Does God forgive whoever repents from fornication that caused the transmission of AIDS to his wife and infant, and is the infection of the wife and infant with the disease considered involuntary manslaughter that necessitates expiation, and when is this expiation due, and is what befell him divine decree and destiny?

This brother must sincerely repent and increase his acts of obedience and good deeds. Allah transforms the bad deeds of those who repent into good deeds and forgives all sins. If the disease was transmitted to his wife without his knowledge, or if the virus was dormant, then there is no sin upon him. However, if he knew he was infected and had intercourse with his wife without her knowledge, this is not permissible, and he must repent, seek forgiveness, and ask for her pardon, because "there shall be no harm or reciprocating harm." Anyone who harms people is prohibited from associating with them. There is no expiation or guarantee upon him for the transmission of the disease to his wife and child, but if he intentionally caused harm to others, he is sinful and must repent, seek forgiveness, and ask for pardon from those he caused harm to.