1. What is Ebola virus disease?
Ebola virus disease (formerly known as Ebola haemorrhagic
fever) is a severe, often fatal illness, with a death rate of up to 90%. The
illness affects humans and nonhuman primates (monkeys, gorillas, and
chimpanzees).
Ebola first appeared in 1976 in two simultaneous outbreaks,
one in a village near the Ebola River in the Democratic Republic of Congo, and
the other in a remote area of Sudan.
The origin of the virus is unknown but fruit bats
(Pteropodidae) are considered the likely host of the Ebola virus, based on
available evidence.
2. How do people become infected with the virus?
Ebola is introduced into the human population through close
contact with the blood, secretions, organs or other bodily fluids of infected
animals. In Africa, infection has occurred through the handling of infected
chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines
found ill or dead or in the rainforest. It is important to reduce contact with
high-risk animals (i.e. fruit bats, monkeys or apes) including not picking up
dead animals found lying in the forest or handling their raw meat.
Once a person comes into contact with an animal that has
Ebola, it can spread within the community from human to human. Infection occurs
from direct contact (through broken skin or mucous membranes) with the blood,
or other bodily fluids or secretions (stool, urine, saliva, semen) of infected
people. Infection can also occur if broken skin or mucous membranes of a
healthy person come into contact with environments that have become
contaminated with an Ebola patient’s infectious fluids such as soiled clothing,
bed linen, or used needles.
Health workers have frequently been exposed to the virus
when caring for Ebola patients. This happens because they are not wearing
personal protection equipment, such as gloves, when caring for the patients.
Health care providers at all levels of the health system – hospitals, clinics
and health posts – should be briefed on the nature of the disease and how it is
transmitted, and strictly follow recommended infection control precautions.
Burial ceremonies in which mourners have direct contact with
the body of the deceased person can also play a role in the transmission of
Ebola. Persons who have died of Ebola must be handled using strong protective
clothing and gloves, and be buried immediately.
People are infectious as long as their blood and secretions
contain the virus. For this reason, infected patients receive close monitoring
from medical professionals and receive laboratory tests to ensure the virus is
no longer circulating in their systems before they return home. When the
medical professionals determine it is okay for the patient to return home, they
are no longer infectious and cannot infect anyone else in their communities.
Men who have recovered from the illness can still spread the virus to their
partner through their semen for up to 7 weeks after recovery. For this reason,
it is important for men to avoid sexual intercourse for at least 7 weeks after
recovery or to wear condoms if having sexual intercourse during 7 weeks after
recovery.
3. Who is most at risk?
During an outbreak, those at higher risk of infection are:
health workers;
family members or
others in close contact with infected people;
mourners who have
direct contact with the bodies of the deceased as part of burial ceremonies;
and
hunters in the
rain forest who come into contact with dead animals found lying in the forest.
More research is needed to understand if some groups, such
as immuno-compromised people or those with other underlying health conditions,
are more susceptible than others to contracting the virus.
Exposure to the virus can be controlled through the use of
protective measures in clinics and hospitals, at community gatherings, or at
home.
4. What are typical signs and symptoms of infection?
Sudden onset of fever, intense weakness, muscle pain, headache
and sore throat are typical signs and symptoms. This is followed by vomiting,
diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal
and external bleeding.
Laboratory findings include low white blood cell and
platelet counts, and elevated liver enzymes.
The incubation period, or the time interval from infection
to onset of symptoms, is from 2 to 21 days. The patients become contagious once
they begin to show symptoms. They are not contagious during the incubation
period.
Ebola virus disease infections can only be confirmed through
laboratory testing.
5. When should someone seek medical care?
If a person has been in an area known to have Ebola virus
disease or in contact with a person known or suspected to have Ebola and they
begin to have symptoms, they should seek medical care immediately.
Any cases of persons who are suspected to have the disease
should be reported to the nearest health unit without delay. Prompt medical
care is essential to improving the rate of survival from the disease. It is
also important to control spread of the disease and infection control
procedures need to be started immediately.
6. What is the treatment?
Severely ill patients require intensive supportive care.
They are frequently dehydrated and need intravenous fluids or oral rehydration
with solutions that contain electrolytes. There is currently no specific
treatment to cure the disease.
Some patients will recover with the appropriate medical
care.
To help control further spread of the virus, people that are
suspected or confirmed to have the disease should be isolated from other
patients and treated by health workers using strict infection control
precautions.
7. What can I do? Can Ebola be prevented?
Currently there is no licensed vaccine for Ebola virus
disease. Several vaccines are being tested, but none are available for clinical
use right now.
Raising awareness of the risk factors and measures people
can take to protect themselves are the only ways to reduce illness and deaths.
