Ebola virus disease (EVD), formerly known as Ebola
haemorrhagic fever, is a severe, often fatal illness in
humans. Ebola is introduced into the human
population through close contact with the blood,
secretions, organs or other bodily fluids of infected
In Africa, infection has been documented through the
handling of infected chimpanzees, gorillas, fruit bats,
monkeys, forest antelope and porcupines found ill or
dead or in the rainforest.
Ebola then spreads in the community through human-
to-human transmission, with infection resulting from direct contact (through broken skin or mucous
membranes) with the blood, secretions, organs or
other bodily fluids of infected people, and indirect
contact with environments contaminated with such
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.
Men who have
recovered from the disease can still transmit the virus
through their semen for up to 7 weeks after recovery
Signs and symptoms
Ebola virus disease (EVD) is a severe acute viral illness
often characterized by the sudden onset of fever,
intense weakness, muscle pain, headache and sore
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.
People are infectious as long as their blood and
secretions contain the virus.
Ebola virus was isolated
from semen 61 days after onset of illness in a man
who was infected in a laboratory.
The incubation period, that is, the time interval from
infection with the virus to onset of symptoms, is 2 to 21 days.
Supportive care-rehydration with oral or
intravenous fluids- and treatment of specific
symptoms, improves survival. There is as yet no
proven treatment available for EVD. However, a
range of potential treatments including blood
products, immune therapies and drug therapies are currently being evaluated.
An experimental Ebola vaccine proved highly
protective against the deadly virus in a major trial
in Guinea. The vaccine, called rVSV-ZEBOV, was
studied in a trial involving 11 841 people during
Among the 5837 people who received the
vaccine, no Ebola cases were recorded 10 days or more after vaccination.
In comparison, there were
23 cases 10 days or more after vaccination among
those who did not receive the vaccine.
The trial was led by WHO, together with Guinea's
Ministry of Health, Médecins sans Frontieres and the
Norwegian Institute of Public Health, in
collaboration with other international partners. A
ring vaccination protocol was chosen for the trial,
where some of the rings are vaccinated shortly after a case is detected, and other rings are
vaccinated after a delay of 3 weeks.
Educational public health messages is necessary for
preventing and reducing risk of contacting Ebola virus.
Awareness should focus on several factors:
*. Reducing the risk of wildlife-to-human transmission
from contact with infected fruit bats or monkeys/apes
and the consumption of their raw meat.
Animals should be handled with gloves and other appropriate
Animal products (blood and meat)
should be thoroughly cooked before consumption.
*. Reducing the risk of human-to-human transmission in
the community arising from direct or close contact
with infected patients, particularly with their bodily
Close physical contact with Ebola patients
should be avoided.
Gloves and appropriate personal
protective equipment should be worn when taking care of ill patients at home.
Regular hand washing is
required after visiting patients.
Pig farms in Africa can play a role in the amplification
of infection because of the presence of fruit bats on
Gloves and other appropriate protective
clothing should be worn when handling sick animals
or their tissues and when slaughtering animals.
regions where Ebola virus has been reported in pigs, all animal products (blood, meat and milk) should be
thoroughly cooked before eating.
Human-to-human transmission of the Ebola virus is
primarily associated with direct or indirect contact
with blood and body fluids.
Transmission to health-care workers has been reported when appropriate
infection control measures have not been observed.
It is not always possible to identify patients with Ebola
virus disease (EVD) early because initial symptoms
may be non-specific.
For this reason, it is important
that health-care workers apply standard precautions
consistently with all patients – regardless of their
diagnosis – in all work practices at all times. These include basic hand hygiene, respiratory hygiene, the
use of personal protective equipment (according to
the risk of splashes or other contact with infected
materials), safe injection practices and safe burial
Health-care workers caring for patients with
suspected or confirmed Ebola virus should apply, in
addition to standard precautions, other infection
control measures to avoid any exposure to the
patient's blood and body fluids and direct
unprotected contact with the possibly contaminated environment.
When in close contact (within 1 metre)
of patients with EBV, health-care workers should
wear face protection (a face shield or a medical mask
and goggles), a clean, non-sterile long-sleeved gown,
and gloves (sterile gloves for some procedures).
Laboratory workers are also at risk. Samples taken
from suspected human and animal Ebola cases for
diagnosis should be handled by trained staff and
processed in suitably equipped laboratories.
SOURCE: World Health Organization