Differential Prevalence of HIV Type 1 Subtype B and CRF01_AE among Different Sexual Transmission Groups in Tokyo, Japan, as Revealed by Subtype-Specific PCR

Abstract

We determined the subtype of HIV-1 in 89 infected individuals attending three reference hospitals located in the Tokyo metropolitan area of Japan. Subtyping was performed with subtype-specific polymerase chain re-action (PCR) distinguishing subtype A, B, C, and CRF01_AE and/or phylogenetic analysis of HIV-1 env C2V3C3 sequences. Subtype-specific PCR provided unequivocal results in 97% of samples. Sixty-five subjects were infected with subtype B, 16 with CRFO1_AE, 4 with subtype A, 1 with CRF02_AG, and 3 with subtype C. Among 31 Japanese individuals infected through heterosexual contact, 13 were infected with subtype Band 12 with CRFO1_AE. All of the 41 Japanese men infected through homosexual contact harbored subtype B. These results indicate that subtype B is exclusively predominant in a homosexually transmitted group, whereas subtype B and CRFO1_AE are evenly predominant in a heterosexually transmitted group.

Non-B HIV Type 1 Subtypes among Men Who Have Sex with Men in Rome, Italy

“…This is consistent with the geographic distribution of subtype A, which is widespread in both Eastern Europe, in particular in the former USSR, [41][42][43] Balkan countries such as Albania, 44 and in Southeast Asia. [45][46][47] The two sequences detected in Italian individuals, identified as A pure subtype, are closely related to the sequences from Balkan countries and cluster with different clades that are genetically distant; as expected, the sequence detected in the MSM from the Ukraine was similar to the representative strain; thus her infection could have been acquired in the Ukraine or from an infected individuals from this country.…”

Emergence in Japan of an HIV-1 Variant Associated with Transmission among Men Who Have Sex with Men (MSM) in China: First Indication of the International Dissemination of the Chinese MSM Lineage

“…HIV-1 epidemics among MSM in major cities in the United States and Europe were first detected in the early 1980s (14); for these epidemics, subtype B was the responsible founder strain (14) and is also commonly found in most developed countries in the Asia-Pacific region, including Japan. According to Kato et al, who studied samples collected in February 1998 to March 2002 in Tokyo, subtype B was almost the only HIV-1 strain identified among MSM in Japan (15). A recent survey, however, began to detect a small number of CRF01_AE infections, as well as CRF01_AE/subtype B discordant strains or recombinants (the present study).…”

Genetic Analysis of HIV-1 in Japan: a Comprehensive Analysis of Donated Blood

“…Although subtype B was mainly detected among men who had sex with other men (MSM), CRF01_AE was circulating mostly among heterosexuals throughout Asia, including Japan (29,(39)(40)(41). According to the annual reports released by the National AIDS Surveillance program (37) OMPD is a measure of genetic diversity, and the OMPDs of CRF01_AE isolates were higher among more recent isolates as compared with that observed in earlier isolates, indicating that earlier CRF01_AE isolates were more similar to each other than were recent isolates.…”

“…Data on HIV-1 infection are submitted to the National AIDS Surveillance database, and these data include information regarding HIV-1-positive blood donations. To understand the distribution of HIV subtypes in Japan, epidemiological studies of samples collected by hospitals or health centers in specific geographic regions are conducted continuously (25)(26)(27)(28)(29). According to the National AIDS Surveillance database, about 10z of new HIV-1 infections are identified among blood donors in Japan.…”