The Philippines on Thursday asked more than 400 passengers who shared an airline flight with a man infected with the MERS virus to check in with the health department immediately.
The move was a precautionary measure to ensure none of them were infected by the man who has since been quarantined along with his family, a health official said.
Passengers on the Etihad Airways flight on April 15 were told to call health department emergency numbers listed in the media even while the department tries to track them down, said Lyndon Lee Suy, the spokesman for the department's emergency service.
"We want to make sure that none of them would have gotten the virus. We don't want to miss a single case," he told AFP.
The 418 passengers will be asked if they have fever or flu-like symptoms that might be signs of the sometimes fatal MERS.
The spokesman could not immediately say how many of the passengers had already been contacted.
A Filipino who arrived on the flight from the United Arab Emirates has tested positive for the MERS (Middle East Respiratory Syndrome) virus, the department announced on Wednesday.
The World Health Organisation said last Friday that it had been told of 212 laboratory-confirmed cases of MERS infection worldwide, of which 88 had proved fatal.
The MERS virus is considered a deadlier but less-transmissible cousin of the SARS virus that erupted in Asia in 2003 and infected 8,273 people, nine percent of whom died.