German health authorities examined two women for possible bird flu infection on Monday but said initial tests suggested they were not infected with the disease now sweeping Asia.

One of the women had returned from a trip to Thailand on Saturday and been taken to hospital complaining of sickness, dizziness and fever. Her female companion, who had no symptoms, has also undergone tests.

"There is nothing to suggest it is bird flu," Professor Bernhard Fleischer, director of the Bernhard Nocht Institute for Tropical Medicine in the northern city of Hamburg, told reporters after receiving the first results of clinical tests. "At this point it seems bird flu is unlikely."

The results of further tests will be available on Monday evening or Tuesday.

Shares in Deutsche Lufthansa and tour operator TUI had fallen on the news of the possible bird flu cases, which could affect bookings from German tourists.

Had they been confirmed, the infections would have been the first in Europe in the latest epidemic, which has so far killed 12 people and affected 10 countries in Asia.

Officials from Hamburg's health authority and from the Robert Koch Institute in Berlin, Germany's top health institute, said the women were very unlikely to be infected with bird flu.

Gerd-Dieter Burchard, the doctor treating the woman at the Hamburg institute, said she was a young German woman who had had no contact with poultry in Thailand. He gave no further details. "It's a very low level of suspicion but we cannot rule it out and can take no risks," said Burchard.

Scientists fear the epidemic in Asia may now be transmitted from person to person. The EU's health chief said he was closely monitoring the possible spread of bird flu from human to human in Asia but no immediate additional steps were planned within the trading bloc.

"The World Health Organization hasn't confirmed the human-to-human transmission in Vietnam, but it's very worrying," EU Health and Consumer Protection Commissioner David Byrne said.

The 15-nation bloc has banned imports of fresh and frozen poultry from Thailand and also halted trade in exotic birds from the 10 states affected with bird flu to stop the spread of the highly contagious disease.

(Reuters)