Dusseldorf  - Officials were waiting Friday for more lab test results from a Japanese school in the German city of Dusseldorf where at least 46 pupils have come down with swine flu, possibly after a child caught the virus at an airport.

One day after the World Health Organization (WHO) declared a pandemic, the new strain of H1N1 virus was continuing its spread in Germany, which is western Europe's most populous nation.

At the Japanese school more than 300 people, including parents, were swabbed on Thursday and the samples were sent to a laboratory to establish how many had been infected with the virus.

Emerging from the tests with his wife and 8-year-old son, one man, 40, told the German Press Agency dpa that his daughter, 11, had caught the strain of H1N1 at the school and the whole family would now be spending a week in self-enforced quarantine.

"We'll stay home and wait till we hear our test results," he said. "We don't have much food stocked up."

The Japanese consulate-general in the city said it was delivering key medicines direct to the homes of the Japanese expatriate community, which numbers 7,600 people in Dusseldorf, where many Japanese multinationals have their European bases.

Another man said corporate employers, fearing the virus would spread, were more relaxed than usual about staff calling in sick.

The results of most of the tests were expected in the course of Friday.

Heiko Schneitler, head of the Dusseldorf Health Office, said earlier most of the cases were not severe, but one child had required hospital treatment. Some 50 teachers and 530 students are registered at the school.

The first case involved a 6-year-old who had just returned from a holiday with his family on the Maltese island of Gozo in the Mediterranean Sea, Schneitler said. The health official said it was possible the child picked up the infection at an airport.

An outbreak which affected two children in a Munich kindergarten spread to a third child, a 5-year-old boy. The German armed forces were monitoring 60 personnel who had been on a training mission in the United States after one of them, an officer, 36, came down with H1N1.(dpa)