Manila  - The Philippines has confirmed its first case of swine flu, prompting authorities on Friday to urge the public to remain calm but vigilant against the disease.

Health Secretary Francisco Duque said the first case is a 10-year- old girl who had travelled to Canada and the United States before returning on Monday.

The girl, who has been confined in a undisclosed hospital, was tested for the influenza A(H1N1) virus when she developed fever, cough and sore throat on Tuesday in Manila.

"The patient was started on anti-viral and given supportive care," Duque said. "The patient no longer has fever and cough, but she still has sore throat."

Relatives and others who had been in close contact with the girl have already been advised to go on quarantine.

Duque called for calm amid the confirmed case, stressing that authorities were on top of the situation.

"We advise the public not to panic," he said. "There is no community-level outbreak. Measures are being implemented to prevent transmission.

Health Undersecretary Mario Villaverde said that co-passengers of the girl in the plane were being contacted to advise them to observe self-quarantine.

He advised the public to observe personal hygiene, eat nutritional food, get enough sleep, drink lots of water and fruit juices and take vitamins to strengthen their immune systems.

"If you can postpone travelling to other affected areas, that would be good for you," he said.

The World Health Organization has recorded more than 11,000 cases of confirmed swine flu in 41 countries since April, with 85 deaths. The largest number of victims are in Mexico and the United States. (dpa)