A 27-year-old man with swine flu is in critical condition in a Philadelphia hospital, Gov. Rendell said yesterday as the number of confirmed cases rose sharply statewide.

Speaking one day after the first Pennsylvania death from the novel H1N1 influenza, Rendell sought to allay the public's concerns. The strain is highly treatable, he said, and the state has millions of doses of antiviral medication available for people who need it.

Of the Philadelphia patient, Rendell said, "His biggest problem was not getting to the doctor in time."

A state Health Department spokeswoman said the rise in confirmed cases overnight - from 269 to 361 - mainly reflected more illness beyond Southeastern Pennsylvania, where it had been concentrated for several weeks.

"It appears the virus is migrating, with more cases in the south-central part of the state," said Stacey Kriedeman, a spokeswoman for the Pennsylvania Department of Health. Kriedeman said four people had been hospitalized to date, including one still hospitalized - no more information was available - and one who died Thursday.

Rendell, speaking at a news conference in Pittsburgh, said the 55-year-old Berks County woman who died had been suffering from diabetes and asthma.

Most of the 27 other people nationwide who had died of swine flu-related causes through yesterday also had underlying health conditions, as do a large portion of the estimated 36,000 Americans who die every year from seasonal flu.

Federal health officials yesterday reported 13,217 laboratory-confirmed cases of swine flu. Like the seasonal flu, however, most people who are infected do not see a doctor, let alone have a specimen sent to a lab, and estimates of infected people run into the hundreds of thousands.

The highest number of confirmed cases in Pennsylvania was 80 in Berks County, where a team of epidemiologists has been vigilant about collecting specimens as part of its study of an outbreak last month at an elementary school west of Reading.

There were 70 in Philadelphia, 18 in Montgomery County, 16 in Bucks County, 15 in Delaware County, and eight in Chester County.

In York County, where confirmed cases nearly tripled to 17 in one day, the School District of the City of York announced yesterday that all of its elementary schools had been closed for the remainder of the school year due to flu concerns.

No deaths have been reported in New Jersey, whose 157 confirmed cases through yesterday included nine in Burlington County - an early target of the virus that has long since been overtaken by counties up north - and nine in Camden County. No cases have been confirmed in Gloucester County.

Contact staff writer Don Sapatkin at 215-854-2617 or dsapatkin@phillynews.com.

This article includes information from the Pittsburgh Post-Gazette.