Is it obligatory to inform the suitor of his fiancée's AIDS if she refuses to inform him?

Advising Muslims means guiding them to what is beneficial for them and wishing good for them, and it is part of the religion. Therefore, whoever knows of a flaw in a girl that a suitor is proposing to must inform him of it, especially if this flaw is a serious illness such as AIDS. This is subject to certain conditions: the advice must be given for the sake of Allah, to remove harm, not for defamation; it must be limited to what is necessary and done secretly; and the advisor must have certain knowledge, not mere conjecture.