SAN DIEGO -- A 5-year-old South Bay girl with no pre-existing medical conditions became the 24th San Diego County resident to die of the H1N1 virus this year, the San Diego County Health and Human Services Agency announced Wednesday.

The kindergartner identified as Alitza Ortiz-Sanchez who attended Howard Pence Elementary School in Otay Mesa died Saturday at Rady Children's Hospital, said Dr. Wilma Wooten, the county public health officer.

Ortiz-Sanchez was sick for 48 hours before she went to the emergency room, where she died within an hour, Wooten said.

Dr. John Bradley, an infectious diseases specialist at the hospital, said she was much sicker than most patients when she came to the hospital.

She cried, passed out, and her heart stopped, Bradley said. Doctors were able to resuscitate her, but her heart kept stopping, the doctor said.

"Her heart just wasn't going to work anymore," Bradley said. "This was a very tragic occurrence."

That she was one of the rare H1N1 fatalities not associated with a pre-existing medical condition was not noteworthy, according to Bradley.

Bradley said the girl simply had a severe infection that attacked her heart, something he sees annually with the seasonal flu.

According to Dr. Carol Parish, superintendent of the South Bay Unified School District, the school found out about the child's cause of death Wednesday afternoon.

Parish said the school was sanitized over the two-week break, and that cleaning was routine in light of the current flu threat. The last day of school before the break was Sept. 25.

Wooten encouraged parents to keep home from school children who display influenza-like symptoms similar to the seasonal flu, including fever, cough, sore throat, body aches, headache, chills and fatigue.

Schools should send students home who develop such an illness. The same rules also should be applied to workers and their employers, she said.

It's recommended that patients remain home for 24 hours after the fever dissipates without the use of medication.

People with underlying medical conditions who experience such illness should contact their primary care physician quickly.

The H1N1 virus has disproportionately hit the younger population, according to Wooten.

"This is a wakeup call for parents to get their children vaccinated," Wooten said. "We expect and anticipate more deaths will occur, not just H1N1 but seasonal flu."

To date, 332 people have been hospitalized in the county because of the virus -- 12 more than were announced at a Board of Supervisors meeting this week, which reflected totals through Monday.

Wooten told board members that more than 700 health providers and organizations in San Diego County have ordered the vaccine, including retail pharmacies and large employers. Many school districts are also becoming involved in swine flu vaccination efforts, she said.

Priorities for vaccination are pregnant women, people who have regular contact with infants under 6 months old, health care and emergency medical workers, youths up to age 24, and adults with existing medical conditions, Wooten said.

There will be enough vaccine for people who want to be inoculated, she said.

Three non-residents have also died of H1N1 in San Diego County, according to the county Heath and Human Services Agency.

If you have received any notificiation of H1N1/swine flu at your child's school, notify 10News at kgtv_assignmentdesk@10news.com or use the News Tips form on the 10News.com homepage.