ATLANTA: Federal health officials say a woman appears to have contracted the AIDS virus after deep kissing her male partner, the first reported case of H.I.V. transmission through this form of contact. In its weekly report, the Centers for Disease Control said bleeding gums, not saliva, were the most likely cause of the infection. Both the man and woman suffered from gum disease, an affliction which often causes bleeding around the teeth. CDC officials believe exposure to saliva was not the cause for a variety of reasons. Primarily, they say, certain substances in saliva tend to inhibit the AIDS virus. Although the mixing of blood after kissing appears to be the way the woman was infected, health officials could not completely rule out the possibility the virus was spread through oral sex, vaginal intercourse or other forms of contact. The agency, which has long recommended against deep kissing an infected individual, said it had not issued warnings about kissing between partners of unknown H.I.V. status because the possibility of such a transmission was remote. That policy is changing, however, as some doctors at the CDC are now recommending that those who do not know the infection status of people they have kissed obtain an H.I.V. test.