The statement that follows expands and updates the previous one, based on knowledge and experience gained in the last 2 years, evolution of professional and public attitudes and beliefs, and recognition of unmet needs. Particular issues emphasized include an explicit acknowledgment of the ethical imperative to care for all patients; recognition of the low but definite risk for transmission of human immunodeficiency virus (HIV) in the health care setting and of the need for observation of universal precautions to minimize this risk; expanded recommendations for routine testing of high-risk patients; recognition of the other ethical duties that may conflict with the need for confidentiality; and recognition of a national leadership gap in public education and public policy development. The American College of Physicians and the Infectious Diseases Society of America believe that physicians, other health care professionals, and hospitals are obligated to provide competent and humane care to all patients, including patients with AIDS and AIDS-related conditions as well as HIV-infected patients with unrelated medical problems. The denial of appropriate care to patients for any reason is unethical. Physicians and other health care professionals are urged to become fully aware of potential risks and problems encountered in caring for HIV-positive patients and patients with AIDS and to take appropriate steps to minimize them. Such problems include the risk of HIV transmission, economic problems, and personal psychology stresses. Elected leaders, employers, community service organizations, welfare agencies, public housing authorities, prison officials, and school officials are urged to become fully informed and to educate others about HIV infection, and particularly to understand the limited mechanisms by which the virus can be transmitted. Dissemination of such knowledge should serve to guide public policy development, to alleviate discrimination against those who become infected with the virus, and to limit the further spread of infection. Testing for HIV antibody should be used only when it will benefit the patient or contacts to whom the virus may have been transmitted, or for protection of the public health. Counseling and educational efforts, rather than policies promoting physical restriction or quarantine, are appropriate methods for controlling the spread of HIV infection. The confidentiality of patients infected with HIV should be protected to the greatest extent possible, consistent with the duty to protect others and to protect the public health. The American College of Physicians and the Infectious Diseases Society of America encourage continued research into the causes, prevention, and treatment of AIDS and AIDS-related conditions. In addition to biomedical aspects, research into psychosocial and economic issues related to AIDS should be increased. Studies of the effectiveness of various types of educational interventions on behavior modification are critically important.