Kenneth Siu-Sing Leung, Sabrina Wai-Chi To, Jonathan Hon-Kwan Chen, Gilman Kit-Hang Siu, Kenny Chi-Wai Chan and Wing-Cheong Yam* Pages 53 - 64 ( 12 )
Background: Over the past years, an increasing trend was noticed for non-B and non- CRF01_AE HIV-1 strains prevalence in Hong Kong.
Objective: In this study, we aimed at using the available HIV-1 pol sequences collected from 1994 to 2013 through our local antiretroviral resistance surveillance program to investigate the molecular epidemiology and evolution of HIV-1 minority subtypes in Hong Kong. We also aimed at investigating their potential association and impact of those transmission risk groups.
Methods: A total of 2,315 HIV-1 partial pol sequences were included. HIV-1 genotypes were determined by REGA Genotyping Tool and phylogenetic analysis with reference sequences. The viral evolutionary rates and time of the most common ancestor (tMRCA) were estimated by Bayesian Markov Chain Monte Carlo (MCMC) interference.
Results: Apart from the two prevalent HIV-1 genotypes in Hong Kong (subtype B,41.6%, CRF01_AE,40.5%), phylogenetic analysis revealed a broad viral diversity including CRF07_BC(5.1%), subtype C(4.5%), CRF02_AG(1.1%), CRF08_BC(0.8%), subtype A1(0.8%), subtype G(0.4%), subtype D(0.4%), CRF06_cpx(0.4%), subtype F(0.1%), CRF12_BF(0·04%) and other recombinants(4.5%). The top five minority subtypes were further analyzed which demonstrated distinct epidemiological and phylogenetic patterns. Over 70% of subtypes A1, C and CRF02_AG infections were circulated among non-Chinese Asians or African community in Hong Kong and were mainly transmitted between heterosexual regular partners. Instead, over 90% of CRF07_BC and CRF08_BC patients were Chinese. An epidemic cluster was identified in CRF07_BC and estimated to expand from 2002 onwards based on skyline plot and molecular clock analysis.
Conclusion: Our results highlighted the emergence of CRF07_BC epidemic in local MSM community, public health interventions targeting the community should be further enhanced to tackle the epidemic.
HIV-1 epidemiology, CRF07_BC, HIV-1 minority subtypes, non-B non-AE transmission, men-who-have-sexwith- men, HIV-1 partial pol gene.
Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Department of Microbiology, Queen Mary Hospital, The University of Hong Kong