A 43-year-old Virginia man has become the first physician in the Washington region with AIDS to sue his employer for discrimination, saying that he was fired from a Fairfax County health clinic because of his illness.

The case has drawn the special attention of civil rights groups and AIDS organizations who say it illustrates how widespread and irrational the fear of AIDS has become -- even in the medical profession.

"You would like to believe that of all people, doctors would understand that AIDS is not casually transmitted," said Jim Graham, director of the Whitman-Walker Clinic, the Washington area's chief AIDS treatment center. "There is no reason for that man not to be at work."

In the lawsuit filed yesterday in U.S. District Court in Alexandria, the doctor -- who has requested that his name be withheld -- alleged that Primary Care Associates fired him even though he is willing and able to work. He said that as soon as clinic officials found out his illness was acquired immune deficiency syndrome, they told him he was unfit to carry out his duties.

"I feel like I helped build that practice from nothing," the doctor said in an interview. "I was there the day it opened. To be just cut off like this is very painful."

A spokesman for Primary Care, which operates two clinics in Northern Virginia, said there would be no comment on the suit or any of the allegations.

As the disease continues its rapid spread -- the Centers for Disease Control has received reports of 19,181 cases as of yesterday and predicted that the total will grow to 30,000 by 1987 -- the fear of contracting AIDS in the work place has emerged as a key issue associated with the fatal illness.

The Centers for Disease Control issued federal guidelines in November for health care workers with AIDS, which stated that unless there is a risk of mixing bodily fluids with patients there is no evidence the virus can be transmitted.

"Health care workers known to be infected with the AIDS virus who do not perform invasive procedures need not be restricted from work," the guidelines stated.

Last year, Virginia enacted a law that prohibits discrimination against the disabled, and gives protection to workers fired for that reason. According to the doctor's suit, the clinic considers him to be disabled and to have violated his contract. He said he was paid $88,000 for his services in 1985.

The Primary Care facility in Annandale, where the doctor worked, opened on Oct. 17, 1983. Although originally trained as a pediatrician, the doctor worked as a general practitioner until December when he became ill. He entered Fairfax Hospital and within weeks was diagnosed as having the disease.

After being released from the hospital on Jan. 15, he contacted his employers and told them he would be able to return to work by the end of February.

"They hemmed and hawed on the phone," he said. "Finally, I asked them what was going on and they said I shouldn't be in the clinic because of what was wrong with me. I was shocked to learn they found out from Fairfax Hospital. And I was shocked they would not let me return."

He said he then tried to persuade the clinic to let him perform another job, in personnel or administration. He wrote to the clinic director on Feb. 22 saying he would be willing to compromise, but on March 27, he received a reply that said he was in default of his contract.

"They stated in the letter I refused to perform my duties but that's not true -- it's an insult," he said. "I am perfectly willing and able to work. They just won't let me."