Update on diversity and distribution of HIV-1 subtypes in Yunnan province

Genetic polymorphisms in the C19orf66 gene influenced HIV-1 infection in a Yunnan population

Background

Due to the deficiencies of vaccines and effective medicine, the human immunodeficiency virus (HIV) infection mechanism should be studied. The C19orf66 gene, one of the interferon-stimulated genes (ISGs), expresses broad-spectra anti-viral activity, including inhibiting HIV replication.

Methods

In this study, we collect 421 HIV-1 infected patients and 448 controls to genotype three SNPs in the C19orf66 gene. Then, the association between SNPs and biochemical indices/ HIV-1 subtypes are analyzed.

Results

Genotypes CC and CT of rs12611087 show statistically lower and higher frequencies in HIV-1 infected patients than in controls, respectively. Alleles C and T of rs12611087 play protective and risk roles in Yunnan HIV population, respectively. Biochemical indices analysis shows that HIV-1 infected persons carried genotype TT of rs77076061 express significantly lower CD3+/CD45+ ratio level and higher IBIL level. The epidemic subtypes of HIV-1 patients in this study are CRF 07_BC and CRF 08_BC. Moreover, subtype CRF 08_BC tends to infect persons with genotype CC of rs12611087.

Conclusion

The genetic polymorphisms of the C19orf66 gene are firstly studied and reported to associate with HIV-1 infection and biochemical indices of patients in Yunnan. Furthermore, subtype CRF 08_BC infection could be influenced by genotypes of SNP in the C19orf66 gene.

Prevalence of Different Genotypes of HIV-1 in Injection Drug Users in China: A Systematic Review and Meta-Analysis

BACKGROUND

Since 1981, an increasing trend in HIV has been observed for transmission via injection drug users (IDUs), sexual transmission and mother-to-child transmission. The IDUs are blamed for early increases in HIV-positive cases in China.

OBJECTIVE

HIV genotypes of IDUs were comprehensively analysed to trace the source and relationships of the AIDS epidemic in China.

METHODS

Relevant databases written in English and Chinese were searched. Overall, 7,149 publications were identified in six databases. After screening 7,104 articles according to the inclusion and exclusion criteria, 45 studies consisting of 2,765 cases were finally identified. A meta-analysis was conducted using R MATLAB software, RevMan and SPSS. Subgroup analyses focused on time frame, region, and location of different genotypes of IDUs in China.

RESULTS

There were five dominant HIV-1 genotypes among the 2,765 IDU cases. The proportions of CRF07_BC, CRF01_AE, CRF08_BC, subtype B/B', and subtype C were 45.18% (95% CI: 33.55-57.08%), 16.00% (95% CI: 9.39-23.82%), 13.43% (95% CI: 7.32-20.84%), 3.58% (95% CI: 1.52-6.24%), and 0.90% (95% CI: 0.04-2.43%), respectively. HIV genotypes transmitted among IDUs in China are primarily CRF07-BC, followed by CRF01-AE and CRF08-BC. Across the different time frames and regions, CRF07_BC was the most prevalent HIV-1 genotype among IDUs, while CRF08_BC was the most prevalent genotype in the southwest region.

CONCLUSION

Our study reveals that CRF07-BC was the dominant prevalent strain among IDUs from 1991 to 2015 in China, while CRF08-BC was the dominant prevalent strain among IDUs in southwestern China. This systematic review and meta-analysis shows evidence of the comprehensive prevalence of different genotypes, data and characteristics of HIV among IDUs in China.

Molecular Characterization of HIV-1 Minority Subtypes in Hong Kong: A Recent Epidemic of CRF07_BC among the Men who have Sex with Men Population

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.

High prevalence of HIV-1 transmitted drug resistance among therapy-naïve Burmese entering travelers at Dehong ports in Yunnan, China

BACKGROUND

The overall success of Human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy (ART) was heavily challenged upon the occurrence of drug resistance. Dehong Prefecture witnessed not only the first report of HIV-1 infection but also the experimental adoption of antiviral treatment in China. The transmission and epidemic of HIV-1 in Dehong is impacted by cross-border activities. The characteristics of HIV-1 drug resistance among therapy-naïve Burmese entering travelers in Yunnan and their speculated origin are still not clarified.

METHODS

Two hundred ninety-eight HIV-1 infected Burmese entering travelers at Dehong ports were recruited between 2003 and 2012. The partial HIV-1 pol gene fragments were amplified and sequenced for the analysis of drug-resistance mutations (DRMs). Phylogenetic analysis on gag-pol gene was conducted to elucidate phylogenetic and evolutionary characteristics of these drug resistant strains.

