Those who are most at risk are: - people who have "unprotected sex" with someone who has HIV. - people who share needles, syringes or other equipment to inject drugs or medicine with someone who has HIV. - babies can potentially become infected during their mother's pregnancy, during delivery or after birth in the immediate post-partum period. they can also become infected through breastfeeding. - health care and maintenance providers who may be exposed to blood and body fluids.