Dynamics and molecular evolution of HIV-1 strains in Sicily among antiretroviral naïve patients

HIV-1 subtype B is the most frequent strain in Sicily. To date, there is no available data about the genetic diversity of HIV-1 viral strains circulating in Sicily among antiretroviral (ARV) naïve subjects and the role of immigration as potential determinant of evolutionary dynamics of HIV-1 molecular epidemiology.For this purpose, HIV-1 polymerase (pol) sequences obtained from 155 ARV naïve individuals from 2004 to 2009 were phylogenetically analysed.The overall rate of HIV-1 non-B infections was 31.0% (n = 48/155), increasing from 7.8% in 2004–2006 to 40.9% in 2009, and about one-third were identified as unique recombinant forms.CRF02_AG was the prevalent non-B clade (n = 28/48, 58.3%), while subtype C-related strains were responsible for about 30% HIV-1 infections.Non-B viruses strictly associated with heterosexual transmission (85.4%) and were mostly found among immigrants (77.1%). Phylogenetic analysis of non-B sequences found in foreign-born subjects was geographically correlated to the respective country of origin. Moreover, the detection of non-B viral variants in the autochthonous population may support an increasing genetic diversity in Sicily as well as a local circulation of HIV strains also uncommon in our country.In Sicily, HIV-1 epidemic is still mostly attributable to the B subtype. Nevertheless, migration and population movements are progressively introducing novel HIV-1 subtypes causing a continuous increase of HIV-1 molecular dynamic at local level. Molecular surveillance is needed to monitor the genetic evolution of HIV-1 epidemic.     

High genetic diversity of HIV-1 was found in men who have sex with men in Shijiazhuang, China

Men who have sex with men (MSM) have become one of the populations with severely HIV prevalence in China. However, very few genetic studies have been done on HIV-1 spreading in this population. In this study, the genetic characterization of HIV-1 strains prevalent in the MSM in Shijiazhuang, China, was analyzed basing on the HIV-1 full-length gag, pol, and partial env gene. 21 drug-naïve HIV-1 sero-positive patients were enrolled into the study. Full length gag, pol, partial env genes and some near full length genomes were amplified with nest RT-PCR followed by sequencing. Multiple subtypes, including CRF01_AE (52.9%), subtype B (35.3%) and CRF07_BC (11.8%), were found in the population. Phylogenetic analysis showed close relationship between our strains with those from Beijing MSM but not those from paid blood donors of local area. Drug resistance surveillance evaluation showed no transmitted drug resistance (TDR). However, some drug-resistance related polymorphism sites (V181I and V106I) were popularly found in B subtype strains. The findings will contribute to understanding the distribution and evolution of HIV-1 in MSM and also help the behavior change intervention.     

Genetic characterization of HIV-1 strains in Togo reveals a high genetic complexity and genotypic drug-resistance mutations in ARV naive patients

In this study, the genetic diversity of HIV-1 and the presence of genotypic drug-resistance mutations in ARV naive patients in Lomé, the capital city of Togo, was documented for the first time. Between June 2006 and January 2007, 83 plasma samples were collected in Lomé from HIV-1 positive and antiretroviral (ARV) naive individuals. Pol (protease + RT) and env (V3–V5) regions were amplified and sequenced. Phylogenetic and recombination analyses were done to identify the HIV-1 variants. Pol sequences were then inspected to identify presence of drug-resistance mutations based on the WHO list recommended for epidemiological studies. A total of 75 plasma samples were amplified and sequenced in both genomic regions. The phylogenetic analysis showed that CRF02 (48.7% and 51.2%) and G (12.8% and 16.2%) were predominant, followed by A3 (6.4% and 6.2%) and CRF06 (3.8% and 12.5%) in pol and env, respectively. One strain was identified as CRF05 in pol and env. Two divergent subtype A strains in env were undetermined (U) in pol but clustered with a previously described complex recombinant strain, 99GR303. Overall, at least 23/83 (27.7%) strains were recombinant, 19 had a unique recombinant structure in pol, and 4 had discordant subtype/CRF designations between pol and env. The subtypes/CRFs involved in the recombination events corresponded to those already circulating as non-recombinant strains in the country. A total of 8 patients harbored strains with mutations associated to drug resistance: L90M (n = 1), K103N (n = 1), T69N (n = 1), T215S (n = 1), M41L (n = 4).In this study we showed the complexity of the HIV-1 strains circulating in Togo and documented a relative high proportion of ARV naive patients with drug-resistance mutations. The high number of resistant strains observed in Togo needs further attention and additional studies are needed to confirm this trend especially because the national ART program experienced major problems to provide drugs on a regular base.     

