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New approaches to HIV vaccine development.

Development of a safe and effective vaccine for HIV is a major global priority. However, to date, efforts to design an HIV vaccine with methods used for development of other successful viral vaccines have not succeeded due to HIV diversity, HIV integration into the host genome, and ability of HIV to consistently evade anti-viral immune responses. Recent success in isolation of potent broadly neutralizing antibodies (bnAbs), in discovery of mechanisms of bnAb induction, and in discovery of atypical mechanisms of CD8T cell killing of HIV-infected cells, have opened new avenues for strategies for HIV vaccine design.

AIDS Vaccines

Intestinal microbiome changes in response to amino acid and micronutrient supplementation: secondary analysis of the AMAZE trial.

Microbial dysbiosis has been linked to environmental enteropathy (EE) and alterations in nutrient absorption; however, compositional modifications following exposure to supplementary nutrients are poorly understood. Here, we report the effect of amino acid and micronutrient supplementation on the gut microbiome of adults with EE. In the AMAZE trial, adults with EE were randomized to amino acids (AA) and/or micronutrients (MM) for 16 weeks in a 2 × 2 factorial design against placebo. Endoscopy was performed before and after intervention, during which duodenal aspirates were collected as well as fecal samples. 16S rRNA amplicon sequencing was performed on both these samples, and differences in bacterial community composition before and after interventions were investigated using differential abundance analysis, corrected using false discovery rate, plus alpha and beta diversity measurements. HIV seropositive participants exhibited lower alpha and beta diversity at baseline. AA and/or MM supplementation did not show significant changes in abundance or diversity of genera post-intervention compared to placebo. Micronutrient supplementation resulted in an increase in the pyruvate fermentation to acetone MetaCyc pathways compared to the placebo arm. This study provides insights into the responsiveness of the gut microbiome to micronutrient and amino acid supplementation in adults with EE.

HIV

Brief Report: Beyond Testing: Exploring the Psychosocial Impact of HIV Self-Testing Among Ugandan Gender-Diverse Sex Workers.

BACKGROUND: The psychosocial effect of HIV self-testing (HIVST) on sex workers' self-esteem, depression, alcohol misuse, perceived sex work stigma, and empowerment remains poorly characterized. We hypothesized that HIVST would reduce sex work stigma and improve these psychosocial outcomes by enabling private, autonomous testing and reducing exposure to stigmatizing healthcare encounters. SETTING: Kampala, Uganda. METHODS: We conducted a secondary analysis of the Empower study (NCT03426670), an open-label randomized trial in which 117 cisgender female, transgender female, and cisgender male sex workers were assigned 1:1 to monthly HIVST plus quarterly clinic-based testing, or to quarterly clinic-based testing alone, and followed for 12 months. Self-esteem (Rosenberg Self-Esteem Scale), depressive symptoms (PHQ-2), alcohol misuse (RAPS4), perceived sex work stigma (adapted Female Sex Worker Stigma Scale), and empowerment were assessed quarterly. Mixed-effects regression models, adjusted for baseline values, evaluated intervention effects. RESULTS: Data from 117 participants were analyzed, including 7 early disenrollments. Over 12 months, HIVST participants reported significantly lower perceived sex work stigma than standard of care participants (β = -0.38, P = 0.04; monthly reduction P = 0.003), although the rate of decline did not differ significantly between arms (interaction P = 0.08). Self-esteem and depressive symptoms improved in both arms, with no between-arm differences (interaction P = 0.41 and 0.32). Alcohol misuse and empowerment showed no significant arm differences. CONCLUSION: HIVST may reduce sex work stigma without adverse psychosocial effects, supporting its integration into combination HIV prevention for gender-diverse sex workers in sub-Saharan Africa.

Humans

Pervasive HIV recombination limits the utility of circulating recombinant form nomenclature.

