This briefing paper focuses on children ages birth to five years and is intended primarily for health workers in developing countries who are responsible for the management of young children with HIV and AIDS. It provides practical information on: (1) how HIV is transmitted to infants and young children; (2) how transmission can be prevented; (3) how to diagnose HIV and AIDS in young children; (4) how to care for children with HIV, including treatment of common infections; (5) how to provide support to families caring for sick children; (6) how children who are not infected may be affected by HIV; and (7) how HIV and AIDS in children affects health workers and other caregivers. Other important issues related to HIV/AIDS and children that health workers need to be aware of are also addressed, including community support, orphans, sexual abuse, and HIV testing and counseling. A list of selected printed and organizational resources on AIDS and children is included, along with a glossary of relevant terms. Appendices include a fact sheet on HIV and AIDS and an outline of a workshop and exercises that may be helpful in educating health workers about HIV/AIDS and children. (CR)