HTLV-I is endemic in southern Italy: detection of the first infectious cluster in a white population.

Human T-cell leukemia virus (HTLV-I) infection is observed among black and Japanese populations in well-delimited endemic spots in association with a high incidence of adult T-cell leukemia (ATL). We present evidence of HTLV-I infection in two ATL patients from southeastern Italy who have not travelled and who have no known relations abroad, and in 8% of non-leukemic controls from the same area. Thus, populations exhibiting HTLV-I infection appear more widespread than supposed up to now.