The swine flu pandemic is expected to hit Switzerland with full force in the next few days, according to the health authorities.
Confirmed cases of swine flu tripled last week to about 2,000 and were set to increase noticeably in the immediate future, Patrick Mathys of the Federal Health Office said on Thursday.
"We cannot stop the wave from reaching the country now that the pandemic has spread in the northern hemisphere," he said.
In total tens of thousands of people with flu symptoms had consulted a doctor and were believed to have come down with a mild form of the illness. So far 38 people have been admitted to hospital, including six who are still in intensive care.
Geneva and the southern Ticino region have recorded the biggest increase in flu cases, but there are also cases in Zurich schools and in army barracks elsewhere in the country.
Mathys said he hoped a vaccination campaign, to begin in mid-November, would help protect risk groups, including pregnant women, the chronically ill as well as health workers.
He said it was impossible to foresee the peak of the flu wave, which normally lasts up to 12 weeks.
Health officials said there was no need to review preventive measures and reiterated the importance of good hygiene to stem the spread of the N1/H1 influenza virus.
The authorities have planned a two-phase immunisation campaign, but have stopped short of mandatory vaccinations.
Urs Geiser, swissinfo.ch