The naming of HIV-1 circulating recombinant forms (CRFs)-descendent viruses from the same intersubtype recombination events, is along with the designation of 'subtypes' and 'groups', routinely used to track HIV-1 diversity. However, we argue that continuing to designate all detected CRFs as distinct entities is biologically unjustified, as many represent recombinants of limited epidemiological significance. Indeed, the mechanistic underpinning of HIV-1 recombination highlights the arbitrary nature of naming these incidental recombinants, the majority of which are rarely detected again. This underlines the need to prioritise taxonomically meaningful clades, with a focus on biological significance such as emergence events associated with significant epidemiological spread, phenotypic properties or transmission advantage.

HIV-1

Genetic Evolution Between HIV-1 Groups M and O: HIV-1/MO Recombinant Forms.

HIV exhibits significant genetic diversity, with genetic recombination being a major evolutionary process. The co-circulation of HIV-1/M and HIV-1/O variants has led to the description of 20 HIV-1/M+O dual infections since 1998. Despite the genetic divergence between these variants, HIV-1/M+O dual infections have resulted in the emergence of HIV-1/MO intergroup recombinant forms, with 20 unique HIV-1/MO recombinant forms (URF_MO) currently described, raising the question of a possible benefit of the recombination and the modalities of their emergence. This review summarized the current knowledge of HIV-1/MO recombinant forms, including their virological and genetic characteristics, phylogenetic analysis, genome profiles, and breakpoints number and location. This study also identified the potential impacts of HIV-1/MO recombination on diagnosis, monitoring, and treatment, as well as the replicative capacity of such recombinants. This review highlighted the greater diversity and complexity of HIV-1/MO recombinants than originally thought, offering new research perspectives on their emergence and virological properties.

HIV-1

A New Type of Nonsuppressible Viremia Produced by HIV-Infected Macrophage.

BACKGROUND: HIV-1 RNA typically declines rapidly after initiation of antiretroviral therapy (ART); often reaching undetectable levels within a few weeks and remaining undetectable by standard assays. However, some patients on ART have persistent nonsuppressible viremia (NSV) that does not respond to treatment optimization or intensification. NSV can emerge at the time of ART initiation (primary NSV) or after being ART-suppressed (secondary NSV). Here, we examine mechanisms producing primary NSV in four people on ART. METHODS: Blood samples were collected from four participants who, despite being adherent to ART, required approximately a year or more to become virologically suppressed. Viral RNA and proviral DNA genomes were sequenced to examine HIV-1 drug resistance, genome intactness and genetic diversity. The ability of HIV-1 Envs to facilitate efficient entry into cells expressing low levels of CD4 (a proxy for macrophage tropism) was assessed. RESULTS: Before ART, the blood contained HIV-1 RNA genomes that were adapted to replication in CD4+ T cells and rapidly decayed after ART initiation. During ART, the blood contained HIV-1 genomes that were drug sensitive, genetically diverse, macrophage-tropic, not evolving and often had defects in vpr. CONCLUSIONS: Our results suggest that in individuals with primary NSV, ART stopped virus replication, but large pools of long-lived, HIV-infected macrophage continued to produce virus. This is mechanistically distinct from secondary NSV produced by CD4+ T cell clones. In addition, defects in vpr independently accumulation in macrophage-tropic lineages found in three participants, suggesting that vpr may impact survival of, or virus production from, HIV-infected macrophage.

Journal Article

Comprehensive Transcriptome Annotation of Thousands of HIV-1 Genomes.

Alternative splicing in HIV-1 has been a central focus of decades of research, uncovering key mechanisms of viral gene regulation, immune evasion, and therapeutic response - yet, no reference resource has existed to support transcriptome-wide analysis, limiting adoption of modern computational methods. We present HIV Atlas (https://ccb.jhu.edu/HIV_Atlas), the first reference-quality annotation of HIV-1 and SIV transcriptional diversity. We manually curated transcriptomes for HIV-1HXB2 and SIVmac239 and developed Vira, an automated annotation-transfer method specifically designed to address unique challenges of viral genome biology, to generate high-quality annotations for 2,077 complete HIV-1 genomes. Using the resources presented in our work, we evaluated conservation of splice sites, revealing near-perfect preservation of major donors and acceptors. Furthermore, using several public datasets, we demonstrate how HIV Atlas enhances methodology, improves the quality and novelty of results, and opens novel avenues for research, supporting more accurate and comprehensive analyses of bulk, single-cell, and spatial RNA-seq in HIV-1 studies.