凉山彝族自治州HIV/AIDS抗病毒治疗前HIV-1耐药情况及其影响因素分析

目的 了解凉山彝族自治州（凉山州）HIV/AIDS抗病毒治疗前HIV-1耐药情况及其影响因素,为预防HIV-1耐药毒株的传播提供参考依据。方法 分别于2017年1月1日至6月30日、2018年1月1日至6月30日在凉山州开展HIV/AIDS抗病毒治疗前HIV-1耐药的横断面调查。提取获得HIV-1 pol基因区序列,根据2014年WHO耐药监测指南的推荐标准,应用HyPhy 2.2.4和Cytoscape 3.6.1软件进行HIV-1耐药毒株传播网络分析。结果 研究对象464例HIV/AIDS,HIV-1毒株为CRF07_BC亚型的占88.6%（411/464）,总的HIV-1耐药率为9.9%（46/464）,非核苷类反转录酶抑制剂（NNRTI）、核苷类反转录酶抑制剂（NRTI）和蛋白酶抑制剂（PI）耐药率分别为6.7%（31/464）、1.9%（9/464）和0.4%（2/464）;有1组HIV-1新型重组毒株URF_01BC亚型独立成簇并携带相关耐药突变位点;多因素logistic回归分析结果显示,与异性性传播人群相比,注射吸毒人群的HIV-1耐药风险较高（aOR=3.03,95% CI：1.40～6.54）。结论 凉山州HIV/AIDS抗病毒治疗前的HIV-1耐药率较高,且有新型重组毒株URF_01BC亚型携带相关耐药突变位点的成簇传播,建议加强HIV-1耐药毒株传播的预防工作。     

Transmission dynamics and molecular characterization of HIV-1 epidemic among therapeutic failure patients in Santa Catarina state,southern Brazil

The HIV-1 epidemic in southern Brazil is mostly caused by subtype C, which contrasts the dominance of subtype B in the other regions of the country. Santa Catarina (SC), although the smallest state in the southern region, presents one of the highest incidences and mortality rates in Brazil due to AIDS. This work investigated the HIV-1 molecular diversity and phylogenetic transmission networks in SC state by analyzing a database of 3070 sequences of the national genotyping service. HIV-1C proved to be the most frequent subtype, with a significant increase in prevalence over time. HIV-1B was observed to be associated with highly educated men, suggesting a compartmentalization from other subtypes. Such observation was confirmed by the high frequency of HIV-1B circulating in MSM transmission networks. Identified transmission clusters were majority composed by individuals living up to 25 km away and interstate linkages were mainly between southern neighbor states. In general, individuals between 25 and 40 years old and sequences sampled after 2014 were more likely to be in transmission chains, in agreement with the universal treatment protocol launched in 2014. The present study brings new insights about HIV-1 transmission dynamics in southern Brazil.     

Molecular epidemiology of HIV-1 in Iceland: Early introductions,transmission dynamics and recent outbreaks among injection drug users

