Ebola is an infectious and frequently fatal disease marked by fever and severe internal bleeding, spread through contact with infected body fluids by a filovirus (Ebola virus). It is named after a river in the Democratic Republic of Congo (previously Zaire), near which the disease was first observed in 1976.
Where is ebola usually found?
Ebola viruses are found in several African countries. Ebola was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, outbreaks have appeared sporadically in West and Central Africa [CDC]; with the diease known to have been caught in Sudan, Zaire, Gabon, Uganda, Republic of the Congo, Democratic republic of the Congo, Liberia, Sierra Leone, Nigeria, mali, United States, Senegal, Spain, United Kingdom [Wikipedia]
common is ebola?
There have been 33 Ebola outbreaks since 1976, but the 2014 outbreak in West Africa is by far the largest. The virus has infected thousands of people and killed more than half of them. It started in Guinea and spread to Sierra Leone, Liberia, and Nigeria. [WebMD]
How is ebola transmitted?
Because the natural reservoir host of Ebola viruses has not yet been identified, the way in which the virus first appears in a human at the start of an outbreak is unknown. However, scientists believe that the first patient becomes infected through contact with an infected animal. Person-to-person transmission follows and may lead to large numbers of affected people. In some past Ebola outbreaks, primates were also affected by Ebola and multiple spillover events occurred when people touched or ate infected primates. [CDC]
The virus can be spread to others through direct contact (through broken skin or mucous membranes in, for example, the eyes, nose, or mouth) with
- blood or body fluids (including but not limited to urine, saliva, sweat, feces, vomit, breast milk, and semen) of a person who is sick with or has died from Ebola,
- objects (like needles and syringes) that have been contaminated with body fluids from a person who is sick with Ebola or the body of a person who has died from Ebola,
- infected fruit bats or primates (apes and monkeys), and
- possibly from contact with semen from a man who has recovered from Ebola (for example, by having oral, vaginal, or anal sex)
Ebola is not spread through the air, by water, or in general, by food. However, in Africa, Ebola may be spread as a result of handling bushmeat (wild animals hunted for food) and contact with infected bats. There is no evidence that mosquitoes or other insects can transmit Ebola virus. Only a few species of mammals (e.g., humans, bats, monkeys, and apes) have shown the ability to become infected with and spread Ebola virus.
there a genetic / familial / hereditary factor?
No; the disease is caused by a virus.
is most at risk from ebola?
Anybody traveling to or through area where the disease is active; health workers are particluarly at risk. The tropical areas where the diease most often occurs means that perspiration is unavoidable, so any direct contact with anyone infected can result in infection.
What are the
symptoms of ebola?
Symptoms typically appear within five to 10 days of infection; early signs include [Mayo]:
- Severe headache
- Joint and muscle aches
Over time, symptoms become increasingly severe and may include:
- Nausea and vomiting
- Diarrhea (may be bloody)
- Red eyes
- Raised rash
- Chest pain and cough
- Stomach pain
- Severe weight loss
- Bleeding, usually from the eyes, and bruising (people near death may bleed from other orifices, such as ears, nose and rectum)
- Internal bleeding
When is it necessary
to contact a doctor?
Anyone who has been in an affected area, or in contact or near an infected person, who experiences any of the above symptoms, should seek medical advice immediately. Staff returning to the UK from disease areas were considered 'safe' if no fever had appeared - this proved to be a serious error. [BBC]
What are the long term
effects of ebola?
So far, there is little documented evidence about long-term effext, but individual accounts suggest that while it can take many months, most people who survive the disease will eventually expect a full recovery. However, effects such as body and joint aches, and fatigue are much the same as might be expected from any very serious viral infection. One survivor reported hair loss, body aches and insomnia in the months following her infection. [LiveScience]
What is the mortality
rate for ebola?
The fatality rate has varied with different outbreaks, but the average appears to be around 50%. Case fatality rates have varied from 25% to 90% in past outbreaks. [WHO]
How is ebola diagnosed?
Diagnosing Ebola in a person who has been infected for only a few days is difficult because the early symptoms, such as fever, are nonspecific to Ebola infection and often are seen in patients with more common diseases, such as malaria and typhoid fever.
