Spanish authorities say a 32-year-old woman from Alicante has symptoms of hantavirus infection and is being tested.
The woman was on the same flight as a Dutch woman who was on the MV Hondius cruise ship and later died from the virus.
Officials said the woman was showing “mild respiratory symptoms” and was kept in isolation at the hospital.
Health State Secretary Javier Padilla said test results were expected within 24 hours.
He said the woman was sitting two rows behind a Dutch passenger – the wife of the first person to die in the outbreak – who was briefly on the plane from Johannesburg to the Netherlands on April 25, but was removed before takeoff.
He later died in a hospital in Johannesburg.
flight attendant tests negative
A KLM flight attendant who came into contact with the same infected passenger and later showed mild symptoms has tested negative, WHO said on Friday.
KLM said Dutch health authorities were contacting people who were on the flight “as a precaution”.
Three passengers aboard the Hondias cruise ship died from what experts have identified as the Andes strain of hantavirus — a variant that can spread from human to human, but usually only after close contact.
Countries around the world are currently tracking passengers who were on the ship to prevent further spread of the virus.
Suspicion of third British infection
On Friday, another suspected case of the virus was identified in a British citizen on the South Atlantic island of Tristan da Cunha.
The British Health Protection Agency did not disclose further details.
Hondius stopped at a remote island on 15 April.
Two other British citizens on board have tested positive for the virus and are being treated in hospitals in the Netherlands and South Africa.
No evidence of hantavirus in German case
A woman transferred to a hospital in the German city of Düsseldorf is showing no symptoms of hantavirus infection.
The 65-year-old cruise ship passenger was picked up on the Atlantic island of Cape Verde on Wednesday after she was in close contact with another passenger who later died.
After being taken to the Netherlands he was transferred to Düsseldorf for trial.
The hospital said tests so far have failed to detect hantavirus, but protective measures will remain in place as it may take “several weeks” for symptoms to appear.
Singapore residents test negative
Meanwhile, two Singaporeans aboard the MV Hondius have tested negative for the virus.
The two men, aged 65 and 67, disembarked from the ship in St Helena and were on the same flight to Johannesburg on 25 April as a confirmed hantavirus case.
Singapore’s Communicable Disease Agency said they would be quarantined for 30 days as a precaution and would undergo further testing before being released.