Ebola Hemorrhagic Fever
- Ebola [ee-BO-luh] hemorrhagic fever is a
deadly disease that has occurred in outbreaks
in Central Africa.
- Ebola hemorrhagic fever is caused by several
Ebola viruses. The source of these viruses
in nature is not known.
- People can get Ebola hemorrhagic fever by
direct contact with virus-infected blood,
body fluids, organs, or semen.
- There is no known cure or treatment.
- Recent outbreaks in humans have occurred
in areas where medical supplies and care were
inadequate. The outbreaks were controlled
by using barrier nursing techniques.
- Under normal circumstances, travelers are
at low risk of getting the disease. To eliminate
the risk, travelers should avoid areas where
Ebola outbreaks are occurring.
What is Ebola hemorrhagic fever?
Ebola hemorrhagic fever is one of the deadliest
of a group of diseases called viral hemorrhagic
fevers. They range in seriousness from relatively
mild illnesses to severe and potentially fatal
diseases. All forms of viral hemorrhagic fever
begin with fever and muscle aches. Depending
on the virus, the disease can get worse until
the patient becomes very ill with breathing
problems, severe bleeding (hemorrhage), kidney
problems, and shock.
Viral hemorrhagic fevers are caused by viruses
from four families: filoviruses, arenaviruses,
flaviviruses, and bunyaviruses. The usual hosts
for most of these viruses are rodents or arthropods
(such as ticks and mosquitoes). In some cases,
the natural host for the virus is not known.
What is the infectious agent that causes
Ebola hemorrhagic fever?
Ebola hemorrhagic fever is caused by several
Ebola viruses. Ebola viruses are members of
the filovirus family; when magnified several
thousand times by an electron microscope, these
viruses look like threads (filaments). Ebola
virus was discovered in 1976 and named for a
river in Zaire, Africa, where it was first detected.
Where is Ebola hemorrhagic fever found?
Ebola viruses are found in Central Africa.
The source of the viruses in nature remains
unknown. Monkeys, like humans, appear to be
susceptible to infection and might serve as
a source of virus if infected.
How do people get Ebola hemorrhagic fever?
People get the disease by direct contact with
virus-infected blood, body fluids, organs, or
semen.
The disease is spread mainly by close person-to-person
contact with severely ill patients. This happens
most often to hospital-care workers and family
members who care for an ill person infected
with Ebola virus. Close personal contact with
persons who are infected but show no signs of
active disease is very unlikely to result in
infection.
Transmission of the virus has also been linked
to the re-use of hypodermic needles in the treatment
of patients. Re-using needles is a common practice
in developing countries, such as Zaire and Sudan,
where the health-care system is underfinanced.
Medical facilities in the United States do not
re-use needles.
Ebola virus can be spread from person to person
through sexual contact. Persons who have recuperated
from an illness caused by Ebola virus can still
have the virus in their genital secretions for
a short time after recovery and can spread the
virus through sexual activity.
What are the signs and symptoms of Ebola
hemorrhagic fever?
People infected with Ebola virus have sudden
fever, weakness, muscle pain, headache, and
sore throat, followed by vomiting, diarrhea,
rash, limited kidney and liver functions, and
both internal and external bleeding. Death rates
range from 50% to 90%.
How soon after exposure do symptoms appear?
Symptoms begin 2 to 21 days after infection.
How is Ebola hemorrhagic fever diagnosed?
Diagnosis requires specialized laboratory tests
on blood specimens. Handling blood from a persons
infected with Ebola virus is an extreme biohazard
and can be done only in specially equipped laboratories.
Diagnosis in patients who have died can be made
by testing tissue samples.
Who is at risk for Ebola hemorrhagic fever?
- Persons traveling to areas where Ebola hemorrhagic
fever is occurring
- Hospital staff and family members who care
for patients with Ebola hemorrhagic fever
- Central African residents of rural areas
and small towns
What is the treatment for Ebola hemorrhagic
fever?
There is no known cure or treatment. Severe
cases need intensive supportive care.
How common is Ebola hemorrhagic fever?
Until recently, only three outbreaks of Ebola
hemorrhagic fever in humans had been reported.
The first two, in 1976 in Zaire and in western
Sudan, were large outbreaks that resulted in
more than 550 cases and 340 deaths. The third
outbreak, in 1979 in Sudan, was smaller, with
34 cases and 22 deaths. In each of these outbreaks,
most cases occurred in hospitals where medical
supplies were inadequate and where needles and
syringes were re-used. The outbreaks were quickly
controlled by isolating sick patients in a place
requiring the wearing of mask, gown, and gloves;
sterilizing needles and syringes; and disposing
of wastes and corpses in a sanitary way.
In 1995, an outbreak in Kikwit and surrounding
areas in Bandundu Province, Zaire, caused 316
deaths. The outbreak was amplified in a hospital
by staff who became infected through poor nursing
techniques. At the request of health officials
in Zaire, medical teams from CDC and the World
Health Organization, and from Belgium, France,
and South Africa, collaborated to investigate
and control the outbreak.
Two isolated cases of Ebola hemorrhagic fever
were identified in Cote d'Ivoire in 1994-1995.
The most recent outbreaks were in rural Gabon
in 1994 and in 1996. A patient from the 1996
Gabon outbreak traveled to Johannesburg, South
Africa, and fatally infected a health-worker
there as well.
How can Ebola hemorrhagic fever be prevented?
Under normal circumstances, travelers are at
low risk of getting the disease. To eliminate
the risk, travelers should avoid areas where
Ebola outbreaks are occurring.
This fact sheet is for information only and
is not meant to be used for self-diagnosis or
as a substitute for consultation with a health-care
provider. If you have any questions about the
disease described above, consult a health-care
provider.
