What is the ruling of Islamic law regarding a husband who concealed his hepatitis virus infection from his wife, knowing the possibility of the virus transmitting to her and to her fetus, and what should she do?

If a husband conceals a contagious and repulsive disease from his wife, this is a sin and an act of harm towards her. In such a case, the wife has the right to seek annulment of the marriage contract. She retains this right unless she expresses her consent to remain with him after becoming aware of the disease.