Identification of a Novel Circulating Recombinant Form (CRF33_01B) Disseminating Widely Among Various Risk Populations in Kuala Lumpur, Malaysia

Abstract

A molecular epidemiological investigation was conducted among various risk populations (n = 184) in Kuala Lumpur, Malaysia, in 2003 to 2005, on the basis of nucleotide sequences of protease and reverse transcriptase regions. In addition to circulating HIV-1 strains, including CRF01_AE (57.1%), subtype B (20.1%), and subtype C (0.5%), we detected a candidate with a new circulating recombinant form (CRF). We determined four near-full-length nucleotide sequences with identical subtype structure from epidemiologically unlinked individuals of different risk and ethnic groups. In this chimera, two short subtype B segments were inserted into the gag-RT region in a backbone of CRF01_AE. The recombinant structure was distinct from previously identified CRF15_01B in Thailand. In agreement with the current HIV nomenclature system, this constitutes a novel CRF (CRF33_01B). The overall prevalence of CRF33_01B is 19.0% (35/184). Although the prevalence of CRF33_01B is particularly high among injecting drug users (42.0%, 21/50), it is also detected in a substantial proportion of homo-/bisexual males (18.8%, 3/16) and heterosexuals (9.8%, 9/92). Moreover, unique recombinant forms composed of CRF01_AE and subtype B that have a significant structural relationship with CRF33_01B were detected in 1.6% (3/184) of study subjects, suggesting an ongoing recombination process in Malaysia. This new CRF seems to be bridging viral transmission between different risk populations in this country.

HIV-1 CRF01_AE and Subtype B Transmission Networks Crossover: A New AE/B Recombinant Identified in Japan

“…S2), which differed from any previously reported AE/B recombinant forms. [3][4][5][6][7][8][9][10][11][12][13][14] The requirement for declaring a new CRF, as proposed by the Los Alamos National Laboratory in 1999, is to have at least three cases with no direct epidemiological lineage, accompanied by near full-length sequences. 32,33 From the medical records of the cases we confirmed that K231, K320,…”

“…1,2 This area has been recognized as a ''recombination hotspot'' 1 for AE and B. To date, 13 CRFs consistent with these two subtypes have been discovered, i.e., CRF15 3 and 34 4 in Thailand; CRF33, 5 48, 6 53, 7 54, 8 and 58 9 in Malaysia; CRF52 10 in both Thailand and Malaysia; CRF51 in Singapore 11 ; and CRF55, 12 59, 13 67, and 68 14 in China. In Japan, the number of HIV/AIDS patients at the end of 2013 was 23,015, including 7,203 AIDS and 15,812 non-AIDS patients.…”

The Indonesian Variants of CRF33_01B: Near-Full Length Sequence Analysis

“…11 These CRFs originated and mostly circulated in their countries of origin. [9][10][11] Our previous study showed that CRF01_AE was the main circulating subtype in Indonesia, followed by small number of subtype B. Furthermore, we also found five samples suspected of being CRF_01B URFs.…”

“…[3][4][5] To date, 9 different subtypes and 43 CRFs have been reported. 6 In addition to the reported CRFs, numerous unique recombinant forms (URFs) were also identified worldwide, including Southeast Asia, 5,7,8 where cocirculation of subtype B and CRF01_AE as the main circulating subtypes resulted in the generation of CRFs, such as CRF15_01B, 9 CRF33_01B, 10 and CRF34_01B. 11 These CRFs originated and mostly circulated in their countries of origin.…”

“…These results raised the possibility that 07IDJKT189 and 07IDJKT194 had mosaic genomes similar to the Malaysian CRF33_01B genomes. 10 To assess this possibility, we performed bootscanning plot analysis as described previously. 15 The analysis confirmed that 07IDJKT189 and 07IDJKT194 indeed were mosaics of CRF01_AE and subtype B in Southeast Asia (subtype B 0 ) and had a mosaic pattern similar to the CRF33_01B genomes ( Fig.…”