The World Health Organization made it official Thursday, declaring that swine flu is now a global pandemic.
At the same time, Minnesota authorities reported that the number of confirmed cases in the state has more than doubled in a week, raising concerns that people have let down their guard too soon.
This week, an average of 30 new cases a day have been reported in Minnesota, according to the Minnesota Department of Health.
"I am concerned that people are not taking this seriously," said Dr. Ruth Lynfield, the Minnesota state epidemiologist. "This story," she added, "hasn't played out yet."
Ironically, Lynfield and other experts worry that Thursday's announcement -- of the first worldwide flu pandemic in 41 years -- could lull the public into complacency. This is the fourth pandemic in the last century, and so far, the least deadly.
"People are going to say, 'Geez, pandemics don't amount to much'," said Dr. Allan Kind, a retired Park Nicollet infectious disease specialist who now serves on a pandemic advisory panel for the state. "That," he said, "is going to be the problem."
As of Thursday, a total of 221 cases have been confirmed in Minnesota, according to Lynfield, and that represents only a fraction of the total, because the state relies on a sample survey from hospitals and 26 "sentinel" clinics.
"I am concerned that it may be that there's a bit more transmission because people aren't staying home when they're sick," Lynfield said.