MILPITAS -- Three confirmed cases of swine flu at the Elmwood jail has spurred authorities to restrict visiting and access to three cell blocks while instituting a series of health measures to prevent further spread of the virus that has caused more than a dozen deaths in the Bay Area this season.

The Santa Clara County Sheriff's Office confirmed Tuesday that three inmates at the lower-security holding facility in Milpitas are ill with the H1N1 virus, commonly known as swine flu. The infections, the first of which was reported Friday, affect two male dormitories and one female dormitory. Sgt. Kurtis Stenderup, a spokesman for the agency, said jail staff were also dealing with at least four other suspected cases.

Since the beginning of flu season in October, the nine Bay Area counties and Santa Cruz County have recorded at least 17 flu deaths, four of them in Santa Clara, which is the highest individual county total. The bulk of those deaths have been reported since the beginning of the year.

Solano County on Tuesday reported its first flu death.

With a single-dorm capacity of 64, nearly 200 Elmwood inmates have been exposed to the virus. Stenderup said the jail was taking a multitude of health-safety measures but do not plan to seal off the affected areas.

"We're not up to quarantine status, but we're trying to take precautions to reduce unnecessary exposure to staff, inmates and the community," he said.

Among those precautions has been to cancel visiting through Friday for the A and D dorms in the M8 men's building, and the D dorm in the W2 women's building. Inmates in those areas are undergoing daily health screenings by jail medical staff and the infected are receiving treatment, Stenderup said.

Access to the dorms is limited to essential personnel, which includes jail staff, law-enforcement personnel and inmate attorneys. They are being provided with masks and gloves and are being advised of the risks of visiting the cells.

Stenderup said inmates cannot be compelled to wear masks if they refuse. Inmate transport between affected and unaffected dorms has been restricted to "essential movements," which essentially cover extraordinary circumstances.

Flu shots are among the first services offered to inmates upon booking, but they're only administered with consent. Stenderup said in light of the swine flu cases, inmates who initially refused the shots are being reminded of their availability.

H1N1 appears to be the predominant strain this flu season, causing concern because unlike other strains it can result in deadly pneumonia even in young, healthy people.

Contact Robert Salonga at 408-920-5002. Follow him at Twitter.com/robertsalonga.