The Viral Epidemiology Branch of the National Cancer Institute undertakes a broad range of epidemiologic studies of cancer and AIDS causing viruses with a particular emphasis on Human Immunodeficiency Virus and other oncogenic retroviruses. Many of these viruses occur in overseas locales such as the human T-cell lymphotrophic viruses type I and II. The objective of the proposed contract will be to support the research mission of the Viral Epidemiology Branch by facilitating overseas research projects whose goals are defined by Viral Epidemiology Branch staff. These studies often take place in settings where communications, and access to study populations are limited because they are in developing countries in Africa, Asia, and Central and South America. A major object of the proposed contract will be to supports these studies by facilitating access to populations, arranging for cooperation with local medical and governmental health officials. Another objective is for the contractor to insure that all clearances are obtained from appropriate Institutional Review Boards to insure that all requirements of the Office for Protection from Research Risk are fulfilled. Another objective will be for the contractor to implement research protocols originated by Viral Epidemiology Branch staff and insure that special circumstances in the local environment such as special logistical concerns, cultural sensitivities, etc are addressed. The major objective is for the contractor to implement overseas field work in a way that insures that the data and samples collected are of the highest quality for epidemiologic analysis. Another objective is for the contractor to supply NCI with data that can be analyzed by the Viral Epidemiology Branch with results of studies to be published in peer review journals. In summary the objective of this project is to conduct a series of epidemiologic studies of human retroviruses in different geographic locales to answer scientific questions concerning the role of these and other oncogenic viruses in the etiology of cancer.