Molecular transmission network analysis of newly diagnosed HIV-1 infections in Nanjing from 2019 to 2021.

OBJECTIVE: The objective of this study was to conduct a comprehensive analysis of the molecular transmission networks and transmitted drug resistance (TDR) patterns among individuals newly diagnosed with HIV-1 in Nanjing. METHODS: Plasma samples were collected from newly diagnosed HIV patients in Nanjing between 2019 and 2021. The HIV pol gene was amplified, and the resulting sequences were utilized for determining TDR, identifying viral subtypes, and constructing molecular transmission network. Logistic regression analyses were employed to investigate the epidemiological characteristics associated with molecular transmission clusters. RESULTS: A total of 1161 HIV pol sequences were successfully extracted from newly diagnosed individuals, each accompanied by reliable epidemiologic information. The analysis revealed the presence of multiple HIV-1 subtypes, with CRF 07_BC (40.57%) and CRF01_AE (38.42%) being the most prevalent. Additionally, six other subtypes and unique recombinant forms (URFs) were identified. The prevalence of TDR among the newly diagnosed cases was 7.84% during the study period. Employing a genetic distance threshold of 1.50%, the construction of the molecular transmission network resulted in the identification of 137 clusters, encompassing 613 nodes, which accounted for approximately 52.80% of the cases. Multivariate analysis indicated that individuals within these clusters were more likely to be aged ≥ 60, unemployed, baseline CD4 cell count ≥ 200 cells/mm3, and infected with the CRF119_0107 (P < 0.05). Furthermore, the analysis of larger clusters revealed that individuals aged ≥ 60, peasants, those without TDR, and individuals infected with the CRF119_0107 were more likely to be part of these clusters. CONCLUSIONS: This study revealed the high risk of local HIV transmission and high TDR prevalence in Nanjing, especially the rapid spread of CRF119_0107. It is crucial to implement targeted interventions for the molecular transmission clusters identified in this study to effectively control the HIV epidemic.

Epidemic characteristics of local HIV-2 transmission across Hunan province, China.

OBJECTIVE: To elucidate the epidemiological features of HIV-2 in Hunan Province, China, utilizing sequence analysis. METHODS: Thirteen individuals diagnosed with HIV-2 infection in Hunan Province, China, from 2017 to 2023 were included in this study. Amplification of HIV-2 env and pol regions was conducted, followed by Sanger sequencing. Phylogenetic and molecular transmission network analyses were performed to delineate molecular features and transmission dynamics. RESULTS: All 14 individuals contracted HIV-2 through heterosexual intercourse, comprising 7 males and 7 females, with a median age of 58 years. Among them, three couples (HN001 and HN013, HN010 and HN011, HN008 and HN009) were identified, along with commercial sexual activity engagement reported for subject HN004. Notably, subjects HN001, HN003, HN008, and HN010 engaged in commercial sexual activities at the same location as subject HN004. Phylogenetic analysis of the pol gene revealed close proximity of sequences from all subjects to reference sequences from Gambia (Sub-type A). Employing a genetic distance threshold of 1.5 %, eight out of the 14 subjects formed a molecular transmission network, with HN002 and HN004 identified as central nodes. CONCLUSION: From 2017 to 2023, all HIV-2-infected individuals in Hunan Province, China, acquired the virus through identifiable routes, indicating transmission of similar HIV-2 strains among them.

Drug resistance and influencing factors in HIV-1-infected individuals under antiretroviral therapy in Guangxi, China.

OBJECTIVES: To assess the profiles and determinants of drug resistance in HIV-1-infected individuals undergoing ART in Guangxi. METHODS: Samples and data were collected from HIV-1-infected individuals experiencing virological failure post-ART from 14 cities in Guangxi. Sequencing of the HIV-1 pol gene was conducted, followed by analysis for drug resistance mutations using the Stanford University HIV Drug Resistance Database. Logistic regression was employed to identify potential risk factors associated with both HIV drug resistance and mortality. RESULTS: A total of 8963 individuals with pol sequences were included in this study. The overall prevalence of HIV-1 drug resistance (HIVDR) was 42.43% (3808/8963), showing a decrease from 59.62% to 41.40% from 2016 to 2023. Factors such as being aged ≥50 years, male, Han nationality, lower education levels, occupations including workers, peasants and children, AIDS, pre-treatment CD4 T cell counts <200 cells/mm3, infection with CRF01_AE and CRF55_01B subtypes, and ART regimen lamivudine/zidovudine/nevirapine were associated with higher susceptibility to HIVDR. The common mutations were M184V (17.38%) and K103N (22.14%). Additionally, the prevalence of M184V, S68G, M41L and G190A were different between the Han and Zhuang populations. Factors including age, gender, ethnicity, education level, occupation, infectious route, clinical stage, viral load, subtype, ART regimen and HIVDR showed significant associations with mortality. CONCLUSIONS: The factors contributing to drug resistance in the HIV-1 ART individuals in Guangxi appear to be notably intricate. Continuous reinforcement of drug resistance surveillance is imperative, accompanied by the optimization of ART regimens to mitigate virological failures effectively.