Journal Article

Kaposi Sarcoma-Associated Herpesvirus Sequencing in People Living With HIV in the Southern United States Reveals Subtype Diversity and Multiple Infections.

Kaposi sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma and lymphoproliferative diseases collectively identified as KSHV-associated diseases (KAD). While KAD incidence has decreased across the United States, regional and population-based variability exists, with higher rates in southern states. To understand the molecular epidemiology of KSHV in this region, samples were collected from people living with HIV (PWH) with or without history of KAD. PWH, mainly men who have sex with men (MSM), were recruited from a large, urban hospital system in Dallas, Texas, in two separate studies. The studies included 220 individuals without KAD and 59 patients with KAD. Whole blood and/or oral fluids were collected and tested by qPCR. KSHV subtypes were determined from 66 of 85 individuals with detectable KSHV loads by a combination of next-generation and targeted Sanger sequencing. All major KSHV subtypes, except D, were observed including subtypes E and F. In each of three individuals, multiple KSHV genome variants were identified. This study importantly highlights KSHV subtype diversity in the southern United States, which is an area with a high KS incidence. Genome diversity and multiple infections merit epidemiological consideration, including for the future development of vaccines.

Humans

Intentions to use different modalities of long-acting HIV PrEP among men who have sex with men and transgender and gender diverse persons in the Netherlands.

Insight into intentions to use long-acting HIV pre-exposure prophylaxis (PrEP) is essential for successful implementation. We assessed intention to use three hypothetical long-acting PrEP modalities (oral, intramuscular and subdermal) among HIV-negative men who have sex with men (MSM) and transgender and gender diverse persons in Amsterdam, recruited through the Amsterdam Cohort Studies (ACS-participants) and social media (survey-participants). Intention was measured per modality using a 7-point Likert scale. We modeled the probability of high intention to use long-acting PrEP using relative risk regression. Of 1258 participants [1231 (97.9%) MSM; 557 ACS and 701 survey; median age 40 years (IQR 32-50)], 76% had ever used oral short-acting PrEP. Intention to use was highest for monthly oral long-acting PrEP [ACS: median 4.5 (IQR 2-6), 38% high intention; survey: median 7 (IQR 6-7), 81% high intention], followed by 2-monthly intramuscular PrEP [ACS: median 3 (IQR 2-5), 19% high intention; survey: median 5 (IQR 3-7), 47% high intention], and implants [ACS: median 2 (IQR 1-4), 9% high intention; survey: median 4 (IQR 2-7), 37% high intention]. PrEP-experienced participants had higher intention to use oral long-acting PrEP and injectables than PrEP-naïve participants. Offering multiple PrEP modalities may improve the acceptability of HIV prevention strategies and increase PrEP uptake and retention in PrEP care.

Humans

Multiomics profiling of plasma reveals lipid-immune dysregulation and exosome remodeling in mpox and mpox-HIV co-infection.

