MODEL RELEASED. HIV+ mother with her child. Woman infected with HIV (human immunodeficiency virus) holds her baby. Photographed in Kigali, Rwanda. HIV attacks the immune system, leading to AIDS (acquired immune deficiency syndrome), where the person becomes highly vulnerable to further infections. An infected mother risks transmitting the virus to her baby during childbirth or breast- feeding. The risk of transmission during childbirth can be cut using anti-retroviral drugs, but they are often too expensive for people in the Third World. In 2001, a UN agency estimated that 500,000 people were living with HIV/AIDS in Rwanda.