HIV-1 drug resistance and genetic diversity in people with HIV-1 in Cape Verde.

OBJECTIVES: To characterize the genetic diversity and drug resistance profiles of people with HIV-1 failing ART in Cape Verde (CV). DESIGN: Cross-sectional study conducted between January 2019 and December 2021 in 24 health centres on the islands of Santiago and São Vicente. METHODS: The HIV-1 pol gene was sequenced in individuals with a detectable viral load. HIV-1 genetic diversity was determined by phylogenetic analysis. Drug resistance mutation patterns and resistance phenotypes were estimated using the Stanford algorithm. RESULTS: Viral load was detected in 73 of 252 (29%) enrolled participants and sequencing data were produced for 58 (79%) participants. CRF02 AG strains predominated (46.5%), followed by subtype G (22.4%). Most patients (80%) had mutations conferring resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) (67%), nucleoside reverse transcriptase inhibitors (55%), integrase inhibitors (10%) and/or protease inhibitors (7%) used in Cape Verde, a significant increase compared with a study conducted in 2010-2011. The most common mutations were M184V/I (43%), K103N/S (36%) and G190A/S (19%). NNRTI resistance was associated with younger age and exposure to two or more drug regimens. CONCLUSION: The HIV-1 epidemic in Cape Verde is mainly driven by CRF02_AG and subtype G. Resistance to NNRTIs and/or NRTIs is highly prevalent and resistance to LPV/r and DTG is emerging. Our results support the use of DTG-based first-line ART and protease inhibitor-based regimens for patients with virological failure, but emerging resistance to LPV/r and DTG is a concern. Continued monitoring of drug resistance is essential to ensure adequate healthcare for PWH in Cape Verde.

Molecular Epidemiology of HIV-1 Subtypes and Primary Antiretroviral Resistance Profiles in Northern Cyprus: First Data Series.

The distribution of human immunodeficiency virus-1 (HIV-1) subtypes indicates difference from region to region and in risk groups acquiring the disease worldwide. Although subtype C is more in terms of total cases, subtype B is dominant in certain regions, especially in western and central Europe. Molecular epidemiological studies are essential for the control, effective treatment, and understanding in transmission routes of HIV-1 infection. This study aims to determine the molecular epidemiology and antiretroviral drug resistance profiles of HIV-1 in northern Cyprus. The study involved 71 naive HIV-positive patients diagnosed in northern Cyprus between 2016 and 2022. HIV-1 subtypes and circulating recombinant forms (CRFs) were identified by phylogenetic analysis (neighbor-joining method) of pol gene sequences. Drug resistance mutations were analyzed using the World Health Organization (WHO) lists of mutations for surveillance. The Stanford University HIVdb program was used to interpret drug resistance mutations. In our study, 40 of 71 samples were successfully sequenced. Subtype B of HIV-1 was dominant with a rate of 52.5%, followed by CRF02_AG (20%) and G (7.5%) subtypes. The rate of subtype B (71.4%) in northern Cyprus was significantly higher than in the other country of origin (p = .028). Antiretroviral drug resistance was found in 15% of the sequenced serum samples. Nucleoside/nucleotide reverse transcriptase inhibitor (NRTI), non-nucleoside nucleotide reverse transcriptase inhibitor (NNRTI), and protease inhibitor (PI) resistance rates were 10% (4/40), 7.5% (3/40), and 2.5% (1/40), respectively. According to the results, it is noteworthy that the dominant subtype circulating in northern Cyprus is the B subtype, and CRFs were detected at a higher rate than expected.

