Generally-speaking, diagnosis of the Ebola virus is only possible from the moment the first symptoms appear. The fact that it shares similar symptoms (such as fever) with other diseases means that diagnosis during the initial symptomatic stage requires other types of disease that initially present with similar symptomatology to be discarded. Once these have been discarded, a blood sample is taken and sent to the reference laboratory (in Spain, this is the Centro Nacional de Microbiología [National Microbiology Centre] which reports to the Instituto de Salud Carlos III [Carlos III Health Institute]), where a Polymerase Chain Reaction (PCR) test is performed. Whether the sample is positive or negative for the Ebola virus will be known within 24 hours.
In the following cases, a second analysis after 72 hours is necessary in order to discard false negatives or false positives:
- If circumstances involve (high-risk*) direct contact with an infected person
- If the situation involves someone arriving in Spain from an affected country within the last 72 hours
- If the symptoms are very weak
Someone with no symptoms will always produce a negative result from this analysis even if they are infected, meaning that a new analysis must be performed as soon as symptoms appear.
* High-risk contact means direct contact with a confirmed case without suitable personal protection equipment, or with their clothes, bedclothes or other material that may be infected with their blood, urine or bodily fluids, or direct contact with the body of a person who died from the Ebola virus disease.