BACKGROUND: Monkeypox virus (MPXV) infects diverse human cell types, and human immunodeficiency virus (HIV) co-infection is common. The immunometabolic consequences of MPXV infection, and how it may be altered by HIV, remain poorly defined. METHODS: We performed quantitative plasma lipidomics and precise metabolomics in a discovery cohort (n = 81) comprising MPXV-monoinfected (MPLWOH), MPXV-HIV-coinfected (MPLWH), and HIV-monoinfected (PLWH) patients and healthy controls, integrating exosome proteomics, cytokine profiling, and transcriptomics of exosome-treated HepG2 and A549 cells for functional interpretation. An independent validation cohort (n = 65) was used to assess cross-cohort reproducibility. FINDINGS: MPXV infection induced broad lipid remodeling, with elevations in phosphatidylserine (PS) and phosphatidylethanolamine (PE) and reductions in phosphatidylcholine (PC), lysophospholipids, cholesteryl ester (CE), and exosomal lecithin-cholesterol acyltransferase (LCAT) and lipoprotein lipase (LPL). These lipid alterations were correlated with tissue injury markers and inflammatory cytokines. The MPLWH group exhibited more severe metabolic disruption, including marked sulfatide (SL) depletion, lower cholesterol and high-density lipoprotein cholesterol (HDL-c), and extensive rewiring of lipid-cytokine associations. SL depletion in MPLWH correlated with abundances of COPI-mediated retrograde trafficking proteins in exosomes. Transcriptomic profiling of exosome-treated cells provided functional validation: MPLWOH exosomes induced lipid metabolism and repair-associated epithelial programs, while MPLWH exosomes drove phospholipid remodeling and acute inflammatory and mucosal barrier-stress responses. CONCLUSIONS: MPXV infection reprograms host lipid metabolism and exosome composition, with HIV co-infection amplifying inflammatory, metabolic, and trafficking disruptions. These convergent multi-omics signatures link systemic lipid dysregulation to exosome-mediated immunomodulation and identify potential targets for host-directed interventions. FUNDING: This study was funded by the Major Project of Guangzhou National Laboratory.

Adult

Autologous neutralizing antibodies increase with early antiretroviral therapy and shape HIV rebound after treatment interruption.

Early initiation of antiretroviral therapy (ART) alters viral rebound kinetics after analytic treatment interruption (ATI) and may play a role in promoting HIV-1 remission. Autologous neutralizing antibodies (aNAbs) represent a key adaptive immune response in people living with HIV-1. We aimed to investigate the role of aNAbs in shaping post-ATI HIV-1 rebound variants. We performed single-genome amplification of HIV-1 env from pre-ART and post-ATI plasma samples of 12 individuals who initiated ART early after infection. aNAb activity was quantified using pseudoviruses derived from the most common plasma variant, and the serum dilution that inhibited 50% of viral infections was determined. aNAb responses matured while participants were on suppressive ART, because on-ART plasma and purified immunoglobulin G (IgG) demonstrated improved neutralizing activity against pre-ART HIV-1 strains when compared with pre-ART plasma or purified IgG. Post-ATI aNAb responses exerted selective pressure on the rebounding viruses, because the post-ATI HIV-1 strains were more resistant to post-ATI plasma neutralization compared with the pre-ART virus. Several pre-ATI features distinguished post-treatment controllers from noncontrollers, including an infecting HIV-1 sequence that was more similar to consensus HIV-1 subtype B, more restricted proviral diversity, and a stronger aNAb response. Post-treatment control was also associated with the evolution of distinct N-glycosylation profiles in the HIV-1 envelope. In summary, aNAb responses appeared to mature after early initiation of ART and applied selective pressure on rebounding viruses. The combination of aNAb activity with select HIV-1 sequence and reservoir features identified individuals with a greater chance of post-treatment control.

Humans

HIV-phyloTSI: subtype-independent estimation of time since HIV-1 infection for cross-sectional measures of population incidence using deep sequence data.

BACKGROUND: Estimating the time since HIV infection (TSI) at population level is essential for tracking changes in the global HIV epidemic. Most methods for determining TSI give a binary classification of infections as recent or non-recent within a window of several months, and cannot assess the cumulative impact of an intervention. RESULTS: We developed a Random Forest Regression model, HIV-phyloTSI, which combines measures of within-host diversity and divergence to generate continuous TSI estimates directly from viral deep-sequencing data, with no need for additional variables. HIV-phyloTSI provides a continuous measure of TSI up to 9 years, with a mean absolute error of less than 12 months overall and less than 5 months for infections with a TSI of up to a year. It performs equally well for all major HIV subtypes based on data from African and European cohorts. CONCLUSIONS: We demonstrate how HIV-phyloTSI can be used for incidence estimates on a population level.

