Public health officials warned yesterday that persons who have had contact with possibly rabid animals should seek medical attention immediately, noting that by the time symptoms of the disease occur there is little hope for survival.

The warnings came after the disclosure Wednesday that a 33-year-old Marine Corps captain stationed at Quantico Marine Base has been under treatment at Walter Reed Medical Center since March 2 for a suspected case of rabies.

The man, whose identify has not been revealed, remained in critical condition yesterday, according to hospital officials. He is semiconscious, has limited movement of his limbs, suffers from encephalitis inflammation of the brain and requires a respirator to breathe, doctors said.

There have been nine human rabies case in the United States since 1979, including one in Boston and another in Ann Arbor, Mich., earlier this year. None of the victims has survived.

Officials at Walter Reed and area public health agencies said they were swamped with calls yesterday inquiring about symptoms of rabies in humans and the possibility of receiving the five-shot series of antirabies inoculations.

The series of shots, administered over a 28-day period with the first accompanied by a massive gamma globulin injection, costs between $400 and $500 and offers immunity for about three years.

Dr. Martin Levy, administrator of preventive health services for the District's Commission of Public Health, said the best preventive measure is the inoculation of cats and dogs and the avoidance of contact with wild animals.

Levy also said that two more confirmed cases of rabies in raccoons have been recorded in the District, bringing to 13 the number of raccoons in the city identified as rabid since October.

Although tests have not confirmed that the Marine captain has rabies--experts said false negative results often occur with the tests--medical authorities said that inoculations for doctors, nurses and others who have treated the man will begin this afternoon as a preventive measure. The serum for the inoculations arrived yesterday. The officials pointed out that there are no known cases of human-to-human transmission of the disease.

Rabies is transmitted to humans in the saliva of diseased animals through a bite or an open wound, mucous membranes, the eyes or the mouth.

Dr. Kenneth W. Bernard, a medical epidemiologist with the Centers for Disease Control in Atlanta and the nation's leading authority on rabies, was called into the case by Walter Reed officials. Dr. Robert Redfield heads the team of physicians who are treating the Marine. "All we can do is support his bodily functions ," Bernard said. There is no known natural immunity to the disease and no previous treatment has proved successful.

Interferon, a widely heralded, potent natural substance that attacks viruses, has been found not to be effective against the disease, Bernard said.

In addition to medical personnel at Walter Reed, Bernard is surveying those who treated the Marine at the Quantico base clinic on Feb. 16 and Feb. 26 and at DeWitt Medical Center at Fort Belvoir between Feb. 27 and March 2, when he was transferred to Walter Reed. A Quantico spokeswoman said the man complained of back and upper respiratory problems on both visits to the clinic there. She did not know the nature of the treatment administered.

Little personal information about the Marine was released yesterday. The spokeswoman at Quantico said the patient, a native of Las Vegas, has been at Quantico since July 8, 1980, and is a member of the headquarters and service battalion. Such units usually serve as the administrative and support staff for the base.

The Marine captain, who reportedly hunted extensively around Quantico and out of state, may have been exposed to a rabid raccoon the first week in January while hunting on the Quantico base with two companions, a Marine warrant officer and a staff sergeant.

The two companions--who began the series of antirabies inoculations last week--picked up a young raccoon that was wet and wrapped it in heavy clothing, according to the Quantico spokeswoman. No one was bitten and the two other Marines say the captain did not have direct contact with the raccoon.

The raccoon was later released.