Drug Resistance Mutations in a Population Before Antiretroviral Therapy Initiation in Northern South Africa.

South Africa introduced the "diagnose and treat" universal HIV treatment program in September 2016. This program enables all identified HIV-positive patients to immediately start first-line antiretroviral therapy (ART). However, the presence of drug-resistant (DR) viruses in the drug-naive population complicates the choice of ART. We used next-generation sequencing (NGS) to determine the prevalence and diversity of HIV DR mutations in patients entering HIV treatment programs in northern South Africa. RNA was isolated from plasma of drug-naive HIV-1-infected patients. Using reverse transcriptase polymerase chain reaction, the HIV-1-pol gene comprising the complete protease (PR) and the first 900 bp of reverse transcriptase (RT) was amplified and sequenced on an Illumina MiniSeq platform. Consensus sequences were derived at >20% threshold and at >5% threshold using Geneious PRIME® software version 2020.1.2. HIV-1 surveillance drug resistance mutations (SDRM) were inferred using Calibrated Population Resistance tool in HIV Drug Resistance Database. Viral subtypes were determined using REGA and RIP genotyping tools. The HIV PR/RT region was successfully sequenced from 241 patients. From these, 23 (9.5%) had at least one SDRM detected at >20% threshold, with a prevalence of 9.5% (n = 18), 3% (n = 7), and 0.4% (n = 1) for non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI), and protease inhibitors (PI), respectively. The number of patients with SDRM increased to 31 (12.9%) when minority variants were accounted for at >5% threshold. The most frequent SDRMs based on drug class were; K103N (7.9%-NNRTI), K65R (2.5%-NRTI), and D30N (0.8%-PI). Four cases of dual NRTI/NNRTI mutations were identified. All consensus sequences were subtype C, except three, which were C/A1, C/F1, and C/G recombinants. NGS analysis confirms that individuals entering HIV treatment programs in northern South Africa, habor moderate levels of SDRM, including cases of dual-class drug resistance. Further SDRM studies may be required to better understand resistance in the drug-naive population in the era of "diagnose and treat" in Limpopo Province, South Africa.

Drug resistance pattern among ART-naive clients attending an HIV testing and counseling center in Dhaka, Bangladesh.

In Bangladesh, antiretroviral therapy (ART) is provided without screening drug resistance-associated mutations (DRM) among people living with HIV, while DRM might emerge and transmit to the newly infected individual. The present study was aimed to identify DRM among ART-naive clients from an HIV testing and counseling (HTC) center in the initial stages of ART programs. Randomly selected (n = 64) archived plasma samples were used for the pol gene amplification and sequencing by sanger technology. Recovered sequences (n = 10) were genotyped using HIV genotyping tools of NCBI and analyzed using the Stanford University HIV drug resistance database (hivdb.stanford.edu). Various genotypes with a number of DRM were identified in HTC clients, who belonged to different risk groups based on behavioral data. The drug resistance algorithm showed that all samples were fully resistant to tipranavir/ritonavir drugs except for one intermediate resistance. Despite the small sample size, our understanding from this study warrants an ART policy with a DRM monitoring system for the country.

Molecular transmission networks and pre-treatment drug resistance among individuals with acute HIV-1 infection in Baoding, China.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) genetic diversity and pre-treatment drug resistance (PDR) are major barriers to successful antiretroviral therapy (ART). In China, sexual intercourse is the most frequent route of HIV-1 transmission. However, few studies have analyzed PDR and transmission networks in detail among individuals in China with acute HIV-1 infection and their sexual contacts. METHODS: A cross-sectional study was conducted in Baoding City, Hebei Province, China from 2019-2020. CD4 T cell counts and viral loads were assessed and a HIV-1 genotypic PDR assay was developed in-house. Transmission networks were visualized using Cytoscape with a threshold genetic distance of 0.015 among HIV-1 subtypes. RESULTS: From 139 newly diagnosed and drug-naïve individuals with HIV-1, 132 pol gene sequences were obtained and revealed eight HIV-1 subtypes. Circulating recombinant form (CRF)01_AE was the most frequent subtype (53.0%, 70/132) followed by CRF07_BC (26.5%, 35/132), B (13.6%, 18/132), unique recombinant forms (2.3%, 3/132), CRF55_01B (1.5%, 2/132), CRF103_01B (1.5%, 2/132), CRF65_cpx (0.8%, 1/132), and C (0.8%, 1/132). A total of 47 pol gene sequences were used to generate 10 molecular transmission networks. The overall prevalence of PDR was 7.6% and that of PDR to non-nucleotide reverse transcriptase inhibitors was 6.1%. Of three transmission networks for PDR, two were closely associated with Beijing and Tianjin, while another was restricted to sequences determined in this study. CONCLUSIONS: These results demonstrate that during acute HIV-1 infection, PDR is transmitted in dynamic networks. This suggests that early detection, diagnosis, surveillance, and treatment are critical to effectively control HIV-1 spread.

