MANILA, Philippines ? Airport personnel in Manila were told to ?stay alert? to prevent the spread of the Influenza A(H1N1) virus, which has infected over 600 people in the country.

?No cause for alarm, but let?s stay alert and prepared,? Alfonso Cusi, general manager of the Manila International Airport Authority told airport workers and travelers.

Cusi also appealed for understanding of new restrictions imposed by the agency related to A(H1N1), saying the risk of catching the disease at the Ninoy Aquino International Airport, the country?s premiere international gateway, was ?high.?

?I appeal to airport workers to continue with their work responsibilities and passengers to go on with their planned activities unperturbed,? he said in a statement.

?As gateway keepers, all we must do is continue observing safety guidelines issued by the DoH [Department of Health], through the Bureau of Quarantine, to remain protected from acquiring the virus in the course of doing our jobs here at the NAIA,? he added.

Donations from private companies have boosted the airport?s supply of soap and hand sanitizers, said MIAA assistant general manager for airport development and corporate affairs Tirso Serrano.

At the onset of the flu scare, Cusi issued directives to limit the presence of non-airport personnel at the NAIA except in ?extremely necessary? circumstances.

The issuance of visitor passes to send off or meet passengers has been temporarily suspended. Filming activities within the complex have also been put off indefinitely.

Even requests for media coverage at the NAIA complex, especially within the terminal premises, are now being discouraged.

?We hope people will understand and see the wisdom in what we are doing. Airports are transit points for people coming from different parts of the world. The risk is high in this place,? Cusi said.