Arlington's public health chief told the School Board last night that the county has the highest number of AIDS cases in Virginia, but he stressed that the deadly disease is nowhere near epidemic proportion.

Martin P. Wasserman, appearing before the board for a routine informational briefing on acquired immune deficiency syndrome, said 40 of the 160 cases reported in Virginia since 1981 are in Arlington. Most of the county's victims are male homosexuals, the disease's biggest risk group, Wasserman said.

None is either a student or a school employe, Wasserman said after the briefing.

"The situation is not out of control or anywhere near epidemic proportions," said Wasserman, director of the county's Department of Human Services.

Last week, a clinic that serves the Washington area's homosexual population reported that the metropolitan area, with 475 reported cases, has the sixth largest concentration of AIDS cases in the nation.

Arlington does not have a special policy for treating AIDS victims in the schools. Board Chairman Gail H. Nuckols said a general state policy on communicable diseases is being followed and that it excludes persons with such diseases from school until they are evaluated on a case-by-case basis. The same policy is followed by Alexandria. Prince George's County and the District have similar policies.

School officials in Fairfax and Montgomery counties have tentatively adopted policies excluding AIDS victims.

"At this point, we haven't made any determination that we need anything further" than the general state policy, Nuckols said. " . . . One of the problems is the disease itself, and the other is the public perception of the implications of the disease. Both have to be dealt with."

Wasserman, emphasized the need to avoid hysteria over AIDS. He said it is not casually transmitted and that both the CDC and Virginia health officials advise that schools conduct case-by-case reviews of school-age victims, rather than barring them from school as a general policy.

In other action, the board adopted a policy endorsing the concept of regularly assigned homework, with frequency and amount determined by teachers.