INDIANAPOLIS | Health officials closed two Indianapolis elementary schools for a week Friday after one student at each school became ill with the swine flu virus, raising the number of confirmed cases in Indiana to three.

Officials said the two youngsters are being kept at home until deemed to be non-contagious and are in "very good" condition. They said the children's illness is no worse than flu cases seen during a typical influenza season. The third confirmed case in Indiana, announced earlier in the week, was a Notre Dame student who has fully recovered.

State Health Commissioner Judy Monroe said 11 other probable cases of swine flu from Indiana were being analyzed by the Centers for Disease Control and Prevention. But she said there was no reason to panic because the nation's swine flu cases have so far been mild and comparable to cases seen during a typical flu season.

Monroe urged the public to follow health officials' advice to practice commonsense hygiene steps such as frequent hand-washing and not greeting others with handshakes to reduce the spread of the virus.

"This is a new virus and there are too many unknowns," Monroe said. "We know that influenza viruses have the capability of changing rapidly in the severity of illness. We want to take every precaution because if we limit the spread now we may well be protecting many, many people."

The school closures were the latest steps by authorities concerned about a virus that's spread to at least 19 states and is blamed for 15 deaths in Mexico and one in the United States.

State officials have banned meetings between inmates in the state's prisons and visitors to protect roughly 27,000 prisoners and 8,000 employees who live or work in confined spaces.

And Friday, Indiana University President Michael A. McRobbie announced that, in keeping with Monroe's recommendation, the school's upcoming commencement ceremonies will go on without traditional congratulatory handshakes for new graduates.

Clarian Health also announced Friday that it had restricted visitors to its three downtown Indianapolis hospitals to only parents, spouses, domestic partners and spiritual counselors to "protect everyone from unnecessary potential exposures to the virus."

Although the current swine flu cases are no worse than what's seen in a typical flu season when various strains of flu circulate, Monroe noted that each season results in about 36,000 deaths and about 200,000 hospitalizations in the United States.

Dr. Virginia Caine, the director of the Marion County Health Department, said neither elementary student who became ill with swine flu had traveled recently to either Mexico or any of the other states with confirmed cases.

She said both of those children had the illness for about a week and are faring well.

"Their health condition is very good. They have what appears to be a very mild form of influenza," Caine said.

She said she ordered the closure of the two schools -- Spring Mill Elementary School and Public School No. 60 in the Indianapolis Public Schools system -- as a precaution to prevent the virus' spread. The two schools have a combined enrollment of about 1,050.

Caine said each of the schools' students were sent home Friday at their normal time with notes explaining that the schools will be closed until May 11 and with instructions for parents and guardians.

During their weeklong holiday away from school, the students should be kept at home and not allowed to play with other children in a bid to prevent spreading the virus, she said.

"We understand this is a major step, but it's being done as a precautionary move in the best interests of the health of the children and our community," Caine said.

The children won't be readmitted to the schools until officials receive an re-entry health form stating that they are not contagious.

Parents and guardians are being asked to watch for symptoms consistent with swine flu -- including fevers over 100 degrees, vomiting, fatigue and diarrhea.

Monroe said that the state was finishing distribution to county health departments enough antiviral medication to treat 238,000 people. The state has on hand enough such antivirals to treat about 14 percent of Indiana's 6.3 million residents.

Starting by early next week, Monroe said that Indiana would begin doing its own testing for the swine flu virus, taking over for the CDC once the federal agency ships the state testing-kits to do that work. She said that so far only 6 percent of the suspected swine flu samples submitted to the state are considered to be probable swine flu that need to be sent to the CDC for confirmation.

Among the remaining samples the state's lab have received, Monroe said that 69 percent are negative for any flu virus, an indication that public health officials are "overtesting" -- which she said is fine in the current situation.

The remaining 25 percent of the samples are positive for the type of flu strains seen during a typical flu season, she said.