RESULTS

It was figured out that the occurrence ratio of HIV-1 drug resistance among HIV-1 infected entering travelers from Myanmar was up to 12.8%. The resistant mutations covered several types, including one type of PI mutations (L33F), six types of NRTI mutations and seven types of NNRTI. Close genetic relationship was observed in the phylogenetic analysis on gag-pol gene among the drug resistant strains respectively from Dehong, other Yunnan areas, neighboring provinces (Guangxi) and neighboring countries (Thailand and Myanmar).

CONCLUSIONS

The findings in this study revealed that HIV drug resistant locus is spreading from the population who is receiving drug-resistance treatment to the new infectors, which indicates the urgency of surveillance work on drug resistance among the migrant population with high risks of HIV infection.

The changing HIV-1 genetic characteristics and transmitted drug resistance among recently infected population in Yunnan, China

Multiple human immunodeficiency virus (HIV)-1 genotypes in China were first discovered in Yunnan Province before disseminating throughout the country. As the HIV-1 epidemic continues to expand in Yunnan, genetic characteristics and transmitted drug resistance (TDR) should be further investigated among the recently infected population. Among 2828 HIV-positive samples newly reported in the first quarter of 2014, 347 were identified as recent infections with BED-captured enzyme immunoassay (CEIA). Of them, 291 were successfully genotyped and identified as circulating recombinant form (CRF)08_BC (47.4%), unique recombinant forms (URFs) (18.2%), CRF01_AE (15.8%), CRF07_BC (14.4%), subtype C (2.7%), CRF55_01B (0.7%), subtype B (0.3%) and CRF64_BC (0.3%). CRF08_BC and CRF01_AE were the predominant genotypes among heterosexual and homosexual infections, respectively. CRF08_BC, URFs, CRF01_AE and CRF07_BC expanded with higher prevalence in central and eastern Yunnan. The recent common ancestor of CRF01_AE, CRF07_BC and CRF08_BC dated back to 1983.1, 1992.1 and 1989.5, respectively. The effective population sizes (EPS) for CRF01_AE and CRF07_BC increased exponentially during 1991-1999 and 1994-1999, respectively. The EPS for CRF08_BC underwent two exponential growth phases in 1994-1998 and 2001-2002. Lastly, TDR-associated mutations were identified in 1.8% of individuals. These findings not only enhance our understanding of HIV-1 evolution in Yunnan but also have implications for vaccine design and patient management strategies.

Genetic Characterization of a Unique Recombinant Strain Identified in Yunnan with Genome Comprising B and C

Since the first identification of HIV-1 outbreak in Dehong, Yunnan province has been the epidemic center of HIV in China. Owing to the special geographic location and the frequent population mobility, Yunnan province contained complex HIV subtype distribution. Many new circulating recombinant forms (CRFs) and unique recombinant forms (URFs) have been found in recent years. In this study, a unique HIV-1 recombinant strain genome (YN10134) was characterized from an HIV-positive female in Yunnan, China. This virus genome had a complex intersubtype recombinant structure with eight breakpoints, composed of subtypes B and C. Although the sequence had a similar breakpoint with CRF07_BC in the start position in Env, the phylogenetic analysis showed that the segment was not originated from CRF07_BC. The identification of the URF indicated the severity of the HIV epidemic in Yunnan province and the urgent need for epidemiological surveillance of the new recombination.

Phylogenetic characteristics of HIV-1 among travelers entering China from Myanmar: A retrospective study

Due to the open policy of the Chinese government, a large number of Burmese individuals enter China at land ports in Yunnan province for travel or business. However, the situation of HIV-1 infection and its phylogenetic characteristics among these travelers remains unclear, which is a potential threat to public health. From January 2003 to December 2012, a total of 1,961 travelers were detected to be positive for HIV-1 infection at land ports between Myanmar and Yunnan province, China. From 1153 (58.8%) Burmese of them, we randomly collected 489 serum samples for HIV-1 subtype/recombinant analysis. Based on successfully obtained 223 gag-RT sequences, 187 of them were genotyped as 2 subtypes and 3 CRFs. CRF01_AE was showed to be the most prevalent genotype (54.3%), followed by subtypes C (13.5%) and B (10.8%). Notably, CRF07_BC (1.3%) and CRF08_BC (4.0%) were mainly distributed in travelers from Shan state and Kachin (91.7%, 11/12), but was not found in travelers from the capital city of Yangon (0/16). Additionally, there were 36 samples (16.1%) were preliminary determined as unique recombinant forms (URFs). The higher HIV-1 infection among entering travelers from Myanmar and its diverse and complex genotypes distribution suggest this bridge population may facilitate the transmission of HIV-1. It is necessary to have the strict monitoring on this population for prevention of HIV-1 cross-border transmission.

