Swine flu has led Tokyo’s Narita Airport to increase its number of on-site health professionals to 280.

The airport said that 46,000 travellers are returning from the US following Japan’s Golden Week holiday, heightening the risk swine flu entering the country.

The airport authority has more than tripled the number of doctors and nurses available at Narita, Kansai International and Central Japan International airports to check swine flu infection in passengers, the Kyodo news agency reports.

Though Japan is yet to witness any swine flu cases there have been several cases of passengers testing positive for the influenza A virus, which turned out to be different strains of flu.