HIV is transmitted via unprotected sexual contact with an infected partner or through contact with infected blood. Rigorous screening of the blood supply and heat-treating techniques for donated blood have reduced the rate of transmission via blood transfusions to a very small percentage. However, sharing needles and/or syringes with someone who is infected is still a mode of transmission of the HIV virus. In the past, HIV was frequently passed from a mother to her baby during pregnancy and/or birth. Treatments are now available that reduce the chances of a mother passing the virus to her child to one percent.