A 34-year-old Marine Corps captain is being treated at Walter Reed Army Medical Center for a suspected case of rabies after a wide-ranging series of tests appeared to have eliminated any other disease that would cause his symptoms.

"I can say that we are treating a man with paralysis of the limbs and encephalitis inflammation of the brain that is compatible to a rabies-like disease," Dr. Kenneth W. Bernard said last night. "Because of the number of possible exposures to rabies , we are very concerned. I can't say it's not rabies."

Because of the strong presumption that the patient has rabies, officials have decided that "postponing" preventive treatment for doctors, nurses and others who have cared for the man since he was admitted on March 2 "would be unwise," and inoculations will be administered to those personnel today.

In addition, persons who came into contact with the captain at the Quantico Marine Base clinic and later at DeWitt Medical Center at Fort Belvoir--where he was treated before his admission to Walter Reed--may be inoculated, said Bernard, the country's leading authority on rabies and an epidemiologist at the national Centers for Disease Control in Atlanta. Officials could not say last night when the man was treated at Quantico and DeWitt.

If the man does have rabies, Bernard said, he would be the first human victim of the severe outbreak of the disease that has spread northward from the South since 1977.

Nine cases of human rabies have been reported nationwide since 1979, and all were fatal. Only three persons are known to have survived the disease, and two of those suffered considerable brain damage, medical experts said.

Bernard said it was "not at all unnatural" that the tests for rabies have not yet shown its presence. "Rabies hides in the nerves from the body's immunity system and sometimes a person may be sick for a significant amount of time before the tests comes up positive," he said. "We should expect to see some rise in antibodies by next week."

The Marine, whose identity is being withheld by military authorities for reasons of privacy, was admitted to Walter Reed with upper respiratory and neurological problems.

Because those symptoms were consistent with rabies, he was placed in isolation immediately, a medical center spokesman said.

Now semicomatose and in critical condition, the patient requires a respirator to breathe, has only limited use of his limbs, and his body temperature fluctuates widely, according to Bernard.

"All we can do is support his bodily functions ," he said.

"He is certainly in worse condition today than he was when he arrived," a Walter Reed spokesman said.

Medical authorities believe the man may have contracted rabies--which has an incubation period of 12 days to one year, with an average of about 65 days--after handling a possibly rabid raccoon while hunting near Quantico with two companions during the first week of January.

"No one was bitten," Bernard said, "but they were able to pick up the raccoon--which is very unusual in broad daylight." The man's family said he had no direct contact with the raccoon, Bernard said, adding, "unfortunately, he's not able to tell us."

Bernard said that the men wrapped the animal in heavy clothing for reasons that were not explained, and later released it. The Marine's two hunting companions already have begun the series of antirabies inoculations.

A total of 20 to 50 other persons may have to take the series of five inoculations that are given over a 28-day period. A large dose of gamma globulin is also given with the first shot, Bernard said.

Bernard stressed that there is no record of direct human-to-human transmission of rabies through saliva, but that saliva from humans who had rabies has produced the disease in mice. Another medical authority said there have been incidents in which the disease was transmitted from one human to another by a corneal transplant.

"We are looking at very specific contacts," Bernard said. "It must be contact with saliva of the man on a mucous membrane or on an open wound, one that has bled within 24 hours, or the mouth or eyes."