Joan Tishkevich’s joy was unequivocal. “YES!” the mother of two shouted into the phone Tuesday after hearing that federal health officials were no longer advising schools to close for swine flu.

It meant her 8-year-old son, Jack, would soon go back to his second-grade classroom. It meant he could return to his beloved Little League.

Most of all, it meant Tishkevich would be able to stop bringing the boy to her office, leaving him to read books while she held meetings at the real estate development company where she works in Kennebunk, Maine.

Last week, the government advised schools to shut down for about two weeks if there were suspected cases of swine flu. Some 700 schools around the country followed that guidance, affecting about 468,000 kids.

Hundreds of thousands of parents scrambled to meet an unexpected logistical challenge: What to do with the kids?

But on Tuesday, Health and Human Services Secretary Kathleen Sebelius said the swine flu virus had turned out to be milder than initially feared, and thus the change in advice: No need to close schools, but do keep sick children with flulike symptoms at home for at least seven days.

Also Tuesday, Texas health officials confirmed the first death of a U.S. resident with swine flu. Authorities said the 33-year-old schoolteacher’s death was a combination of the flu and chronic health problems, and not a reason to panic.

Mercedes Independent School District, where the woman taught, announced it would close its schools starting today and reopen Monday.

Nationwide, it seemed school districts were acting immediately to the federal advice. Some queried by The Associated Press said they would reopen today. Most others said they would wait until Thursday. A few planned to wait until Monday.

In changing their advice, health officials said they had considered the problems the closings created for parents.

Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention, said officials heard about children getting dropped off at libraries or about parents who could not take sick leave to care for children. “The downsides of school closure start to outweigh the benefits,” Besser said.

That certainly rang true for parents like Lien Addo, an engineer in Silicon Valley. Her daughter’s preschool in West San Jose, Calif., had closed Friday after a student in a higher grade came down with a probable case of swine flu.

After a series of phone calls, Addo had arranged for various friends to watch her daughter. Reached on her cell phone Tuesday, she was relieved to hear she would soon be able to stop the makeshift scheduling. “That’s great,” said Addo, 35. “My daughter loves school.”

But like many parents, Addo had supported the closure at first, despite the hassles, based on what officials knew at the time.

“I’d rather have them be on the precautionary side than to have a widespread flu epidemic at the school,” she said.

To other parents, the new government advice was merely confirmation of their belief that officials had overreacted.

“It seems like they all jumped the gun,” said Laurie Williams, mother of a sixth-grader and a kindergartner in Flower Mound, Texas, near Dallas. “It was an overreaction. It’s just a flu.”