LACK OF EVIDENCE FOR THE TRANSMISSION OF JC POLYOMAVIRUS BETWEEN HUMAN-POPULATIONS

Human polyomavirus JC virus (JCV), the causative agent of progressive multifocal leukoencephalopathy, is ubiquitous in humans, infecting chi ldren asymptomatically then persisting in renal tissue. Since JCV DNA can readily be detected from urine, it should be a useful tool with wh ich to study the mode of virus transmission in humans. Based on this n otion, we examined the extent to which JCV was transmitted from the Am erican to Japanese populations in Okinawa Island, Japan. (A population of about 50 000 American soldiers and families have been stationed in Okinawa since 1945.) Four JCV types (A to D) were identified in Ameri can populations in U.S.A., whereas only type B was prevalent in elder Japanese in Okinawa who had reached adulthood by 1945. Thus, types A, C, and D served as indicators of the transmission of JCV from American to Japanese populations. We then examined whether types A, C, and D w ere detectable in Japanese in Okinawa aged 30-50 years who may have be en in contact with Americans during childhood. However, all the 125 is olates from the younger Japanese population were type B without except ion. From this finding, we concluded that JCV is rarely transmitted be tween human populations.