Associated Press: As if marshaling for war, Mexico's government mobilized thousands of education officials and parents across the country to swiftly disinfect schools and monitor millions of returning students for signs of swine flu.

High schools and universities open Thursday after a two-week closure intended to curb the spread of the virus. Younger children were ordered back to class on Monday.

Secretary of Public Education Alonso Lujambio called on Mexicans to show "strength of spirit," trying to assuage worries that it's too early to reopen schools after the flu outbreak that killed 42 people in Mexico and sickened more than 1,100.

Parents expressed relief that their children, shuttered too long in homes, could return to class. But they also worried that the virus could surge back once 40 million young people gather in groups again.

"My 17-year-old daughter is afraid. She knows she must go back but doesn't want to," said Silvia Mendez as she led her 4-year-old son, Enrique, down a narrow street in San Miguel Topilejo, a town perched in forested mountains near the capital.

Mendez and her son wore masks as they walked to the tiny roasted chicken restaurant she owns. Enrique spoke adoringly of his teacher and seemed impatient to get back to kindergarten.

Working parents have struggled to provide child care during the shutdown. It forced many to stay home from work, bring their youngsters to their jobs, or leave them at home.

Isabel Garcia had to leave her 11-year-old son, Charlie, behind while she sold vegetables below a red-domed church in San Miguel Topilejo's central plaza.

"I'm nervous about him going back to school on Monday. But he will wear a mask and I have instructed him to stay away from any children who appear sick," Garcia said as customers squeezed past her stall, a colorful tableau of radishes, carrots, green onions and other fresh produce.

This swine flu seems to have a long incubation period -- five to seven days before people notice symptoms, according to Dr. Marc-Alain Widdowson, a medical epidemiologist from the U.S. Centers for Disease Control and Prevention now tracking the flu in Mexico City. And that means the virus can keep being spread by people who won't know to stay home.

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