The District of Columbia has two probable cases of Legionnaire's Disease, according to Dr. Martin Levy, chief of communicable disease control of the District.

The two cases - one reported at George Washington University Hospital and other at the Washington Hospital Center - appeared unrelated, Levy said. According to figures kept by the Center for Disease Control in Atlanta, the District of Columbia has reported five cases, including two deaths, since the disease was first identified in 1976.

Levy said the two cases are "probably the sporadic type of outbreak one would expect at this time of year." Levy said he would be more concerned about the two cases if they were found to be related or if a larger number were reported.

In both cases, the patients are male and both are reported to be seriously ill.

Levy noted that Legionnaire's disease - a form of bacterial pneumonia - existed before it was diagnosed and named and had caused illness and some fatalities.

An official of George Washington University Hospital, who confirmed that it had a probable case of Legionnaire's disease, said, "It's a ubiquitous disease, all the way from very mild to fatal. This looks like a very isolated case."

Levy said he heard about the case of George Washington only yesterday afternoon and did not yet have all the details.

Legionnaire's disease was first diagnosed after 29 persons attending an American Legion convention in Philadelphia died from a then-mysterious cause. Another 162 persons at the convention became ill with similar symptoms. Since that time, a number of cases have been reported around the country and abroad. Physicians have reported some success in treating the disease with an antibiotic, Erythromy cin.