HIV Epidemic in Asia: Implications for HIV Vaccine and Other Prevention Trials

An overall decrease of HIV prevalence is now observed in several key Asian countries due to effective prevention programs. The decrease in HIV prevalence and incidence may further improve with the scale-up of combination prevention interventions. The implementation of future prevention trials then faces important challenges. The opportunity to identify heterosexual populations at high risk such as female sex workers may rapidly wane. With unabating HIV epidemics among men who have sex with men (MSM) and transgender (TG) populations, an effective vaccine would likely be the only option to turn the epidemic. It is more likely that efficacy trials will occur among MSM and TG because their higher HIV incidence permits smaller and less costly trials. The constantly evolving patterns of HIV-1 diversity in the region suggest close monitoring of the molecular HIV epidemic in potential target populations for HIV vaccine efficacy trials. CRF01_AE remains predominant in southeast Asian countries and MSM populations in China. This relatively steady pattern is conducive to regional efficacy trials, and as efficacy warrants, to regional licensure. While vaccines inducing nonneutralizing antibodies have promise against HIV acquisition, vaccines designed to induce broadly neutralizing antibodies and cell-mediated immune responses of greater breadth and depth in the mucosal compartments should be considered for testing in MSM and TG. The rationale and design of efficacy trials of combination prevention modalities such as HIV vaccine and preexposure prophylaxis (PrEP) remain hypothetical, require high adherence to PrEP, are more costly, and present new regulatory challenges. The prioritization of prevention interventions should be driven by the HIV epidemic and decided by the country-specific health and regulatory authorities. Modeling the impact and cost-benefit may help this decision process.

The sexually driven epidemic in youths in China's southwestern border region was caused by dynamic emerging multiple recombinant HIV-1 strains

Dehong prefecture, Yunnan province on China’s southwestern border was the gateway of the country’s AIDS epidemic. Studies on HIV-1 molecular epidemiology will provide key information on virus transmission dynamics and help to inform HIV prevention strategies. HIV-1 infected youths (age 16–25 years) diagnosed in the continuous 3 months in 2009 to 2012 were enrolled. By means of phylogenetic and statistical analyses, It was showed that two thirds (133/205) of youths in Dehong, of which 74.1% were infected sexually, were infected by uncharacterized recombinant HIV-1 strains. Among them about 59.4% (79/131) were unique recombinant forms (URFs) and 40.6% (54/131) formed 11 transmission clusters, termed potential circulating recombinant forms (pCRFs). The emergence of recombinants was statistically significant related with people of low education, residents outside the capital city of Dehong and being Myanmar residents. It was the first report with ongoing HIV-1 recombinant strains in a sexually driven epidemic area in China. Great efforts should be put on reducing multiple risk exposures behavior in local young people, containing the spread of pCRFs to other regions, and preventing the URFs from evolving into future CRFs. Collaborative prevention across border is needed to better control the local AIDS epidemic.

Parallel enzyme-linked immunosorbent assay screening for human immunodeficiency virus among blood donors in five Chinese blood centres: a retrospective analysis

AIMS

To evaluate the strategy of parallel screening with different enzyme-linked immunosorbent assays (ELISA) among Chinese blood donors.

BACKGROUND

Parallel screening with ELISA has been the main strategy to detect human immunodeficiency virus (HIV) in blood donations in China for more than a decade. The performance of the strategy should be analysed.

METHODS

A total of 821,927 donations collected from five Chinese blood centres in 2008-2010 were tested using two third-generation ELISAs by different manufacturers licenced and confirmed by the Western blot (WB) in this study. The confirmatory positive predictive values (PPV), false positive rates (FPR), false negative rates (FNR) and potential risks for transfusion resulting from single or sequential ELISA screening were evaluated.

RESULTS

A total of 5318 (0·647%) of donations screened HIV reactive and were discarded. WB confirmatory results on 1668 available samples suggested that PPVs for dual ELISA, one round ELISA reactive and grey zone samples were 75·1, 0·7 and 0·5%, respectively. Eight out of 1124 one round ELISA reactive and 1 out of 195 grey zone samples were WB confirmed positive. All but one ELISA assay displayed comparable PPVs but variable FPRs and FNRs that differed by blood centre.

CONCLUSIONS

In the absence of nucleic acid testing (NAT), parallel ELISA screening prevented a substantial number of HIV infected donations from entering the Chinese blood supply. However, the loss of false positive donors should be re-evaluated especially given the frequently reported blood supply shortage in China.