However, a person should be isolated and public health authorities notified if they have the early symptoms of Ebola and have had contact with
- blood or body fluids from a person sick with or who has died from Ebola,
- objects that have been contaminated with the blood or body fluids of a person sick with or who has died from Ebola,
- infected fruit bats and primates (apes and monkeys), or
- semen from a man who has recovered from Ebola
Ebola virus is detected in blood only after onset of symptoms, most notably fever, which accompany the rise in circulating virus within the patient's body. It may take up to three days after symptoms start for the virus to reach detectable levels. [CDC]
Laboratory tests used in diagnosis include:
|Within a few days after
onset of symptoms:
- Antigen-capture enzyme-linked immunosorbent assay (ELISA) testing
- IgM ELISA
- Polymerase chain reaction (PCR)
- Virus isolation
|Later in disease course
or after recovery:
- Immunohistochemistry testing
- Virus isolation
there a treatment for ebola?
No specific vaccine or medicine (e.g., antiviral drug) is available for Ebola.
Symptomatic treatment of Ebola can significantly improve the chances of survival [CDC]:
- Providing intravenous fluids (IV) and balancing electrolytes (body salts).
- Maintaining oxygen status and blood pressure.
- Treating other infections if they occur.
Is there a
way to prevent infection?
There is no vaccine to prevent Ebola. People can avoid catching the disease by not traveling to areas where the virus is found. Health care workers can prevent infection by wearing preferably full body suit protection, but, as a minimum, masks, gloves, and goggles, whenever they come into contact with people who may have Ebola. [WebMD]
Is there an ebola
There are no proven vaccines for Ebola, to prevent individuals becoming infected.
However, progress is now being made, and trials, which would normally take years and decades, are being fast-tracked on a timescale of weeks and months. Experimental vaccines have been used in people who have gone on the survive; however, it is impossible to know what part (if any) the unproven medicines played in recovery.
Can ebola be controlled
The US Centers For Disease Control has issued Infection Prevention and Control Recommendations for Hospitalized Patients Under Investigation (PUIs) for Ebola Virus Disease (EVD) in U.S. Hospitals, designed to prevent the spread of disease from any possible index case [CDC-IC], but advice to people living in Africa tends to be sparse, basic and crude.
Confusion, rumours, misinformation and panic were a feature of the 2014 outbreak. [Indie]
Is there legal protection for
workers and others?
It is unlikely that specific rules exist; provided warnings of infection are posted, then travelers move at their own risk; those employed in affected areas, particularly health care professionals, may have recourse if their information. resources or protection are compromised.
What can be learned from
The New England Journal of Medicine explored this question in some detail, and this summarizes their conclusions [NEJM]:
The world needs to build a warning and response system for outbreaks. This system should
- be coordinated by a global institution that is given enough authority and funding to be effective,
- enable fast decision making at a global level,
- expand investment in research and development and clarify regulatory pathways for developing new tools and approaches,
- improve early warning and detection systems, including scalable everyday systems that can be expanded during an epidemic,
- involve a reserve corps of trained personnel and volunteers,
- strengthen health systems in low- and middle-income countries, and
- incorporate preparedness exercises to identify the ways in which the response system needs to improve.
Where can I get more information
About Ebola Virus Disease - CDC
Ebola: UK screening procedures to be reviewed - BBC
Ebola: The race for drugs and vaccines - BBC
Ebola virus and Marburg virus - Mayo Clinic
Ebola virus disease - WHO Factsheet - WHO
Ebola Virus Infection - WebMD
Infection Prevention and Control Recommendations for Hospitalized Patients Under Investigation (PUIs) for Ebola Virus Disease (EVD) in U.S. Hospitals - CDC-IC
Panic as deadly Ebola virus spreads across West Africa - Independent
The Next Epidemic — Lessons from Ebola - NEJM
What Are the Long-Term Effects of Ebola? - LiveScience
Wikipedia: List of Ebola Outbreaks
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Article written by Andrew Heenan BA (Hons), RGN, RMN