Prevalence and factors associated with HIV-1 drug resistance mutations in treatment-experienced patients in Nairobi, Kenya: A cross-sectional study.

ABSTRACT: An estimated 1.5 million Kenyans are HIV-seropositive, with 1.1 million on antiretroviral therapy (ART), with the majority of them unaware of their drug resistance status. In this study, we assessed the prevalence of drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors, and the variables associated with drug resistance in patients failing treatment in Nairobi, Kenya.This cross-sectional study utilized 128 HIV-positive plasma samples obtained from patients enrolled for routine viral monitoring in Nairobi clinics between 2015 and 2017. The primary outcome was human immunodeficiency virus type 1 (HIV-1) drug resistance mutation counts determined by Sanger sequencing of the polymerase (pol) gene followed by interpretation using Stanford's HIV Drug Resistance Database. Poisson regression was used to determine the effects of sex, viral load, age, HIV-subtype, treatment duration, and ART-regimen on the primary outcome.HIV-1 drug resistance mutations were found in 82.3% of the subjects, with 15.3% of subjects having triple-class ART resistance and 45.2% having dual-class resistance. NRTI primary mutations M184 V/I and K65R/E/N were found in 28.8% and 8.9% of subjects respectively, while NNRTI primary mutations K103N/S, G190A, and Y181C were found in 21.0%, 14.6%, and 10.9% of subjects. We found statistically significant evidence (P = .013) that the association between treatment duration and drug resistance mutations differed by sex. An increase of one natural-log transformed viral load unit was associated with 11% increase in drug resistance mutation counts (incidence rate ratio [IRR] 1.11; 95% CI 1.06-1.16; P < .001) after adjusting for age, HIV-1 subtype, and the sex-treatment duration interaction. Subjects who had been on treatment for 31 to 60 months had 63% higher resistance mutation counts (IRR 1.63; 95% CI 1.12-2.43; P = .013) compared to the reference group (<30 months). Similarly, patients on ART for 61 to 90 months were associated with 133% higher mutation counts than the reference group (IRR 2.33; 95% CI 1.59-3.49; P < .001). HIV-1 subtype, age, or ART-regimen were not associated with resistance mutation counts.Drug resistance mutations were found in alarmingly high numbers, and they were associated with viral load and treatment time. This finding emphasizes the importance of targeted resistance monitoring as a tool for addressing the problem.

Genetic characteristics of HIV-1 CRF06_cpx and CRF56_cpx strains isolated in Guangzhou, China.

Strains of the HIV-1 circulating recombinant forms (CRFs) 06_cpx and 56_cpx were identified for the first time in Guangzhou, China. The nearly full-length genome (NFLG) sequence was amplified, and the PCR products were sequenced by the Sanger method. The CRF06_cpx and CRF56_cpx strains were identified using the Basic Local Alignment Search Tool (BLAST) and confirmed by neighbour-joining (NJ) phylogenetic analysis. Additionally, these strains were found to contain transmitted drug resistance mutations that have little effect on first-line efavirenz (EFV)-based treatment. Genetic analysis of the detailed sequence data will provide more information on the HIV-1 epidemic in China.

Genetic Characterization of a New HIV-1 Sub-Subtype A in Cabo Verde, Denominated A8.

