Two eighth-grade students at a middle school in the Rockville area of Montgomery County have contracted bacterial meningitis, a serious infectious disease, county officials reported last night.

Parents of other students at Redland middle school, 6505 Muncaster Mill Rd., have been notified. Dr. Donald A. Swetter, director of the county health department, said those in contact with infected persons are usually advised to take antibiotics as a preventive measure.

Both students, who were not identified, are believed suffering from meningococcal meningitis, one of several forms of the disease. About two cases of meningococcal meningitis are reported each year for every 100,000 persons, according to the federal Centers for Disease Control in Atlanta.

Both of the infected students were reported under physicians' care.

One of them was "apparently responding quite well to medication," according to school system spokesman Bill Henry. He said no information was immediately available about the other.

Swett said both students "should recover with appropriate treatment." He said the disease, which affects the coverings of the brain and spinal cord, was a "very serious infection, but [it] responds well to antibiotics."

At least three cases of bacterial meningitis have been reported this year at a high school in Staunton, Va. The infection also has been reported this year in Lexington, Va. The winter and early spring is the most common time for the disease.

Henry said he knew of no cases of meningitis in any other county schools in at least a year.