HIV Infections

Evolutionary dynamics of HIV-1 recombinants: analysis of contemporary and historical viral populations in East Africa.

BACKGROUND: Understanding the genetic evolution of HIV-1 Transmitted/Founder (T/F) virus is crucial for developing effective treatment and prevention strategies due to its rapid mutation and recombination rates. METHODS: This study compared the genetic diversity of 24 contemporary T/F viruses collected between 2016 and 2021 in Uganda and Kenya with 29 historical T/F sequences sampled between 2006 and 2011. RESULTS: Subtype analysis based on near-full-length (NFL) HIV-1 T/F genomes revealed that 57.1% (12/21) of contemporary viruses were recombinants, predominantly involving Subtype A1, D, and increasing Subtype C, with 33.3% (7/21) being A1D recombinants (A1 > D) and 19% (4/21) classified as complex recombinants involving three or more subtypes. Historical viruses showed a similar overall proportion (69%) but were mainly A1D mosaics (D > A1) with recombination confined primarily to the envelope region. In contrast, contemporary viruses shifted towards more complex recombinant patterns affecting additional genomic regions, including pol and accessory genes. Phylogenetic analysis demonstrated that contemporary viruses clustered into distinct, well-supported (98% bootstrap) sub-branches, suggesting divergency attributed to an imbalance in their proportions of subtype A1 and D sequences as well as a different content of A1 and D segments in the A1/D mosaic recombinants. CONCLUSIONS: These findings underscore the dynamic and shifting nature of HIV-1 genetic diversity in East Africa, highlighting the need for continuous molecular surveillance and region-specific treatment guidelines.

HIV-1

Emergence of two novel HIV-1 Circulating Recombinant Forms (CRF190_0708 and CRF191_0708): molecular characterization and clinical insights from a five-year study in Yunnan, China.

BACKGROUND: To characterize HIV-1 molecular epidemiology and identify novel circulating recombinant forms (CRFs) among antiretroviral therapy (ART)-naïve heterosexuals in Yunnan, China, and evaluate their clinical impact. METHODS: This study examined 636 HIV-1 pol sequences to analyze genetic diversity, pretreatment drug resistance (PDR), and transmission networks. Near full-length genomes were obtained to identify and characterize novel recombinants, with their evolutionary history inferred by Bayesian analysis. Co-receptor tropism was predicted, and the five-year clinical outcomes (including immune reconstitution and virologic response) of patients infected with the novel CRFs were compared. RESULTS: The most prevalent type identified was CRF08_BC, accounting for 50.16% of cases. The prevalence of drug resistance was 5.97% (38/636), with the K103N mutation being the most common. An analysis of transmission networks revealed that 52.2% (272/521) of clusters were associated with CRF07_BC and CRF08_BC. Two novel second-generation CRFs were identified: CRF190_0708, with an estimated time to the most recent common ancestor (tMRCA) of 1998.9, and CRF191_0708, with a more recent tMRCA ranging from 2009.5 to 2011.6. During the five-year follow-up period, viral rebound was observed in 7 patients in the CRF190_0708 group and in 1 patient in the CRF191_0708 group. Drug-resistance mutations (M184V and K103N) were detected in a subset of rebound cases in the CRF190_0708 group. CONCLUSIONS: This study identifies two novel HIV-1 recombinants, CRF190_0708 and CRF191_0708, highlighting ongoing viral evolution in Yunnan. Preliminary findings suggest possible clinical differences, warranting further investigation. Continued molecular surveillance is needed. TRIAL REGISTRATION: The clinical study was registered at ClinicalTrials.gov under the identifier NCT03852849. The date of registration was March 22, 2019.

Adult

Identification of a novel HIV-1 circulating recombinant form (CRF209_cpx) and its descendant unique recombinant form (URF) CRF209_cpx/B among MSM in Guangdong, southern China.

