Circulation of multiple patterns of unique recombinant forms B/CRF02_AG in France: precursor signs of the emergence of an upcoming CRF B/02

New Subtype B Containing HIV-1 Circulating Recombinant of sub-Saharan Africa Origin in Nigerian Men Who Have Sex With Men

BACKGROUND

HIV-1 circulating recombinant forms (CRF) containing subtype B are uncommon in sub-Saharan Africa. Prevalent infections observed during enrollment of a prospective study of men who have sex with men (MSM) from Lagos, Nigeria, revealed the presence of a family of subtype B and CRF02_AG recombinants. This report describes the HIV-1 genetic diversity within a high-risk, high-prevalence, and previously undersampled cohort of Nigerian MSM.

METHODS

Between 2013 and 2016, 672 MSM were enrolled at the Lagos site of the TRUST/RV368 study. Prevalent HIV-1 infections were initially characterized by pol sequencing and phylogenetic subtyping analysis. Samples demonstrating the presence of subtype B were further characterized by near full-length sequencing, phylogenetic, and Bayesian analyses.

RESULTS

Within this cohort, HIV-1 prevalence was 59%. The major subtype was CRF02_AG (57%), followed by CRF02/B recombinants (15%), subtype G (13%), and smaller amounts of A1, B, and other recombinants. Nine clusters of closely related pol sequences indicate ongoing transmission events within this cohort. Among the CRF02_AG/B, a new CRF was identified and termed CRF95_02B. Shared risk factors and Bayesian phylogenetic inference of the new CRF95_02B and the similarly structured CRF56_cpx indicate a Nigerian or West African origin of CRF56_cpx before its observation in France.

CONCLUSION

With high HIV-1 prevalence, new strains, and multiple transmission networks, this cohort of Nigerian MSM represents a previously hidden reservoir of HIV-1 strains, including the newly identified CRF95_02B and closely related CRF56_cpx. These strains will need to be considered during vaccine selection and development to optimize the design of a globally effective HIV-1 vaccine.

New HIV-1 circulating recombinant form 94: from phylogenetic detection of a large transmission cluster to prevention in the age of geosocial-networking apps in France, 2013 to 2017

BackgroundEnding the HIV pandemic must involve new tools to rapidly identify and control local outbreaks and prevent the emergence of recombinant strains with epidemiological advantages.AimThis observational study aimed to investigate in France a cluster of HIV-1 cases related to a new circulating recombinant form (CRF). The confirmation this CRF's novelty as well as measures to control its spread are presented.MethodsPhylogenetic analyses of HIV sequences routinely generated for drug resistance genotyping before 2018 in French laboratories were employed to detect the transmission chain. The CRF involved was characterised by almost full-length viral sequencing for six cases. Cases' clinical data were reviewed. Where possible, epidemiological information was collected with a questionnaire.ResultsThe transmission cluster comprised 49 cases, mostly diagnosed in 2016-2017 (n = 37). All were infected with a new CRF, CRF94_cpx. The molecular proximity of this CRF to X4 strains and the high median viraemia, exceeding 5.0 log₁₀ copies/mL, at diagnosis, even in chronic infection, raise concerns of enhanced virulence. Overall, 41 cases were diagnosed in the Ile-de-France region and 45 were men who have sex with men. Among 24 cases with available information, 20 reported finding partners through a geosocial networking app. Prevention activities in the area and population affected were undertaken.ConclusionWe advocate the systematic use of routinely generated HIV molecular data by a dedicated reactive network, to improve and accelerate targeted prevention interventions. Geosocial networking apps can play a role in the spread of outbreaks, but could also deliver local targeted preventive alerts.

HIV surveillance combining an assay for identification of very recent infection and phylogenetic analyses on dried spots

BACKGROUND

Transmitted/founder viruses isolated at the early stage of infection are indicators of the variants that are spreading within a population. The French reporting system for new HIV diagnoses is linked to a virological surveillance using dried serum spots.

METHODS

We combined an immunoassay for very recent infection (less than 31 days) to a phylogenetic analysis of transmitted/founder viruses and sociodemographic information to analyze the dynamics of the HIV-1 epidemic during a 3-year period. Bayesian coalescent-based methods were used to explore the temporal and spatial dynamics of the identified clusters.

RESULTS

Of 17 010 dried serum spots collected, 549 very recent infections were identified for which both env sequences and sociodemographic data were available. Non-B transmitted/founder viruses were found in 196 cases (35.7%), belonging to six subtypes and seven circulating recombinant forms. Forty-three dyads/clusters were identified (range 2-11 cases), including 107 individuals (19.5%), mainly MSM. The largest cluster involved MSM infected by a CRF02_AG variant. Reconstruction of viral migrations across time suggests that Paris was the major hub of dissemination.

