Heterosexually acquired CRF01_AE/B recombinant HIV type 1 found in Thailand.

CRF01_AE and subtype B are circulating in Thailand and the strains have become intermixed in some high-risk groups, establishing the possibility of intersubtype recombination. The first such recombinant, mostly B with gp120 from CRF01_AE, was recently identified. Here we report a heterosexually acquired recombinant of different structure, with most of the genome from CRF01_AE but almost the entire envelope from subtype B. Surveillance by V3 serotype and genotype in multiple regions, followed by full-genome sequencing, was used to identify this strain. Pending vaccine trials in Thailand require knowledge of the presence of such strains in the population, and these recombinants provide valuable reagents for the laboratory evaluation of cross-subtype immunity. Studies are underway to determine whether either recombinant is circulating widely.