Ways to prevent infection and transmission
While initial cases of Ebola virus disease are contracted by
handling infected animals or carcasses, secondary cases occur by direct contact
with the bodily fluids of an ill person, either through unsafe case management
or unsafe burial practices. During this outbreak, most of the disease has
spread through human-to-human transmission. Several steps can be taken to help
in preventing infection and limiting or stopping transmission.
Understand the nature of the disease, how it
is transmitted, and how to prevent it from spreading further. (For additional
information, please see the previous questions about Ebola virus disease in
this FAQ.)
Listen to and
follow directives issued by your country’s respective Ministry of Health.
If you suspect
someone close to you or in your community of having Ebola virus disease,
encourage and support them in seeking appropriate medical treatment in a care
facility.
If you choose to
care for an ill person in your home, notify public health officials of your
intentions so they can train you and provide appropriate gloves and personal
protective equipment (PPE), as well as instructions as a reminder on how to
properly care for the patient, protect yourself and your family, and properly
dispose of the PPE after use.
When visiting
patients in the hospital or caring for someone at home, hand washing with soap
and water is recommended after touching a patient, being in contact with their
bodily fluids, or touching his/her surroundings.
People who have
died from Ebola should only be handled using appropriate protective equipment
and should be buried immediately.
Additionally, individuals should reduce contact with
high-risk infected animals (i.e. fruit bats, monkeys or apes) in the affected
rainforest areas. If you suspect an animal is infected, do not handle it.
Animal products (blood and meat) should be thoroughly cooked before eating.
8. What about health workers? How do they protect themselves from the high risk of caring for sick patients?
Health workers treating patients with suspected or confirmed
illness are at higher risk of infection than other groups.
In addition to
standard health care precautions, health workers should strictly apply
recommended infection control measures to avoid exposure to infected blood,
fluids, or contaminated environments or objects – such as a patient’s soiled
linen or used needles.
They should use
personal protection equipment such as individual gowns, gloves, masks and
goggles or face shields.
They should not
reuse protective equipment or clothing unless they have been properly
disinfected.
They should change
gloves between caring for each patient suspected of having Ebola.
Invasive
procedures that can expose medical doctors, nurses and others to infection should
be carried out under strict, safe conditions.
Infected patients
should be kept separate from other patients and healthy people, as much as
possible.
9. What about rumours that some foods can prevent or treat
the infection?
WHO strongly recommends that people seek credible health
advice about Ebola virus disease from their public health authority.
While there is no specific drug against Ebola, the best
treatment is intensive supportive treatment provided in the hospital by health
workers using strict infection control procedures. The infection can be
controlled through recommended protective measures.
10. How does WHO protect health during outbreaks?
WHO provides technical advice to countries and communities
to prepare for and respond to Ebola outbreaks.
WHO actions include: disease
surveillance and information-sharing across regions to watch for outbreaks; technical
assistance to investigate and contain health threats when they occur – such as
on-site help to identify sick people and track disease patterns; advice on
prevention and treatment options; deployments of
experts and the distribution of health supplies (such as personal protection
gear for health workers) when they are requested by the country; communications to
raise awareness of the nature of the disease and protective health measures to
control transmission of the virus; and activation of
regional and global networks of experts to provide assistance, if requested,
and mitigate potential international health effects and disruptions of travel
and trade.
11. During an outbreak, numbers of cases reported by health
officials can go up and down? Why?
During an Ebola outbreak, the affected country’s public
health authority reports its disease case numbers and deaths. Figures can
change daily. Case numbers reflect both suspected cases and
laboratory-confirmed cases of Ebola. Sometimes numbers of suspected and
confirmed cases are reported together. Sometimes they are reported separately.
Thus, numbers can shift between suspected and confirmed cases.
Analyzing case data trends, over time, and with additional
information, is generally more helpful to assess the public health situation
and determine the appropriate response.
12. Is it safe to travel during an outbreak? What is WHO’s
travel advice?
During an outbreak, WHO reviews the public health situation
regularly, and recommends any travel or trade restrictions if necessary.
The risk of infection for travelers is very low since
person-to-person transmission results from direct contact with the body fluids
or secretions of an infected patient.
WHO’s general travel advice:
Travelers should
avoid all contact with infected patients.
Health workers
traveling to affected areas should strictly follow WHO-recommended infection
control guidance.
Anyone who has
stayed in areas where cases were recently reported should be aware of the
symptoms of infection and seek medical attention at the first sign of illness.
Clinicians caring
for travelers returning from affected areas with compatible symptoms are
advised to consider the possibility of Ebola virus disease.
Source: World Health Organisation (WHO)
Source: World Health Organisation (WHO)