The molecular epidemiology of HIV-1 in Iceland has not been described so far. Detailed analyses of the dynamics of HIV-1 can give insights for prevention of virus spread. The objective of the current study was to characterize the genetic diversity and transmission dynamics of HIV-1 in Iceland. Partial HIV-1 pol (1020 bp) sequences were generated from 230 Icelandic samples, representing 77% of all HIV-1 infected individuals reported in the country 1985–2012. Maximum likelihood phylogenies were reconstructed for subtype/CRF assignment and determination of transmission clusters. Timing and demographic growth patterns were determined in BEAST. HIV-1 infection in Iceland was dominated by subtype B (63%, n = 145) followed by subtype C (10%, n = 23), CRF01_AE (10%, n = 22), sub-subtype A1 (7%, n = 15) and CRF02_AG (7%, n = 15). Trend analysis showed an increase in non-B subtypes/CRFs in Iceland over the study period (p = 0.003). The highest proportion of phylogenetic clustering was found among injection drug users (IDUs; 89%), followed by heterosexuals (70%) and men who have sex with men (35%). The time to the most recent common ancestor of the oldest subtype B cluster dated back to 1978 (median estimate, 95% highest posterior density interval: 1974–1981) suggesting an early introduction of HIV-1 into Iceland. A previously reported increase in HIV-1 incidence among IDUs 2009–2011 was revealed to be due to two separate outbreaks. Our study showed that a variety of HIV-1 subtypes and CRFs were prevalent in Iceland 1985–2012, with subtype B being the dominant form both in terms of prevalence and domestic spread. The rapid increase of HIV-1 infections among IDUs following a major economic crisis in Iceland raises questions about casual associations between economic factors, drug use and public health.     

Highly divergent subtypes and new recombinant forms prevail in the HIV/AIDS epidemic in Angola: New insights into the origins of the AIDS pandemic

Angola, located in South-Western Africa, has a remarkably low HIV/AIDS prevalence in the adult population (3.7%). It is bordered in the North by the Democratic Republic of Congo (DRC) and Republic of Congo that are at the origin of human HIV-1 infections. It is, therefore, likely that HIV-1 strains circulating in Angola are genetically diverse and representative of the origin of the HIV/AIDS epidemic. The aim of this work was to investigate in detail the genetic diversity and molecular epidemiology of HIV-1 in Angola. Almost 400 sequences were obtained from the gag (p17), pol (PR and RT) and/or env (C2C3) genes of 159 HIV-1 infected patients living in eight provinces of Angola (Benguela, Cabinda, Cuanza Norte, Luanda, Lunda Norte, Malange, Uíge, and Zaire) and their genotype was determined by phylogenetic analyses. Gene regions representing all HIV-1 group M clades were found as well as unclassifiable sequences. In env and pol (RT), two groups of sequences forming distinct sub-clusters within the subtype A radiation were found and may define new A5 and A6 sub-subtypes. Recombinant forms were found in almost half (47.1%) of the patients of which 36.0% were second-generation recombinants. Fifty-eight different patterns of recombination were found. The A subtype, including CRF02_AG, was represented in most recombinant viruses. Epidemiological data suggests that the AIDS epidemic in Angola has probably started as early as 1961, the major cause being the independence war, and spread to Portugal soon thereafter. The extraordinary degree of HIV-1 group M genetic diversity and evolution in Angola may pose unprecedented challenges to diagnostic, treatment and prevention of HIV-1 infection.     

台州市2016-2018年新报告HIV/AIDS抗病毒治疗前HIV-1耐药及亚型流行特征分析

目的 了解台州市新报告HIV/AIDS抗病毒治疗（ART）前HIV-1耐药情况及亚型流行特点。方法 于2016年1月至2018年12月在台州市开展新报告HIV/AIDS在ART前HIV-1耐药的横断面调查,RT-PCR扩增获得HIV-1 pol基因片段并测序,提交序列至斯坦福大学耐药数据库,根据2014年WHO耐药监测指南的推荐标准,确定耐药突变位点以及HIV-1毒株对抗病毒药物的敏感性。结果 2016-2018年台州市新报告HIV/AIDS中成功获得HIV-1 pol基因区序列的研究对象806例,ART前HIV-1耐药率为2.9%（23/806）,其中,非核苷类反转录酶抑制剂（NNRTIs）、核苷类反转录酶抑制剂（NRTIs）和蛋白酶抑制剂（PIs）耐药率分别为1.9%（15/806）、0.6%（5/806）和0.0%。2016-2018年新报告HIV/AIDS在ART前HIV-1耐药率依次分别为1.6%、1.8%和4.8%。NNRTIs和NRTIs耐药突变位点以K103 N（0.7%）和M184I/V（0.5%）为主。HIV-1亚型以CRF01_AE（42.7%,344/806）、CRF07_BC（28.9%,233/806）和CRF08_BC（11.2%,90/806）为主。同性性传播者HIV-1亚型以CRF01_AE（53.3%,136/255）和CRF07_BC（32.2%,82/255）为主;异性性传播者HIV-1亚型以CRF01_AE（37.7%,203/539）、CRF07_BC（27.5%,148/539）和CRF08_BC（16.1%,87/539）为主。结论 2016-2018年台州市新报告HIV/AIDS在ART前HIV-1耐药率处于低流行状态,但存在上升趋势,需加强对HIV-1耐药型毒株的监测工作。     