BACKGROUND: The epidemic of human immunodeficiency virus type 1 (HIV-1) continues to pose a significant global health challenge, with increasing genetic diversity. The co-circulation of multiple subtypes among the local population facilitates the emergence of unique or circulating recombinant forms (URFs or CRFs). In China, the predominant strains include CRF07_BC, CRF01_AE, CRF55_01B, and subtype B. This study characterizes a novel CRF209_cpx and its descendant recombinant CRF209_cpx/B among men who have sex with men (MSM) in Guangdong, southern China. METHODS: Individuals infected with URFs with similar genetic characteristics were recruited during routine surveillance of pretreatment drug resistance. Near full-length genomes (NFLGs) were amplified with two overlapping fragments using a serial dilution nested PCR approach after reverse transcription. We used SimPlot and IQ-TREE softwares to conduct recombination analyses and phylogenetic inferences. Time-scaled maximum clade credibility (MCC) phylogenetic trees were reconstructed using BEAST software to estimate evolutionary origins. Genotypic drug resistance mutations were interpreted via the Stanford HIV Database, and coreceptor usage was predicted using geno2pheno coreceptor 2.5 and the HIVcoPRED tool. RESULTS: Four NFLG sequences were obtained and identified as a novel CRF209_cpx, generated by recombination among CRF01_AE, CRF07_BC and subtype B. Phylogenetic analyses revealed that all the parental segments clustered with lineages prevalent among MSM in China. Bayesian evolutionary analysis estimated that the most recent common ancestor (tMRCA) of CRF209_cpx to have evolved between 2011 and 2013. The fifth strain was identified as a URF recombined from nascent CRF209_cpx and B. No transmitted drug resistance mutation was detected in these five sequences. The four CRF209_cpx sequences primarily utilized the CXCR4 coreceptor, while the URF exhibited R5/X4 dual tropism. CONCLUSIONS: The emergence of the complex CRF209_cpx and novel URF of CRF209_cpx/B highlights the active HIV-1 epidemic within the MSM population in Guangdong, underscoring the necessity for enhanced molecular surveillance and precise public health intervention in this key population.

HIV-1

Emerging techniques of CRISPR/Cas system in antiviral therapy and diagnostics: Applications, limitations, and translational perspectives.

The CRISPR/Cas (clustered regularly interspaced short palindromic repeats) system is a versatile technology for developing antiviral medicines and editing viral genomes in both diagnostics and vaccine synthesis. Emerging insights into class 2 effectors, such as Cas9, Cas12, and Cas13, which target viral DNA and RNA, have revolutionized vaccines against viruses such as HIV, HPV, HBV, and EBV. Innovative diagnostic techniques such as SHERLOCK, DETECTR, and FELUDA have demonstrated system's diversity and accuracy in detecting the virus markers, supporting clinical decision-making, indicating adaptability and precision of CRISPR. This review critically evaluates CRISPR's role in RNA editing, emphasizing its importance for functional genomics and development of recombinant vaccines. Translational challenges are critically discussed, including off-target effects, delivery limitations, and ethical issues, for which unique approaches such as high-fidelity Cas variants, non-viral delivery systems, and bioethical frameworks are evaluated to address these limitations. This review also covers other social implications, such as accessibility and biosecurity risks, associated with CRISPR technologies Collectively, these advances underscore the transformative potential of CRISPR technologies in shaping next-generation antiviral diagnostics and therapeutics.

CRISPR-Cas Systems

Experimental approaches for investigating sirtuin-mediated mitochondrial function, cellular metabolism, and epigenetic regulation.

