San Mateo County health officials are reporting California's ninth death from swine flu.

The county health department said Monday that a middle-aged woman with underlying health problems had died after contracting the H1N1 flu. Health officer Scott Morrow reminded residents of the county, which has 31 of the 1,076 cases reported statewide, to avoid large gatherings of people.

California health officials had tallied 99 hospitalizations and eight deaths from swine flu as of June 18.

Half of the deaths have been in the San Francisco Bay area, half in Southern California.