May 19 (Bloomberg) -- Boston Latin School, the oldest school in the U.S., and Horace Mann School, a private academy in New York, are among more than two dozen schools in the U.S. that were shut today or will close tomorrow because of outbreaks of disease.

Boston Latin, founded in 1635, will shut, starting tomorrow, and is expected to reopen May 27 after “unusually high levels of influenza-like illness,” Carol Johnson, superintendent of the Boston Public Schools, said in a statement today. Horace Mann, in the Bronx borough of New York City, will close tomorrow until May 26, the institution said on its Web site. Neither school has confirmed cases of swine flu.

Three more schools will close in New York City beginning tomorrow, two in the borough of Queens and one in Manhattan, because of influenza-like illness, the city’s health department said late today in an e-mailed statement. Nineteen schools have been shut in the city since May 14, according to the statement. At the peak of the swine flu outbreak two weeks ago, more than 725 schools in 30 states closed. At least 9,830 people worldwide have been infected in laboratory-confirmed cases, and 79 died, according to a World Health Organization report today.

Other closed schools include Dana Hall School, an all-girls private institution in Wellesley, Massachusetts, where 90 of 500 students stayed home, and St. David’s School, an all-boys elementary school on the Upper East Side of New York City’s Manhattan borough. Dana Hall is planning to reopen May 26, according to Liza Cohen, a spokeswoman. St. David’s will reopen May 21, according to its Web site.

‘Frustrated’ Parents

School outbreaks “have been a big feature” of the H1N1 epidemic, said Anne Schuchat, interim deputy director for the Atlanta-based Centers for Disease Control and Prevention’s Science and Public Health Program, during a conference call today with reporters.

“It’s understandable that parents are frustrated and are looking for ways to protect their children from flu and other infectious illnesses,” Schuchat said. “Even if a school is closed for an extended period of time, children are still susceptible to flu if they interact with other people, some of whom might be contagious even though they don’t have symptoms.”

To contact the reporters on this story: Oliver Staley in New York at ostaley@bloomberg.net; Catherine Larkin in Washington at clarkin4@bloomberg.net.

Last Updated: May 19, 2009 21:13 EDT