Ebola virus disease (formerly known as Ebola
haemorrhagic fever) is a severe, often fatal illness,
with a case fatality rate of up to 90%. It is one of the
world’s most virulent diseases.The infection is
transmitted by direct contact with the blood, body
fluids and tissues of infected animals or people.
Severely ill patients require intensive supportive
care.
During an outbreak, those at higher risk of
infection are health workers, family members and
others in close contact with sick people and
deceased patients.
Ebola virus disease outbreaks can devastate
families and communities, but the infection can be
controlled through the use of recommended
protective measures in clinics and hospitals, at
community gatherings, or at home.
Infection and transmission
In Africa, fruit bats are believed to be the natural
hosts of Ebola virus. The virus is transmitted from
wildlife to people through contact with infected
fruit bats, or through intermediate hosts, such as
monkeys, apes, or pigs that have themselves
become infected through contact with bat saliva or
faeces.
People may then become infected through contact
with infected animals, either in the process of
slaughtering or through consumption of blood,
milk, or raw or undercooked meat.
The virus is then passed from person to person
through direct contact with the blood, secretions or
other bodily fluids of infected persons, or from
contact with contaminated needles or other
equipment in the environment.
Signs and symptoms
EVD, which has a case fatality rate of up to 90%, is a
severe acute viral illness often characterized by the
sudden onset of fever, intense weakness, muscle
pain, headache, nausea and sore throat. This is
followed by vomiting, diarrhoea, impaired kidney
and liver function, and in some cases, both internal
and external bleeding. Laboratory findings
frequently include low white blood cell and platelet
counts and elevated liver enzymes.
The incubation period, the time interval from
infection with the virus to onset of symptoms, is 2
to 21 days. People remain infectious as long as
their blood and secretions contain the virus, a
period that has been reported to be as long as 61
days after onset of illness.
Diagnosis and treatment
When considering the diagnosis of EVD, other,
more common diseases should not be overlooked;
for example, malaria, typhoid fever, shigellosis,
cholera, leptospirosis, plague, rickettsiosis,
relapsing fever, meningitis, hepatitis and other viral
haemorrhagic fevers.
Definitive diagnosis of EVD is made through
laboratory testing. Because samples from patients
are a source of infection risk for others, testing is
conducted under maximum biological containment
conditions.
No vaccine is available, nor is there any specific
treatment. Severely ill patients require intensive
supportive care. Patients are frequently dehydrated
and require oral rehydration with solutions
containing electrolytes, or intravenous fluids.
Preventative measures
Raising awareness of the risk factors for infection
and the protective measures that should be taken is
the only way to reduce human infection and
subsequent deaths. Close unprotected physical
contact with Ebola patients should be avoided.
Appropriate use of gloves and personal protective
equipment (including hand hygiene before putting
on, and especially after taking off personal
protective equipment) should be practised when
taking care of ill patients at home. Regular hand
washing is required after visiting patients in
hospital, as well as after taking care of patients at
home.
Almost all transmission of the virus to health-care
workers has been reported when basic infection
control measures have not been observed. Health-
care workers caring for any patient should practice
standard precautions. When caring for patients
with suspected or confirmed Ebola virus infection,
health-care workers should apply, in addition to
standard precautions, other infection control
measures to avoid any exposure to patients’ blood
and body fluids and with possibly contaminated
environments.
Preparation for burial of the bodies of persons who
have died from Ebola virus disease also carries
high risks of transmission of the virus. Those who
have died from the disease should be promptly and
safely buried.
haemorrhagic fever) is a severe, often fatal illness,
with a case fatality rate of up to 90%. It is one of the
world’s most virulent diseases.The infection is
transmitted by direct contact with the blood, body
fluids and tissues of infected animals or people.
Severely ill patients require intensive supportive
care.
During an outbreak, those at higher risk of
infection are health workers, family members and
others in close contact with sick people and
deceased patients.
Ebola virus disease outbreaks can devastate
families and communities, but the infection can be
controlled through the use of recommended
protective measures in clinics and hospitals, at
community gatherings, or at home.
Infection and transmission
In Africa, fruit bats are believed to be the natural
hosts of Ebola virus. The virus is transmitted from
wildlife to people through contact with infected
fruit bats, or through intermediate hosts, such as
monkeys, apes, or pigs that have themselves
become infected through contact with bat saliva or
faeces.
People may then become infected through contact
with infected animals, either in the process of
slaughtering or through consumption of blood,
milk, or raw or undercooked meat.
The virus is then passed from person to person
through direct contact with the blood, secretions or
other bodily fluids of infected persons, or from
contact with contaminated needles or other
equipment in the environment.
Signs and symptoms
EVD, which has a case fatality rate of up to 90%, is a
severe acute viral illness often characterized by the
sudden onset of fever, intense weakness, muscle
pain, headache, nausea and sore throat. This is
followed by vomiting, diarrhoea, impaired kidney
and liver function, and in some cases, both internal
and external bleeding. Laboratory findings
frequently include low white blood cell and platelet
counts and elevated liver enzymes.
The incubation period, the time interval from
infection with the virus to onset of symptoms, is 2
to 21 days. People remain infectious as long as
their blood and secretions contain the virus, a
period that has been reported to be as long as 61
days after onset of illness.
Diagnosis and treatment
When considering the diagnosis of EVD, other,
more common diseases should not be overlooked;
for example, malaria, typhoid fever, shigellosis,
cholera, leptospirosis, plague, rickettsiosis,
relapsing fever, meningitis, hepatitis and other viral
haemorrhagic fevers.
Definitive diagnosis of EVD is made through
laboratory testing. Because samples from patients
are a source of infection risk for others, testing is
conducted under maximum biological containment
conditions.
No vaccine is available, nor is there any specific
treatment. Severely ill patients require intensive
supportive care. Patients are frequently dehydrated
and require oral rehydration with solutions
containing electrolytes, or intravenous fluids.
Preventative measures
Raising awareness of the risk factors for infection
and the protective measures that should be taken is
the only way to reduce human infection and
subsequent deaths. Close unprotected physical
contact with Ebola patients should be avoided.
Appropriate use of gloves and personal protective
equipment (including hand hygiene before putting
on, and especially after taking off personal
protective equipment) should be practised when
taking care of ill patients at home. Regular hand
washing is required after visiting patients in
hospital, as well as after taking care of patients at
home.
Almost all transmission of the virus to health-care
workers has been reported when basic infection
control measures have not been observed. Health-
care workers caring for any patient should practice
standard precautions. When caring for patients
with suspected or confirmed Ebola virus infection,
health-care workers should apply, in addition to
standard precautions, other infection control
measures to avoid any exposure to patients’ blood
and body fluids and with possibly contaminated
environments.
Preparation for burial of the bodies of persons who
have died from Ebola virus disease also carries
high risks of transmission of the virus. Those who
have died from the disease should be promptly and
safely buried.
