Officials at the Alexandria Correctional Center discovered that an inmate there suffered from acquired immune deficiency syndrome (AIDS), and removed him from the jail last week, officials said yesterday.

The case is the first reported at a Virginia jail, and one of fewer than a dozen cases detected in jails in the Washington area in the last year.

"We knew this could happen and we were ready," said Alexandria Sheriff Michael E. Norris. "But it's very hard to monitor and harder to control. So many people pass through here every day, and law enforcement officers don't get to choose their inmates."

Norris reported the case, involving a 29-year-old man who was arrested on a drug charge, to the city health department on May 6 after preliminary signs of the disease were detected in a routine examination of the prisoner by Prison Health Services Inc., which checks all prisoners entering the jail. The prisoner, whose name was not released, was isolated and his clothing destroyed. He has been released on his own recognizance and placed in a private clinic in the District.

Blood tests were given to inmates who came in close contact with the man and the results were negative. But because the incubation period can be five years or longer, tests alone are not conclusive.

As the number of AIDS cases rise rapidly in the general population -- the figure is doubling each year with more than 10,000 cases diagnosed -- correctional officials across the country are tightening health screening measures for inmates and trying to learn more about the disease, which is almost always fatal.

"This is a problem that everyone who runs a public institution is going to have to face," said Michael Hennessey, sheriff in San Fransisco, where more than two dozen AIDS cases have been detected in the jail in the last year. "It will extend far beyond what we have seen."

As of this week, Virginia has 89 reported cases of the disease, which attacks the body's immune system. Last month a prisoner in the State Penitentiary in Richmond died of the disease.

Although there are no statistics kept on the number of jail inmates with AIDS, many cities are changing the way they treat sick prisoners.

Because so little is known about the disease, corrections officials have not adopted uniform guidelines on what to do when they encounter it.

In New York, where more than 100 AIDS cases have been diagnosed in the jail system in the last year, prisoners with AIDS are housed separately in a medical facility on Rikers Island, where the city's largest jail is located.

In many other jurisdictions, including much of the metropolitan Washington area, new attention has been paid to prisoner hygiene. In the past, for instance, it was commonplace for inmates to share razors but now, because AIDS is normally passed through bodily fluids, many jails require that each person have his own razor.

In addition, corrections officers in some parts of the country have begun recently wearing special protective clothing -- much like surgical gear -- designed to protect them from known AIDS carriers.

"It hasn't completely hit us yet," said Dean Moser of the National Sheriffs Association, "but we are scrambling to let people know what we can do, what will work and how to keep calm in the jails."

In the District, where three cases were reported in jails during the last year, patients are immediately segregated. Increasingly, that is the case elsewhere.

But it's not always easy. Alexandria, for instance, has a jail that was designed in 1836, filled with nooks and crannies where it is difficult to keep inmates apart.

"This is not just a case of being aware," said Edward J. Prokop, Alexandria's chief deputy sheriff. "We did what we should have done. But with this disease that doesn't seem nearly enough."

Both prisoners and guards at the Alexandria jail are upset about the recent incident, according to jail officials, and the city health department is doing what it can to inform them that casual contact with an AIDS carrier is not dangerous.

"There are so many myths, and so much fear," said Dr. David Henderson, an epidemiologist who studies AIDS at the National Institutes of Health. "I know that workers are scared when they find that somebody they know has contracted the disease, but the evidence suggests that they should not be."

Henderson is currently conducting a study of people at NIH who are exposed to the disease on a regular basis. His results indicate that close contact is not likely to spread AIDS.