Swine Flu Fears Close Schools in N.Y., Texas, Calif.

New York

Esti Lamonaca's illness started with a high fever, a cough and achy bones, just a couple of days after she returned from a spring break trip on the beach in Cancun with friends. By the weekend, her voice was hoarse and she was wearing a surgical mask.

The 18-year-old senior is one of at least eight students at her New York City high school who health officials say have been sickened by a strain of swine flu suspected in a deadly outbreak in Mexico. It has now spread to the United States, where authorities have confirmed 20 cases.

However, all of those sickened in the U.S. have recovered or are recovering. That's a stark difference from the outbreak in Mexico that...