There have been six "probable" cases of viral meningitis in Fairfax County in the past two weeks, Health Director Gloria Addo-Ayensu reported yesterday, and follow-up tests are being conducted in 11 other possible cases, she said.

In two of the six individuals, the virus has been identified as an enterovirus, a fairly common bug, but in the others, the cause remains a mystery, the health director said.

Addo-Ayensu has previously disclosed where three of the six individuals live, but yesterday she cited patient confidentiality rules and declined to provide any information about the others.

She added that although she had information about the new cases Friday, she did not release it until yesterday because there is no requirement to report viral meningitis.

The disease rarely kills, she said, and is common this time of year. "It does not demand a case-by-case follow-up," she said.

Given that there has been a fatality and at least four cases have been in the Chantilly and Reston areas, the slow release of information has been troubling to some parents and county officials.

Two Chantilly High School students have been stricken, one fatally. Two elementary school teachers, one of them a substitute, also have had the illness diagnosed. Addo-Ayensu would not say whether the substitute teacher, who came forward over the weekend and was hospitalized in Maryland, is counted among the six cases.

Yesterday, several parents and officials said they were unhappy that the Health Department has not been more forthcoming.

"I'm very concerned about reports that sufficient information was not released or made available as soon as it was discovered," said Supervisor Sharon S. Bulova (D-Braddock), vice chairman of the board. "But my experience with Dr. Ayensu has been very positive with other issues such as West Nile virus, so I'm very puzzled by what sounds like a lapse."

Carrie Edwards, whose daughter was the second Chantilly High School 16-year-old to be hospitalized for viral meningitis this month, said she questions whether the Health Department could handle a bigger threat, such as bioterrorism.

"How bad do things have to get from that kind of standpoint before they are going to say anything?" she said. "To have a Health Department of a million people to say, 'It's at our discretion when we release information,' it does not sit well. . . . They are responsible to the citizens who pay for their jobs and may want to look very hard at how they handle sensitive and highly inflammatory issues."

Addo-Ayensu, however, said that the amount of interest in viral meningitis might be unwarranted. "We shouldn't even be reporting [cases] . . . We did this because of intense media interest," she said. But viral meningitis, she added, "is not a public health threat."

Interest in the disease began when the Health Department announced that Courtney "Kay" Richard, 16, died from it June 17.

Yesterday, Addo-Ayensu cited patient confidentiality laws for her refusal to reveal any information about where the new cases of viral meningitis emerged. "We don't give specifics as to the gender and age and where a person lives on any cases we investigate," she said.

But in a written statement June 18, the department did provide some information: "A 16-year-old Chantilly high school student died . . . and another 16-year-old Chantilly high school student is hospitalized" with symptoms of meningitis. Two days later, it released a statement saying "an Armstrong Elementary schoolteacher is also hospitalized with viral meningitis."

Edwards, who along with other parents and school officials has complained about the dearth of facts from the county Health Department, said it is important to have as much information as possible.

"If you have concerning issues, let's hear them," Edwards added. "We are responsible; we are grown up, but we want to know."

Fairfax Health Director Gloria Addo-Ayensu says reporting viral meningitis cases is not required.