All perfect praise be to Allah, The Lord of The Worlds. May His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
When one of the spouses has a defect, which hinders achieving the purpose behind marriage and causes the other spouse or the offspring to contract diseases, then it is permissible to seek separation on the grounds of the harm resulting from this defect. This is because such defect prevents the spouses from enjoying each other, in addition to the fact that the resulting diseases create resentment and could be contracted by the other spouse and the offspring. In this regard, Al-Imam An-Nawawi says, "If a spouse finds that his/her spouse has a certain defect, then he/she may seek separation." {Al-Majmou`, V.16: P.268}.
Such defect is established by admission of the spouse or a certified medical report. If it was proven that the husband is inflicted with an infectious disease that causes a great deal of harm to the wife, then she may seek separation through a Sharia court.
Article No. (131) of the Jordanian Civil Status Code states, "If the wife found out, before or after the consummation of marriage, that her husband is has a defect or a disease, such as leprosy, tuberculosis, syphilis or AIDS, or he got inflicted with such illnesses and diseases during marriage, then she may go to Sharia court to seek separation. After consulting medical experts, the Sharia judge rules for immediate separation in case it was most probable that the husband can`t be cured. But, if it was most probable that the husband can be cured or the illness can go away, then he delays the separation for one year. In addition, if it hasn`t gone during this period, the husband refused to divorce her and she insisted on separation, then the judge rules in her favor. However, it is worth reminding that a defect such as the husband being blind or having a limp isn`t valid ground for separation."
On the other hand, if the wife chose to stay with her husband, then she isn`t considered sinful for not making love to him if she could be harmed by his being ill and avoiding that harm wasn`t possible. This is because the Messenger of Allah says, "There should be neither harming nor reciprocating harm." {Reported by Imam Ahmad}. And Allah the Almighty knows best.