Molecular typing of the local HIV-1 epidemic in Serbia

Worldwide HIV-1 pandemic is becoming increasingly complex, with growing heterogeneity of subtypes and recombinant viruses. Previous studies have documented HIV-1 subtype B as the predominant one in Serbia, with limited presence and genetic diversity of non B subtypes. In recent years, MSM transmission has become the most frequently reported risk for HIV infection among newly diagnosed patients in Serbia, but very little is known of the network structure and dynamics of viral transmission in this and other risk groups. To gain insight about the HIV-1 subtypes distribution pattern as well as characteristics of HIV-1 transmission clusters in Serbia, we analyzed the genetic diversity of the pol gene segment in 221 HIV-1-infected patients sampled during 2002–2011. Subtype B was found to still be the most prevalent one in Serbia, accounting for over 90% of samples, while greater diversity of other subtypes was found than previously reported, including subtypes G, C, A, F, CRF01 and CRF02. In total, 41.3% of analyzed subtype B sequences were found associated in transmission clusters/network, that are highly related with MSM transmission route.     

Acquisition and transmission of HIV-1 among migrants and Chinese in Guangzhou,China from 2008 to 2012: Phylogenetic analysis of surveillance data

BackgroundPost-migration infection and domestic transmission of HIV-1 between immigrants and local population are critical for the HIV epidemic, but have not been addressed thus far in China.MethodsTransmission clusters were analyzed with two cluster reconstruction methods, HIV-TRACE and Cluster Picker, using 1695 HIV-1 pol sequences obtained from 139 HIV-infected foreigners and 1556 Chinese natives in Guangzhou, China from 2008 to 2012. The geographic origin of the HIV-1 sequences was further determined by PastML while the factors associated with recent HIV-1 transmission were documented by logistic regression analysis.ResultsHIV-1 genotypes that are prevalent in African and East Asian countries were identified in HIV-infected Chinese subjects and vice versa. In addition, more NRTI drug resistance mutations were found in HIV-infected foreigners than in native Chinese (p < 0.001). HIV-1 transmission between HIV-infected foreigners and native Chinese individuals was documented in 12.95% (18/139) of the HIV-infected foreigners. Furthermore, Asian (odds ratio [OR] = 3.45), male (OR = 16.88) and those with known HIV-1 infection routes (OR = 3.23) were more likely associated with recent HIV-1 transmission in China. The Chinese natives linked to recent HIV-1 transmission were more likely to be infected through men who have sex with men (OR = 3.05) or people who inject drugs (OR = 3.05), rather than by heterosexual transmission.ConclusionOur study demonstrates the impact of recent HIV-1 transmission between HIV-infected foreigners and Chinese natives on the HIV-1 epidemic in Guangzhou, China. Moreover, the results highlight the importance of phylogenetic analysis of HIV-1 surveillance data and the need for specific prevention strategies that target the immigrant population.     

