Early diagnosis frequency and estimated HIV-1 incidence from 2006 to 2015. (A) Data on HIV-1 recent infection frequency in Tokyo, Osaka, and Fukuoka. (B) Temporal changes in the frequency of recent infections over time. (C) Estimated HIV-1 incidence from 2006 to 2015 and undiagnosed cases at the end of 2015 in Tokyo, Osaka, Fukuoka, Japan except for Tokyo, and Japan. HIV-1 incidence in Tokyo, Osaka, and Fukuoka was estimated using data from the HIV-1 recent infection assay and the HIV/AIDS national surveillance. HIV-1 incidence in Japan except for Tokyo was estimated by applying the early diagnosis frequency from Fukuoka. Estimated cases in Japan are the sum of the cases in Tokyo and in Japan except for Tokyo.