EACH WEEK the Centers for Disease Control in Atlanta publish a newsletter about acquired immune deficiency syndrome (AIDS) listing the number of known active cases and grouping those cases according to the presumed reasons for contracting the disease. This week, for example, the CDC reported 9,405 current AIDS cases -- 75 percent are homosexual or bisexual males. Others, we are told, acquired the disease either from bisexuals through sexual contact or from blood transfusions or drug use involving contaminated needles.

Until this week, the CDC listed another category of high-risk AIDS victims: Haitians. They were the only ones on the list, according to Dr. Walter Dowdle, director of the CDC's Institute for Infectious Diseases, "identified because of who they were rather than what they did." Haitians in this country had always objected to this classification because it made other Americans hesitant about any contact with them and diminished their job opportunities and ability to assimilate, culturally and socially, into American society.

Everyone concedes that there is an abnormally high incidence of AIDS among Haitians -- about 3 percent of current cases. But there was disagreement over whether the disease was present because of some genetic trait or environmental factor that struck this group alone or because of some conduct by those afflicted.

The CDC, which has been studying AIDS since 1981, resisted early political pressure to remove Haitians from the high-risk group. But doctors there now believe there is no scientific reason to presume that an ethnic characteristic is a relevant factor. Haitians have been removed from the list of groups at risk -- an acknowledgment that scientists are not sure why Haitians contract AIDS at high rates. They are grouped with thse at increased risk for whom the source of the disease has not yet been determined.

Each Haitian who contracts AIDS will be studied to see if he or she fits into any of the known high- risk categories for reasons other than his nationality. As is the case with many other increased-risk cases, blood donations will not be accepted from this group as a precaution. But scientists now believe that, as is the pattern among other groups, some Haitians will contract AIDS because of known, high-risk activities, while most will not. The CDC's decision should help reduce discrimination against Haitians.