en General General Original Research Original Research Human T-ceil lymphotropic virus, type 1 (HTL V-I) is considered to be the causative agent of adult T-cell lymphoma/leukemia and spastic paralysis, and seems to be common in Khorasan Province. 300 blood samples from Mashhadi and 180 from Gonbadi blood donors were obtained (all samples from healthy subjects). Serological screening was done by passive particJe- agglutination test and confirmed by Western blot test. 10% of Mashhadi and 3.3% of Gonbadi residents were positive for HTLV-1 antibodies. Our findings suggest that Mashhad may be within a previouslyunrecognised endemic region for HTL V-I which may be a major health problem for Khorasan Province. 85 86 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-685&slc_lang=en&sid=1 R FARID 20031947532846006282 20031947532846006282 Yes Mashhad University of Medical Sciences, Mashhad. Iran MM ETEMADI 20031947532846006283 20031947532846006283 No Mashhad University of Medical Sciences, Mashhad. Iran H BARADARAN 20031947532846006284 20031947532846006284 No Mashhad University of Medical Sciences, Mashhad. Iran A SHIRDEL 20031947532846006285 20031947532846006285 No Mashhad University of Medical Sciences, Mashhad. Iran N AHKAMI 20031947532846006286 20031947532846006286 No Cornell University Medical Center, New York, U.S.A., S SAFAI 20031947532846006287 20031947532846006287 No New Jersey University Medical School, N.J., U.S.A.