A Federal recommendation to exclude certain Haitians from blood donations as a safeguard against spreading AIDS has been expanded to all Haitians, and the change is being protested by Haitian organizations in New York City and Miami.

The policy change was issued last month by the Food and Drug Administration, which has a role in overseeing the nation's blood supply. The agency's recommendation is not binding, but local blood banks are complying as a precaution.

Leaders of Haitian-American organizations, who say there are 150,000 Haitian immigrants and their relatives in the Miami area and 350,000 in the New York area, say the policy is irrational because Haitians are no more likely to carry the AIDS virus than some other groups. The Haitian-American leaders also say the move will revive the stigma and bias that afflicted Haitians when the Federal Centers for Disease Control initially listed them as a high-risk group. That classification was later modified.

The F.D.A. based its recommendation on the fact that for Haitians the primary route for AIDS transmission is through heterosexual intercourse, making it more difficult to identify people at high risk of AIDS. Officials point out that most people with AIDS who were born in the United States were infected through homosexual intercourse or drug abuse and know they should not donate blood.

Discussions Are Scheduled

An F.D.A. advisory committee has agreed to meet with Haitians' representatives, probably next month, according to an agency official who spoke on the condition of anonymity.

Growing heat over this issue prompted a march of more than 5,000 Haitian-Americans outside an F.D.A office in Miami last week, snarling Miami International Airport traffic. ''Racists!'' the crowd chanted. The rally was organized by the Haitian Coalition for Health, an alliance of Haitian groups in surrounding Dade, Palm Beach and Broward Counties.

The policy on protecting the blood supply against the AIDS virus has evolved over the years. It excludes several groups from donating, including men who have ever had sexual relations with other men, prostitutes and their customers, users of intravenous drugs, and the sexual partners of anyone in these groups.

In 1983, the agency recommended banning blood donations from people who emigrated from Haiti after 1977, the year the epidemic is believed to have started. In 1986, donations from immigrants who came to the United States from Central Africa were also excluded, since AIDS was spreading rapidly there.

Then It Was the Sub-Sahara

In 1988, no one from any part of the sub-Sahara was allowed to give blood.

The latest change, officially adopted Feb. 5, eliminated the 1977 time limit for Haitians. Thus the new policy bars blood donations from all Haitians and sub-Saharan Africans in this country, regardless of when they immigrated. The change was made because of uncertainty over the use of the 1977 cutoff, given the frequent lag from infection with the AIDS virus to symptoms.

In both Haiti and the sub-Sahara, AIDS appears to be predominantly spread among heterosexuals, with roughly equal incidence among men and women. In the United States and Europe, the epidemic has been mostly among homosexual and bisexual men and intravenous drug users, and some cases among their heterosexual sex partners and babies.

Tracing the Virus's Habits

Medical scientists now say that the virus began spreading in different groups in different countries; that there may be more bisexual men in Haiti; that Africans and Haitians may have more sexually transmitted diseases that hasten the spread of AIDS; that African heterosexuals may have more sex partners; that prostitution may be more common, and that the lack of circumcision may promote transmission.

The vast majority of Haitians have neither the disease nor the virus. But advocates say fear of AIDS and stereotyping of have brought discrimination against Haitians.

Haitian domestic workers in the New York City suburbs have been summarily dismissed, said Joseph Etienne, executive director of the Haitian Centers Council in Brooklyn, a coalition of eight groups. ''In a public high school in Brooklyn, after a 10-year-old Haitian girl used a telephone, they sprayed it,'' he said.

Unfair, Advocates Say

Louis Germain, assistant director of the Haitian-American Community Association of Dade County, said: ''People have lost their jobs, and Haitian students are being stereotyped. Last week a teacher in a class on AIDS told the students if they don't want to get AIDS they have to remain free from drugs and homosexuality and stay away from Haitians.''

Spokesmen for Haitian groups argue that the Food and Drug Administrationn's blood policy unfairly singles out their nationality when other groups, including black and Hispanic Americans in several major cities, actually have a higher rate of AIDS.

''They have not been excluded from giving blood,'' Mr. Germain said. ''It's illogical and discriminatory to exclude Haitians.''

Mr. Etienne said he feared that ''this hasty decision will have a long negative impact on Haitian people.''

Dr. Warren D. Johnson, a physician at New York Hospital who has studied AIDS in Haiti, said it was illogical to single out Haitians. He added that other Caribbean nations, including the Bahamas and Jamaica, are beginning to show some heterosexual spreading of AIDS.

The American Red Cross processes about half the nation's blood supply. Dr. S. Gerald Sandler, its medical director for blood services, said the potential for discrimination because of the policy ''is a great concern to us'' but added. ''I hope all persons affected by the change will understand our position.''

The agency screens all donations for antibodies to the AIDS virus - as a sign of infection - and those testing positive are discarded. But it takes weeks, months or years before infected people produce antibodies. So proponents say excluding donations from high-risk groups reduces the possibility that an infected donation might slip by the antibody test.

A Message in Statistics

The Centers for Disease Control have stopped publicly specifying that Haitians are at risk for contracting AIDS, but the agency's statistics still carry a category of ''pattern II countries,'' where heterosexual intercourse is the primary mode of infection. And these are defined by the World Health Organization as Haiti and sub-Saharan Africa.

As of the end of January, the United States had recorded 121,645 AIDS cases, and of those, 1,962 were immigrants from Haiti and the African countries, their sex partners or their babies. And most of those infected were Haitians.

In New York City, as of Feb. 2, there were about 550 Haitian-related AIDS cases among the city's total of 24,383 cases.