Previous molecular characterization of Human immunodeficiency virus (HIV-1) samples from Cabo Verde pointed out a vast HIV-1 pol diversity, with several subtypes and recombinant forms, being 5.2% classified as AU-pol. Thus, the aim of the present study was to improve the characterization of these AU sequences. The genomic DNA of seven HIV-1 AU pol-infected individuals were submitted to four overlapping nested-PCR fragments aiming to compose the full-length HIV-1 genome. The final classification was based on phylogenetic trees that were generated using the maximum likelihood and bootscan analysis. The genetic distances were calculated using Mega 7.0 software. Complete genome amplification was possible for two samples, and partial genomes were obtained for the other five. These two samples grouped together with a high support value, in a separate branch from the other sub-subtypes A and CRF26_A5U. No recombination was verified at bootscan, leading to the classification of a new sub-subtype A. The intragroup genetic distance from the new sub-subtype A at a complete genome was 5.2%, and the intergroup genetic varied from 8.1% to 19.0% in the analyzed fragments. Our study describes a new HIV-1 sub-subtype A and highlights the importance of continued molecular surveillance studies, mainly in countries with high HIV molecular diversity.

Let It Go: HIV-1 cis-Acting Repressive Sequences.

After human immunodeficiency virus type 1 (HIV-1) was identified in the early 1980s, intensive work began to understand the molecular basis of HIV-1 gene expression. Subgenomic HIV-1 RNA regions, spread throughout the viral genome, were described to have a negative impact on the nuclear export of some viral transcripts. Those studies revealed an intrinsic RNA code as a new form of nuclear export regulation. Since such regulatory regions were later also identified in other viruses, as well as in cellular genes, it can be assumed that, during evolution, viruses took advantage of them to achieve more sophisticated replication mechanisms. Here, we review HIV-1 cis-acting repressive sequences that have been identified, and we discuss their possible underlying mechanisms and importance. Additionally, we show how current bioinformatic tools might allow more predictive approaches to identify and investigate them.

Phylogenetic Clustering among Asylum Seekers with New HIV-1 Diagnoses in Montreal, QC, Canada.

Migrants are at an increased risk of HIV acquisition. We aimed to use phylogenetics to characterize transmission clusters among newly-diagnosed asylum seekers and to understand the role of networks in local HIV transmission. Retrospective chart reviews of asylum seekers linked to HIV care between 1 June 2017 and 31 December 2018 at the McGill University Health Centre and the Jewish General Hospital in Montreal were performed. HIV-1 partial pol sequences were analyzed among study participants and individuals in the provincial genotyping database. Trees were reconstructed using MEGA10 neighbor-joining analysis. Clustering of linked viral sequences was based on a strong bootstrap support (>97%) and a short genetic distance (<0.01). Overall, 10,645 provincial sequences and 105 asylum seekers were included. A total of 13/105 participant sequences (12%; n = 7 males) formed part of eight clusters. Four clusters (two to three people) included only study participants (n = 9) and four clusters (two to three people) included four study participants clustered with six individuals from the provincial genotyping database. Six (75%) clusters were HIV subtype B. We identified the presence of HIV-1 phylogenetic clusters among asylum seekers and at a population-level. Our findings highlight the complementary role of cohort data and population-level genotypic surveillance to better characterize transmission clusters in Quebec.

Using molecular transmission networks to understand the epidemic characteristics of HIV-1 CRF08_BC across China.

HIV-1 CRF08_BC has become a major epidemic in heterosexuals and intravenous drug users (IDUs) in southern China. In order to evaluate the trends of its epidemic and facilitate targeted HIV prevention, we constructed the genetic transmission networks based on its pol sequences, derived from the National HIV Molecular Epidemiology Survey. Through retrospective network analysis, to study the epidemiological and demographic correlations with the transmission network. Of the 1,829 study subjects, 639 (34.9%) were clustered in 151 transmission networks. Factors associated with increased clustering include IDUs, heterosexual men, young adults and people with lower education (P < 0.05 for all). The IDUs, MSM, young adult and person with low education had more potential transmission links as well (P < 0.05 for all). The most crossover links were found between heterosexual women and IDUs, with 30.9% heterosexual women linked to IDUs. The crossover links heterosexual women were mainly those with middle age and single (P < 0.001). This study indicated that the HIV-1 CRF08_BC epidemic was still on going in China with more than one third of the infected people clustered in the transmission networks. Meanwhile, the study could help identify the active CRF08_BC spreader in the local community and greatly facilitate précising AIDS prevention with targeted intervention.

HIV drug resistance and HIV transmission risk factors among newly diagnosed individuals in Southwest China.

