Could you tell me what are all the possible ways to contract hiv ?

See answer below: There are several ways to transmit hiv. Hiv infection is typically acquired through unprotected sex (vaginal, anal, oral), sharing infected needles such as with injection drug use, or transfusion of hiv-infected blood products. Hiv infected mothers can also transmit HIV to their child during childbirth. Less common ways include transmission via using infected tools with tattooing or piercings.