Symptoms of Ebola virus disease
The incubation period, that is,
the time interval from infection with the virus to onset of symptoms is 2 to 21
days. Humans are not infectious until they develop symptoms. First symptoms are
the sudden onset of fever fatigue, muscle pain, headache and sore throat. This
is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver
function, and in some cases, both internal and external bleeding (e.g. oozing
from the gums, blood in the stools). Laboratory findings include low white
blood cell and platelet counts and elevated liver enzymes.
It can be difficult to
distinguish EVD from other infectious diseases such as malaria, typhoid fever
and meningitis. Confirmation that symptoms are caused by Ebola virus infection
are made using the following investigations:
antibody-capture enzyme-linked immunosorbent assay (ELISA)
antigen-capture detection tests
serum neutralization test
reverse transcriptase polymerase chain reaction (RT-PCR) assay
virus isolation by cell culture.
Samples from patients are an
extreme biohazard risk; laboratory testing on non-inactivated samples should be
conducted under maximum biological containment conditions.