BACKGROUND: The widespread use of antiretroviral therapy (ART) has resulted in the development of transmitted drug resistance (TDR), which reduces ART efficacy. We explored TDR prevalence and its associated risk factors in newly diagnosed individuals in Guangxi. METHODS: We enrolled 1324 participants who were newly diagnosed with HIV-1 and had not received ART at voluntary counselling and testing centres (VCT) in Guangxi, China, who had not received ART. Phylogenetic relationship, transmission cluster, and genotypic drug resistance analyses were performed using HIV-1 pol sequences. We analysed the association of demographic and virological factors with TDR. RESULTS: In total, 1151 sequences were sequenced successfully, of which 83 (7.21%) showed evidence of TDR. Multivariate logistic regression analysis revealed that there was significant difference between the prevalence of TDR and unmarried status (adjusted odds ratio (aOR) = 2.41, 95% CI: 1.23-4.71), and CRF08_BC subtype (aOR = 2.03, 95% CI: 1.13-3.64). Most cases of TDR were related to resistance to non-nucleoside reverse transcriptase inhibitors (4.87%) and V179E was the most common mutation detected. We identified a total of 119 HIV transmission clusters (n = 585, 50.8%), of which 18 (15.1%) clusters showed evidence of TDR (36, 41.86%). Three clusters were identified that included drug-resistant individuals having a transmission relationship with each other. The following parameters were associated with TDR transmission risk: Unmarried status, educational level of junior high school or below, and CRF08_BC subtype may be a risk of the transmission of TDR. CONCLUSIONS: Our findings indicated that moderate TDR prevalence and highlighted the importance of continuous TDR monitoring and designing of strategies for TDR mitigation.

HIV-1 Gag-Pol Sequences from Ugandan Early Infections Reveal Sequence Variants Associated with Elevated Replication Capacity.

The ability to efficiently establish a new infection is a critical property for human immunodeficiency virus type 1 (HIV-1). Although the envelope protein of the virus plays an essential role in receptor binding and internalization of the infecting virus, the structural proteins, the polymerase and the assembly of new virions may also play a role in establishing and spreading viral infection in a new host. We examined Ugandan viruses from newly infected patients and focused on the contribution of the Gag-Pol genes to replication capacity. A panel of Gag-Pol sequences generated using single genome amplification from incident HIV-1 infections were cloned into a common HIV-1 NL4.3 pol/env backbone and the influence of Gag-Pol changes on replication capacity was monitored. Using a novel protein domain approach, we then documented diversity in the functional protein domains across the Gag-Pol region and identified differences in the Gag-p6 domain that were frequently associated with higher in vitro replication.

Patterns and risk of HIV-1 transmission network among men who have sex with men in Guangxi, China.

The prevalence of HIV-1 in Guangxi is very high, and the rate of HIV-1 infection among men who have sex with men (MSM) has been increasing. Therefore, it is necessary to explore the patterns and risk factors of HIV transmission in Guangxi. For this purpose, individuals diagnosed with HIV-1 during 2013-2018 in Guangxi were recruited. Phylogenetic relationship, transmission clusters, and genotypic drug resistance analyses were performed based on HIV-1 pol sequences. Related factors were analysed to assess for their association with HIV-1 transmission. CRF07_BC (50.4%) and CRF01_AE (33.4%) were found to be the predominant subtypes. The analysed 1633 sequences (50.15%, Guangxi; 49.85%, other provinces) were segregated into 80 clusters (size per cluster, 2-704). We found that 75.3% of the individuals were in three clusters (size Ëƒ 100), and 73.8% were high-risk spreaders (links ≥ 4). Infection time, marital status, and subtype were significantly associated with HIV-1 transmission. Additionally, 80.2% of recent infections were linked to long-term infections, and 46.2% were linked to other provinces. A low level of transmitted drug resistance was detected (4.8%). Our findings indicated superclusters and high-risk HIV-1 spreaders among the MSM in Guangxi. Effective strategies blocking the route of transmission should be developed.

Molecular Transmission Dynamics of Primary HIV Infections in Lazio Region, Years 2013-2020.

