The human T-cell leukemia-lymphoma virus in the southeastern United States.

The human T-cell leukemia-lymphoma virus (HTLV) is a recently described RNA tumor virus associated with human T-cell malignant neoplasms. In two geographic areas, Japan and the Caribbean basin, clusters of adult T-cell leukemia-lymphoma are "sentinel diseases" and have suggested an underlying prevalence of HTLV infection in both family members of the index cases and in the population. Four cases of lymphoma from the United States are described as illustrative of the sentinel disease. Serological studies of families and of a small population sample suggest that HTLV infection is endemic in certain parts of the southeastern United States at rates similar to those seen in Caribbean blacks but at a lower rate than that observed in southwestern Japan.