An infection of the gum can, in fact, be passed on to another person through the saliva. If you had an infection when you kissed this person when you still had the infection then yes, there is a very good chance that you have passed it on to him. However, there are certain things that you should consider. First of all you are assuming that the gum infection had not cleared by the time you kissed this man. If you were on antibiotics and took your course of medication, it is more than likely that your infection had completely cleared up. If that is the case, then there is no need to worry about the possibility of having passed on the infection to someone whom you kissed.
Other factors to be kept in mind are the health of the person whom you kissed. Although gum infections are contagious and do travel from one person to another, transmitted by the saliva, what is important is how often you kissed this person. Kissing once will not cause the infection to pass on to him. Even if you have kissed this man several times, you should also consider his own health. Transmission of an infection does not depend on the person passing it on alone. It also depends on the person to whom you believe you have passed on the infection. If the person is weak and his immunity is low, then there are chances that he had got the infection from you, when you kissed him. But if the man you kissed is not easily susceptible to infections, then it is more than likely that unless you kissed him regularly over a period of time, you did not actually pass on the infection to him. You should remember that since an infection of the gum is caused by a specific bacterium, there is a very good chance of bacterial contamination of another person through saliva. However, there are some people who only remain carriers of the disease. That is, even after they come intimately in touch with someone who has the infection, these people become mere carriers. That is, they carry the disease but don't suffer from it themselves. So, if the person whom you kissed and about whom you are worrying is a carrier for this infection, then it is more than likely that he is a carrier for the bacteria but has not himself suffered from it.
answered by G M