CONCLUSION

The study shows the feasibility of the surveillance of the HIV epidemic using this methodology. The observation of actively growing spatiotemporal clusters allows identification of specific networks that may be targets for intervention.

Predominance of CRF63_02A1 and multiple patterns of unique recombinant forms of CRF63_A1 among individuals with newly diagnosed HIV-1 infection in Kemerovo Oblast, Russia

Kemerovo Oblast (KO) has had the highest rate of HIV spread in Russia since 2011. The aim of this work was to study the genetic variation of HIV-1 in Kemerovo Oblast. Blood was sampled from a total of 91 HIV-positive antiretroviral-therapy-naïve individuals in 2013 (38) and 2015 (53). HIV-1 subtypes, pol gene drug resistance mutations, and viral tropism were analyzed. In 2013-2015, the prevalence of HIV-1 subtype A decreased in KO from 60.5 to 7.5 %. The samples collected in 2015 from the patients with newly diagnosed HIV demonstrate the current dominance of HIV-1 CRF63_02A1 (71.7 %) and HIV-1 URF63_A1 (20.8 %), their parental viruses being CRF63_02A1 and subtype A. The initially predominant genetic variant, HIV-1 subtype A, was replaced in KO. An unusually high incidence of HIV-1 unique recombinant forms is probably the result of HIV-1 CRF63_02A1 introduction in the group of injection drug users with the initial HIV-1 subtype A infection and the practice of risky behavior that promotes reinfection. HIV-1 CRF63_02A1, which recently emerged in Siberia, and its recombinant forms have an ever-increasing impact on the current HIV epidemic in Russia, making urgent the need for in-depth study of this HIV-1 genetic variant.

Detection of the newly characterized HIV CRF56_cpx in Marseille, southeastern France

OBJECTIVES

We aimed to seek HIV sequences highly similar to CRF56-cpx, a recently described newly circulating B/CRF02/G recombinant HIV, in our local clinical microbiology laboratory sequence database.

METHODS

A recently implemented tool that combines a databank of all HIV nucleotide sequences obtained at our clinical microbiology laboratory with a search tool that uses BLAST was used. A comparative and phylogenetic analysis of HIV protease and reverse transcriptase fragments was performed.

RESULTS

We identified two sequences that were clustered with CRF56-cpx with a bootstrap value of 99% in phylogenetic analyses; these were obtained from two patients diagnosed with HIV in 2009-2011. HIV protease-reverse transcriptase sequences obtained from these two patients shared a mean identity of 98.2±0.2% with previously described CRF56-cpx sequences. Both case patients diagnosed with HIV in our centre were highly sexually active men who have sex with men.

CONCLUSIONS

Our findings highlight the continuous expansion of HIV diversity in France and indicate that real-time surveillance of HIV molecular epidemiology, including the comparison of sequences from laboratory, national, and international databases, might be helpful to identify the emergence, circulation, and transmission of viral strains.

Characteristics of patients recently infected with HIV-1 non-B subtypes in France: a nested study within the mandatory notification system for new HIV diagnoses

The presence of HIV-1 non-B subtypes in Western Europe is commonly attributed to migration of individuals from non-European countries, but the possible role of domestic infections with non-B subtypes is not well investigated. The French mandatory anonymous reporting system for HIV is linked to a virological surveillance using assays for recent infection (<6 months) and serotyping. During the first semester of years 2007 to 2010, any sample corresponding to a non-B recent infection was analyzed by sequencing a 415-bp env region, followed by phylogenetic analysis and search for transmission clusters. Two hundred thirty-three recent HIV-1 infections with non-B variants were identified. They involved 5 subtypes and 7 circulating recombinant forms (CRFs). Ninety-two cases (39.5%) were due to heterosexual transmissions, of which 39 occurred in patients born in France. Eighty-five cases (36.5%) were identified in men having sex with men (MSM). Forty-three recent non-B infections (18.5%) segregated into 14 clusters, MSM being involved in 11 of them. Clustered transmission events included 2 to 7 cases per cluster. The largest cluster involved MSM infected by a CRF02_AG variant. In conclusion, we found that the spread of non-B subtypes in France occurs in individuals of French origin and that MSM are particularly involved in this dynamic.

Characterization of CRF56_cpx, a new circulating B/CRF02/G recombinant form identified in MSM in France

Several B/CRF02_AG Unique Recombinant Forms (URFs) have previously been identified in France. Here we show that one of them (URF5_B/02/G) is emerging in MSM, a high-risk population where HIV incidence and number of superinfections are increasing. We describe this new Circulating Recombinant Form, CRF56_cpx, estimate the time to its most recent common ancestor, investigate its origins and show that it probably shares common ancestors with strains from the East Mediterranean.

