Although federal health officials decline to use the word "peaked," the current wave of swine flu appears to have done so in the United States. Flu activity is coming down in all regions of the country, the Centers for Disease Control and Prevention said Friday, though it is still rising in Hawaii, Maine and some isolated areas. The World Health Organization said Friday that there were "early signs of a peak" in much of the United States. On Wednesday, the American College Health Association, which surveys over 250 colleges with more than three million students, said new cases of flu had dropped in the week ending Nov. 13. It was the first drop since school resumed in the fall, and it was significant new cases were down 27 percent from the week before. And on Friday, Quest Diagnostics, the country's largest laboratory, said its tests of 142,000 suspected flu specimens since May showed that the flu peaked in late October. Nonetheless, Dr. Anne Schuchat, the director of immunization and respiratory diseases at the C.D.C., chose her words carefully, saying: "I wish I knew if we had hit the peak. Even if a peak has occurred, half the people who are going to get sick haven't gotten sick yet." The drop was clearly not caused by the swine flu vaccine drive, which has not gone as fast as the authorities had hoped.