Decline in the HIV‐1 Isolation Rate in Japan: A 12‐Year Observation

Abstract

Since 1988, we have isolated HIV‐1 from 614 HIV‐1‐infected persons (total sample = 2,785) in Japan. During the past 12 years, we have found a decline in the HIV‐1 isolation rate in Japan, with two identifiable turning points, 1991–1992 and 1996–1997. The two turning points correspond to shifts in anti‐HIV‐1 therapy. These findings suggest that HIV‐1 in Japan is currently biologically well controlled, probably due to anti‐HIV‐1 therapy. On the other hand, this decline is inconsistent with the recent increase of genetic drug‐resistant HIV‐1 in Japan. Further studies are needed to clarify mechanisms that might explain the discrepancy.