MEXICO CITY - The next wave of swine flu has arrived, and Mexicans are bracing for an outbreak that may be even larger than the one here last spring that became a pandemic.

Daily diagnoses reached higher levels in September than the H1N1 peak in April, with 483 new cases in just one day this month alone.

It's unlikely there will be large-scale closings of schools and stadiums, however, because health officials know the virus is usually mild if treated early.

"We know the situation is not as serious" as officials feared last spring, said Health Secretary Jose Angel Cordova.

Still, 3,000 schools across Mexico were closed earlier this week as a result of the virus. That number has dropped to 128, Education Secretary Alonso Lujambio told senators Wednesday, as he said officials are still developing the criteria they will use to shut down schools in the future.

When the first cases of swine flu were confirmed in late April, Mexico's government immediately ordered the closure of all schools, museums, libraries and theaters in the capital. Within days, schools nationwide, restaurant dining rooms and other businesses shut down, streets mostly emptied and soldiers handed out millions of face masks.

Mexico could see up to 5 million cases of swine flu during this winter's flu season and deaths could reach 2,000, Cordova said.

Some hospitals already have the same number of swine flu patients as they had in April, he said Thursday. Officials are negotiating with laboratories to secure doses of a vaccine by October, he added.

Mexico had 29,417 reported cases and 226 deaths as of Friday.

The World Health Organization says more than 300,000 cases of H1N1 have been confirmed throughout the world, and more than 3,900 people have died from the virus.