Increasing HIV-1 non-B subtype primary infections in patients in France and effect of HIV subtypes on virological and immunological responses to combined antiretroviral therapy

BACKGROUND

To analyze the time trends of the viral subtype distributions according to gender, risk group, and geographical origin of the patients in 1128 primary human immunodeficiency virus type 1 infection (PHI), diagnosed in France (1996-2010). To study whether the viral diversity had an impact on the virological and immunological responses in patients initiating combined antiretroviral therapy (cART) soon after infection.

METHODS

The study population comprised PHI patients enrolled in the ANRS-PRIMO-cohort. Subtypes were determined by phylogenetic analysis of reverse transcriptase gene. Viral suppression (<400 copies/mL and <50 copies/mL) and CD4 T-cell counts increase were assessed for those who initiated cART at PHI diagnosis.

RESULTS

Non-B subtypes (285/1128, 25.3%) were present in all regions of France and all risk groups, and increased in frequency over time. Non-B strains were highly diverse and included 6 subtypes, 10 circulating recombinant forms (CRFs), and several unique recombinant forms (URFs). Virological response in patients infected with a non-B virus was similar to that of patients with a subtype-B virus over the first 2 years of cART. Patients infected with either a CRF02_AG strain or another non-B virus had better immunological responses than those infected with a subtype-B virus.

CONCLUSIONS

Over the last 15 years in France, viral diversity has increased in all risk groups. This is the first large study comparing the responses of patients treated since PHI and showing a similar virological and immunological response to cART between the 2 groups of patients (B and non-B). Our results are encouraging for countries where non-B strains predominate in view of the increasing availability of cART.

Global epidemiology of HIV infection in men who have sex with men

Epidemics of HIV in men who have sex with men (MSM) continue to expand in most countries. We sought to understand the epidemiological drivers of the global epidemic in MSM and why it continues unabated. We did a comprehensive review of available data for HIV prevalence, incidence, risk factors, and the molecular epidemiology of HIV in MSM from 2007 to 2011, and modelled the dynamics of HIV transmission with an agent-based simulation. Our findings show that the high probability of transmission per act through receptive anal intercourse has a central role in explaining the disproportionate disease burden in MSM. HIV can be transmitted through large MSM networks at great speed. Molecular epidemiological data show substantial clustering of HIV infections in MSM networks, and higher rates of dual-variant and multiple-variant HIV infection in MSM than in heterosexual people in the same populations. Prevention strategies that lower biological transmission and acquisition risks, such as approaches based on antiretrovirals, offer promise for controlling the expanding epidemic in MSM, but their potential effectiveness is limited by structural factors that contribute to low health-seeking behaviours in populations of MSM in many parts of the world.

Continuous spread of HIV-1 subtypes D and CRF01_AE in France from 2003 to 2009

Among 61 and 35 patients who were infected in France by viruses of the rare clades D and CRF01_AE, respectively, approximately half of them originated from areas where HIV-1 is endemic, but the data showed that both clades have spread in the French indigenous population, particularly in men having sex with men (MSM).

Most HIV type 1 non-B infections in the Spanish cohort of antiretroviral treatment-naïve HIV-infected patients (CoRIS) are due to recombinant viruses

HIV-1 group M is classified into 9 subtypes, as well as recombinants favored by coinfection and superinfection events with different variants. Although HIV-1 subtype B is predominant in Europe, intersubtype recombinants are increasing in prevalence and complexity. In this study, phylogenetic analyses of pol sequences were performed to detect the HIV-1 circulating and unique recombinant forms (CRFs and URFs, respectively) in a Spanish cohort of antiretroviral treatment-naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS). Bootscanning and other methods were used to define complex recombinants not assigned to any subtype or CRF. A total of 670 available HIV-1 pol sequences from different patients were collected, of which 588 (87.8%) were assigned to HIV-1 subtype B and 82 (12.2%) to HIV-1 non-B variants. Recombinants caused the majority (71.9%) of HIV-1 non-B infections and were found in 8.8% of CoRIS patients. Eleven URFs (accounting for 13.4% of HIV-1 non-B infections), presenting complex mosaic patterns, were detected. Among them, 10 harbored subtype B fragments. Four of the 11 URFs were found in Spanish natives. A cluster of three B/CRF02_AG recombinants was detected. We conclude that complex variants, including unique recombinant forms, are being introduced into Spain through both immigrants and natives. An increase in the frequency of mosaic viruses, reflecting the increasing heterogeneity of the HIV epidemic in our country, is expected.