浙江省男男性行为人群HIV-1新近感染者的毒株亚型和传播簇研究

目的 了解浙江省MSM中的HIV-1新近感染者的毒株亚型组成和传播特征.方法 233例2011年新报告的MSM感染者经BED捕获酶免试验(BED-CEIA)检测为新近感染,其中107例纳入分子流行病学研究,收集血浆样本提取RNA核酸,用反转录/巢式PCR扩增HIV病毒的pol基因片段,测序后进行生物信息学分析.结果 107例研究对象与当年MSM新近感染者在社会人口学特征上差异无统计学意义.序列获得率为94.4％(101/107),CRF01 AE占比最高(62.4％),其次是CRF07 BC(31.7％),另有3例B亚型,1例CRF55_01B和2例独特重组型.毒株在系统进化树上主要分为CRF01 AE的簇1、簇2和CRF07_BC的簇3,杭州地区的毒株散播于各个进化分支.共发现10个传播簇,80％涉及≥2个的地市,90％与现住址为杭州的病例有关; 共发现有3个样本各存在一个监测性耐药突变,分别为M46I、T215S和G190A,传播性耐药率为2.97％.结论 浙江省MSM的HIV亚型呈现复杂性趋势,但传播性耐药处于低度流行水平;HIV的跨地区传播较为普遍,杭州在地域上可能发挥着核心传播作用,全省已形成混杂交织的复杂网络.     

浙江省2015年HIV分子亚型特征及其传播关系研究

目的 了解浙江省现阶段HIV毒株亚型流行分布特征和分子网络传播关系。方法 采用分层随机抽样方法抽取浙江省2015年4-6月新发现HIV感染者302例进行横断面调查,运用RT-PCR和巢式PCR扩增pol基因成功获得276份序列,结合流行病学调查数据开展测序及系统进化树分析。结果 276例HIV感染者毒株亚型构成：CRF07_BC 122例（44.2%）,CRF01_AE 103例（37.3%）,CRF08_BC 17例（6.1%）,B亚型9例（3.2%）,CRF55_01B 6例（2.2%）,C亚型5例（1.8%）,CRF59_01B 1例（0.4%）,CRF67_01B 1例（0.4%）,A1亚型1例（0.4%）,URFs 11例（4.0%）。CRF07_BC、CRF01_AE毒株亚型在进化树上已形成明显的分簇现象,传播簇主要集中分布在MSM人群（76.5%）。MSM人群的成簇比例高于其他人群,且不同传播途径感染人群存在传播联系。结论 2015年浙江省HIV主要流行毒株以CRF07_BC、CRF01_AE为主,亚型构成有复杂化趋势,应加强对HIV毒株亚型和流行簇的监控和预警,开展分类管理,针对高风险人群和传播链开展有效防控。     

Identification of major routes of HIV transmission throughout Mesoamerica

BackgroundMigration and travel are major drivers of the spread of infectious diseases. Geographic proximity and a common language facilitate travel and migration in Mesoamerica, which in turn could affect the spread of HIV in the region.Methods6092 HIV-1 subtype B partial pol sequences sampled from unique antiretroviral treatment-naïve individuals from Mexico (40.7%), Guatemala (24.4%), Honduras (19%), Panama (8.2%), Nicaragua (5.5%), Belize (1.4%), and El Salvador (0.7%) between 2011 and 2016 were included. Phylogenetic and genetic network analyses were performed to infer putative relationships between HIV sequences. The demographic and geographic associations with clustering were analyzed and viral migration patterns were inferred using the Slatkin-Maddison approach on 100 iterations of random subsets of equal number of sequences per location.ResultsA total of 1685/6088 (27.7%) of sequences linked with at least one other sequence, forming 603 putative transmission clusters (range: 2–89 individuals). Clustering individuals were significantly more likely to be younger (median age 29 vs 33 years, p < 0.01) and men-who-have-sex-with-men (40.4% vs 30.3%, p < 0.01). Of the 603 clusters, 30 (5%) included sequences from multiple countries with commonly observed linkages between Mexican and Honduran sequences. Eight of the 603 clusters included > 10 individuals, including two comprised exclusively of Guatemalans (52 and 89 individuals). Phylogenetic and migration analyses suggested that the Central and Southern regions of Mexico along with Belize were major sources of HIV throughout the region (p < 0.01) with genetic flow southward from Mexico to the other nations of Mesoamerica. We also found evidence of significant viral migration within Mexico.ConclusionInternational clusters were infrequent, suggesting moderate migration between HIV epidemics of the different Mesoamerican countries. Nevertheless, we observed important sources of transnational HIV spread in the region, including Southern and Central Mexico and Belize.     