An effective tool for identifying HIV-1 subtypes B, C, CRF01_AE, their recombinant forms, and dual infections in Southeast Asia by the multi-region subtype specific PCR (MSSP) assay

The RV144 Thai vaccine trial has been the only vaccine study to show efficacy in preventing HIV infection. Ongoing molecular surveillance of HIV-1 in Southeast Asia is vital for vaccine development and evaluation. In this study a novel tool, the multi-region subtype specific PCR (MSSP) assay, that was able to identify subtypes B, C, CRF01_AE for Thailand, other Southeast Asian countries, India and China is described. The MSSP assay is based on a nested PCR strategy and amplifies eight short regions distributed along the HIV-1 genome using subtype-specific primers. A panel of 41 clinical DNA samples obtained primarily from opiate users in northern Thailand was used to test the assay performance. The MSSP assay provided 73-100% sensitivity and 100% specificity for the three subtypes in each genome region. The assay was then field-tested on 337 sera from HIV infected northern Thai drug users collected between 1999 and 2002. Subtype distribution was CRF01_AE 77.4% (n=261), subtype B 3.3% (n=11), CRF01_AE/B recombinant 12.2% (n=41), CRF01_AE/C recombinant 0.6% (n=2), and non-typeable 6.5% (n=22). The MSSP assay is a simple, cost-effective, and accurate genotyping tool for laboratory settings with limited resources and is sensitive enough to capture the recombinant genomes and dual infections.

Evolving molecular epidemiological profile of human immunodeficiency virus 1 in the southwest border of China

Background

We have previously reported in Xishuangbanna (Banna) Dai Autonomous Prefecture, a well-developed tourist destination in the southwest border of China, that HIV-1 transmitted dominantly through heterosexual contact with less divergent genotypes and few drug resistant mutations [1]. Due to the rapid increase of newly diagnosed HIV-1 cases per year in Banna in recent years, it’s important to evaluate the evolution of HIV-1 molecular epidemiology for the better understanding of ongoing HIV-1 outbreak in this region.

Methodology/Principal Findings

By sequencing of HIV-1 pol genes and phylogenetic analysis, we conducted a molecular epidemiologic study in 352 HIV-1-seropositive highly active antiretroviral treatment (HAART)-naïve individuals newly diagnosed at the Banna Center for Disease Control and Prevention between 2009 and 2011. Of 283 samples (84.1% taken from heterosexually acquired adults, 10.6% from needle-sharing drug users, 2.8% from men who have sex with men, 0.4% from children born from HIV-1-infected mothers, and 2.1% remained unknown) with successful sequencing for pol gene, we identified 108 (38.2%) HIV-1 subtype CRF08_BC, 101 (35.7%) CRF01_AE, 49 (17.3%) CRF07_BC, 5 (1.8%) C/CRF57_BC, 3 (1.1%) B’, 1 (0.4%) B/CRF51_01B, and 16 (5.7%) unique recombinants forms. Among these infected individuals, 104 (36.7%) cases showed drug resistant or resistance-relevant mutations, and 4 of them conferring high-level resistance to 3TC/FTC, EFV/NVP or NFV. Phylogenetic analysis revealed 21 clusters (2–7 sequences) with only 21.2% (60/283) sequences involved.

Conclusion/Significance

In contrast to our previous findings, CRF08_BC, replaced CRF01_AE, became the dominant genotype of HIV-1 in Banna prefecture. The viral strains with drug resistance mutations were detected frequently in newly diagnosed HIV-1-infected individuals in this region.

An HIV Vaccine for South-East Asia-Opportunities and Challenges

Recent advances in HIV vaccine development along with a better understanding of the immune correlates of risk have emerged from the RV144 efficacy trial conducted in Thailand. Epidemiological data suggest that CRF01_AE is still predominant in South-East Asia and is spreading in China with a growing number of circulating recombinant forms due to increasing human contact, particularly in large urban centers, tourist locations and in sites of common infrastructure. A vaccine countering CRF01_AE is a priority for the region. An Asia HIV vaccine against expanding B/E or BCE recombinant forms should be actively pursued. A major challenge that remains is the conduct of efficacy trials in heterosexual populations in this region. Men who have sex with men represent the main target population for future efficacy trials in Asia. Coupling HIV vaccines with other prevention modalities in efficacy trials might also be envisaged. These new avenues will only be made possible through the conduct of large-scale efficacy trials, interdisciplinary teams, international collaborations, and strong political and community commitments.