Molecular investigation of primary HIV infections (PHI) is crucial to describe current dynamics of HIV transmission. Aim of the study was to investigate HIV transmission clusters (TC) in PHI referred during the years 2013-2020 to the National Institute for Infectious Diseases in Rome (INMI), that is the Lazio regional AIDS reference centre, and factors possibly associated with inclusion in TC. These were identified by phylogenetic analysis, based on population sequencing of pol; a more in depth analysis was performed on TC of B subtype, using ultra-deep sequencing (UDS) of env. Of 270 patients diagnosed with PHI during the study period, 229 were enrolled (median follow-up 168 (IQR 96-232) weeks). Median age: 39 (IQR 32-48) years; 94.8% males, 86.5% Italians, 83.4% MSM, 56.8% carrying HIV-1 subtype B. Of them, 92.6% started early treatment within a median of 4 (IQR 2-7) days after diagnosis; median time to sustained suppression was 20 (IQR 8-32) weeks. Twenty TC (median size 3, range 2-9 individuals), including 68 patients, were identified. A diagnosis prior to 2015 was the unique factor associated with inclusion in a TC. Added value of UDS was the identification of shared quasispecies components in transmission pairs within TC.

Microdrop Human Immunodeficiency Virus Sequencing for Incidence and Drug Resistance Surveillance.

BACKGROUND: Precise and cost-efficient human immunodeficiency virus (HIV) incidence and drug resistance surveillances are in high demand for the advancement of the 90-90-90 "treatment for all" target. METHODS: We developed microdrop HIV sequencing for the HIV incidence and drug resistance assay (HIDA), a single-blood-draw surveillance tool for incidence and drug resistance mutation (DRM) detection. We amplified full-length HIV envelope and pol gene sequences within microdroplets, and this compartmental amplification with long-read high-throughput sequencing enabled us to recover multiple unique sequences. RESULTS: We achieved greater precision in determining the stage of infection than current incidence assays, with a 1.2% false recency rate (proportion of misclassified chronic infections) and a 262-day mean duration of recent infection (average time span of recent infection classification) from 83 recently infected and 81 chronically infected individuals. Microdrop HIV sequencing demonstrated an increased capacity to detect minority variants and linked DRMs. By screening all 93 World Health Organization surveillance DRMs, we detected 6 pretreatment drug resistance mutations with 2.6%-13.2% prevalence and cross-linked mutations. CONCLUSIONS: HIDA with microdrop HIV sequencing may promote global HIV real-time surveillance by serving as a precise and high-throughput cross-sectional survey tool that can be generalized for surveillance of other pathogens.

Phylogenetic clustering networks among heterosexual migrants with new HIV diagnoses post-migration in Australia.

BACKGROUND: It is estimated that approximately half of new HIV diagnoses among heterosexual migrants in Victoria, Australia, were acquired post-migration. We investigated the characteristics of phylogenetic clusters in notified cases of HIV among heterosexual migrants. METHODS: Partial HIV pol sequences obtained from routine clinical genotype tests were linked to Victorian HIV notifications with the following exposures listed on the notification form: heterosexual sexual contact, injecting drug use, bisexual sexual contact, male-to male sexual contact or heterosexual sexual contact in combination with injecting drug use, unknown exposure. Those with heterosexual sexual contact as the only exposure were the focus of this study, with the other exposures included to better understand transmission networks. Additional reference sequences were extracted from the Los Alamos database. Maximum likelihood methods were used to infer the phylogeny and the robustness of the resulting tree was assessed using bootstrap analysis. Phylogenetic clusters were defined on the basis of bootstrap and genetic distance. RESULTS: HIV pol sequences were available for 332 of 445 HIV notifications attributed to only heterosexual sexual contact in Victoria from 2005-2014. Forty-three phylogenetic clusters containing at least one heterosexual migrant were detected, 30 (70%) of which were pairs. The characteristics of these phylogenetic clusters varied considerably by cluster size. Pairs were more likely to be composed of people living with HIV from a single country of birth (p = 0.032). Larger clusters (n≥3) were more likely to contain people born in Australian/New Zealand (p = 0.002), migrants from more than one country of birth (p = 0.013) and viral subtype-B, the most common subtype in Australia (p = 0.006). Pairs were significantly more likely to contain females (p = 0.037) and less likely to include HIV diagnoses with male-to-male sexual contact reported as a possible exposure (p<0.001) compared to larger clusters (n≥3). CONCLUSION: Migrants appear to be at elevated risk of HIV acquisition, in part due to intimate relationships between migrants from the same country of origin, and in part due to risks associated with the broader Australian HIV epidemic. However, there was no evidence of large transmission clusters driven by heterosexual transmission between migrants. A multipronged approach to prevention of HIV among migrants is warranted.