浙江省义乌市2016年新报告HIV/AIDS的HIV-1亚型和传播簇分析

目的 了解浙江省义乌市HIV亚型分布和传播簇特征，为HIV流行趋势分析和疫情防治提供依据。方法 对该地区2016年新报告HIV/AIDS开展分子流行病学横断面研究，从168例血浆中提取RNA，通过RT-PCR和巢式PCR扩增pol基因并测序。构建系统进化树分析亚型和传播簇，通过CPR 6.0在线软件工具分析耐药突变位点。结果 研究对象年龄（39.1±13.4）岁，男性为主（86.3%，145/168），外省户籍居多（66.7%，112/168），感染途径为同性传播（51.2%，86/168）和异性传播（48.8%，82/168）。HIV序列成功获得率为89.9%（151/168），优势亚型为CRF01_AE 74例（49.0%）和CRF07_BC 64例（42.4%），其他亚型包括CRF08_BC 5例（3.3%），CRF55_01B 3例（2.0%），B、CRF45_cpx、CRF59_01B、CRF85_BC和URF （B/C）各1例。CRF45_cpx和CRF85_BC在浙江省首次发现。共发现26个传播簇（含65个病例），总成簇比例43.0%（65/151），CRF01_AE成簇比例54.1%（40/74），高于CRF07_BC的32.8%（21/64）；各传播簇平均大小为2.5例/簇，CRF01_AE中异性传播的传播簇最大（3.5例/簇）。传播性耐药率为4.6%（7/151），7例检出监测性耐药突变，包括M46L 5例，F77L和Y181C各1例。结论 义乌市HIV亚型复杂多样，多种传播簇并存且特征多样，应继续加强亚型监测，重点对传播簇病例开展专题调查，实施针对性有效干预。     

Differences of cytotoxic T-lymphocyte pressure and divergent evolution of several CRF07_BC clusters circulating in men who have sex with men in China

The HIV-1 CRF07_BC strain is now the major recombinant form in China among the population of men who have sex with men (MSM), and has critically contributed to the HIV-1 epidemic in recent years. The phylodynamic and virological differences among CRF07_BC clusters circulating in MSM, and the factors that could be driving their evolution, remains unclear. Using the HIV-1 CRF07_BC strains obtained from the Los Alamos HIV database, we undertook a large-scale phylogenetic analysis using the maximum likelihood method of partial gag, pol, and env segments to infer their evolutionary relationships. The demographic histories of clusters were determined using the Bayesian Markov chain Monte Carlo (MCMC) method. For four pol clusters we analyzed the non-synonymous (dN) to synonymous (dS) substitution rates and performed site to site analysis to identify positive selection sites and cytotoxic T-lymphocyte (CTL) escape mutation positions. MSM was found to be the predominant risk factor for all four of the CRF07_BC epidemic pol segment clusters with the largest number of infections. Two of those clusters had higher growth in the effective number of infections, and two clusters had slower growth. Analysis of all four clusters showed no significant differences in the mean substitution rates and dN/dS selection pressure ratios. However, a site to site codon analysis found thirteen significant positive selection sites. Ten of these sites are CTL escape mutations. The two clusters with the higher growth in infections had seven and eight pol segment CTL escape mutation sites respectively, while the two with slower growth had only one or two. Our findings demonstrated differences in the CTL escape mutation and divergent evolution of several CRF07_BC clusters circulating among men who have sex with men in China.     

广东省艾滋病患者HIV-1基因亚型分析

目的 了解目前广东省HIV/AIDS患者HIV-1基因型的流行状况.方法 用套式PCR对222例HIV/AIDS患者外周血单核细胞(PBMC)中HIV前病毒DNA膜蛋白env基因C2-V4区及其邻近区域片段进行扩增,并对片段进行序列测定,与国际HIV-1标准毒株序列进行比较,依据同源性确定基因型.结果 222例患者中,...