SAN JOSE -- An aggressive response has contained apparently unrelated incidents of bacterial meningitis that killed a 5-year-old girl and sickened a mother and her 10-year-old son over the past week, public health officials said.

MENINGITIS Meningitis: What Is It? | FAQS Link: National Meningitis Association SYMPTOMS High fever Headache Stiff neck Nausea/Vomiting Sleepiness Confusion Source: Centers For Disease Control And Prevention

Rachel Schrette was rushed to the hospital after she developed bruises on her feet but died Christmas Day. In separate cases, the boy has recovered and his 32-year-old mother is in the hospital in good condition, said Joy Alexiou, a Santa Clara County public health spokeswoman on Monday.

It is unclear how the victims were infected, but public health officials said they have treated anyone who was exposed to them and believe the disease has not spread.

Meningococcal meningitis is an infection of the covering of the brain and spinal cord which spreads through saliva and mucus. The easiest ways to prevent the disease's spread are to cover up when coughing and sneezing and to wash hands regularly.

The three infections raise to five the number of bacterial meningitis cases in Santa Clara County this year -- down from nine last year and 10 in 2001.

In Contra Costa County, public health officials Monday announced that two high school students and one visiting college student had contracted meningitis.

One of the San Ramon Valley High School students was diagnosed with the disease on Dec. 15 and the other was diagnosed the day after Christmas. Both were receiving treatment and were expected to recover, according to Wendel Brunner, director of the county's public health department.

The third victim was diagnosed over winter break while visiting home from college and was also not suffering life-threatening symptoms. None of the three cases appear to be related, Brunner said.

The three students were diagnosed with meningococcal meningitis, which falls under the category of bacterial meningitis, according to Brunner. Meningococcal meningitis is one of the more contagious forms of the disease, and can be spread through saliva, including the sharing of food, drinks or utensils.

Normally in Contra Costa County, there are between 9 and 19 diagnosed cases of meningitis per year, Brunner said. Including the students, this year's total is 12.

Bay Area residents should not panic, but should be aware of symptoms, Brunner said.

"In the Bay Area we are experiencing what is the typical, normal amount for the wintertime," he said. "On the other hand, meningitis is a very serious disease."