaluated.
In the ongoing 2018-2019 Ebola outbreak in DRC, the first ever multi drug randomized control trial is being conducted to evaluate the effectiveness and safety of drugs used in the treatment of Ebola patients under an ethical framework developed in consultation with experts in the field and the DRC.