Health and Human Services Secretary Louis Sullivan has endorsed a proposal to drop infection with the AIDS virus from the list of diseases that may keep travelers and immigrants out of the United States.

But no final decision has been made on the matter because Sullivan's agency still must get comments from the State and Justice departments, said the official who disclosed the action Thursday night.Sullivan's action was made possible by last fall's immigration bill, which reversed 1987 legislation making infection with the human immunodeficiency virus, or HIV, which causes AIDS, automatic grounds for exclusion from the United States.

The immigration bill left to the secretary the decision of whether to drop HIV infection from the list of more than 30 diseases that bar entry to the country. The list includes syphilis, tuberculosis and Hansen's disease or leprosy.

Everybody with AIDS is by definition infected with HIV, but many people infected with HIV do not have AIDS, though they likely will develop it eventually.

The virus is transmitted generally through sexual contact or use of infected blood.

Sullivan has said he saw no reason to exclude people from the United States because of the AIDS virus, and his action Thursday had been expected.

The issue became controversial last year, when organizers of the international conference on AIDS held in San Francisco learned of the 1987 exclusionary provisions.

The Immigration and Naturalization Service twice acted to dilute the exclusion. It announced the availability of a 30-day waiver for people with HIV to attend conferences, get medical treatment or visit family members, and it developed a new 10-day visa for people attending scientific conferences that did not require any statement of infection.

Nevertheless, conference organizers were outraged. The International AIDS Society, the conference sponsor, said it would hold no more such meetings in the United States if the provisions remained on the books.