Cellular pathways for experimental discovery provide a comprehensive overview of sirtuin biology and its critical involvement in HIV-associated neurocognitive disorders (HAND) and related neurodegenerative diseases, highlighting the translational potential of sirtuin-targeted therapeutic strategies. As NAD+-dependent deacetylases and ADP-ribosyl transferases, sirtuins regulate diverse cellular processes, including stem cell maintenance, cellular proliferation, metabolic homeostasis, apoptosis, autophagy, oxidative stress responses, and genomic stability, all of which contribute to neuronal dysfunction and disease progression. This chapter focuses on key mammalian sirtuins, including SIRT1 and SIRT2, which are primarily localized within the nucleus and cytosol; mitochondrial sirtuins SIRT3, SIRT4, and SIRT5; and nuclear/nucleolar sirtuins SIRT6 and SIRT7. Here, a method with a detailed protocol to isolate compartment-specific sirtuin expression and activity was used: subcellular fractionation was performed using a subcellular fractionation kit to obtain cytosolic and nuclear fractions, while mitochondrial isolation was carried out using Tom20 antibody-conjugated magnetic microbeads. These approaches were applied to brain tissues from HIV-positive individuals, as well as to HIV-Tat-treated human microglial (HMC3) cells and astrocytes. This experimental framework enables accurate assessment of compartment-resolved sirtuin regulation in disease-relevant models. Collectively, the chapter highlights the protective roles of sirtuins in mitigating key pathogenic mechanisms underlying HAND and related neurodegenerative diseases. These findings support the emerging concept that sirtuins represent promising pharmacological targets for the development of novel therapeutic interventions in neurodegeneration and HIV-associated brain disorders.

Humans

Rapid pan-microbial metagenomics for pathogen detection and personalised therapy in the intensive care unit: a single-centre prospective observational study.

BACKGROUND: Most clinical metagenomic studies do not provide rapid results, detect pathogens from all microbial kingdoms, or measure clinical impacts. We aimed to evaluate the feasibility, performance, and clinical impacts of a rapid pan-microbial respiratory metagenomic service for patients admitted to intensive care units (ICUs). METHODS: This was a single-centre observational study of a rapid metagenomics service that tests respiratory samples from ICU patients at Guy's and St Thomas' hospitals, London, UK, between Dec 5, 2023, and April 12, 2024. Testing used a previously published pan-microbial metagenomics workflow, which simultaneously detects bacteria, fungi, and DNA and RNA viruses; provides same-day preliminary results after 2 h; and provides final results after 24 h. Patients were included if they were aged 18 years or older, admitted to the ICU, had confirmed respiratory failure requiring supplemental oxygen or advanced airway support, and had at least one of the following: (1) clinical suspicion of lower respiratory tract infection based on clinical, biochemical, or radiological findings, (2) sepsis of unknown origin, and (3) concern from an intensive care physician regarding inflammatory pathology. Patients with a suspected or confirmed containment level three organism were excluded. The outcome was performance characteristics of the metagenomic test compared with routine diagnostic testing, detection of additional pathogens by metagenomics, change in antimicrobial prescribing within 24 h of testing, and initiation of immunomodulation. FINDINGS: We processed 114 samples (1-5 per day) from 74 patients (39 [53%] female and 35 [47%] male). 107 (94%) of 114 samples passed quality control, of which 101 (94%) provided same-day preliminary results. Bacteria were detected in 45 (43%) of 104 tested specimens, fungal organisms in 17 (16%) of 104 tested specimens, and viruses in 28 (34%) of 83 tested specimens. Sensitivity in lower respiratory tract samples after 24 h was 97% (95% CI 87-100) for bacteria, 89% (65-99) for fungi, and 89% (71-98) for viruses, with only one false positive for bacteria. Metagenomics identified 42 pathogens not detected by other tests in 32 (30%) of 107 samples. Antimicrobial therapy was changed after metagenomic results from 30 (28%) of 107 samples: 22 (21%) were de-escalated and eight (7%) were escalated. Metagenomics contributed to the initiation of immunomodulation in 15 (20%) of 74 patients for a range of inflammatory conditions. Pathogens with clinical significance to local infection control or national public health were found in ten (14%) of 74 patients, including three invasive Group A streptococci, two parvovirus B19, and one each of HIV-1, measles virus, Mycobacterium tuberculosis, Neisseria meningitidis, and Mycoplasma pneumoniae. INTERPRETATION: Respiratory metagenomics for ICU patients showed good performance and turnaround time, and diverse clinical and public health benefits. This ability to inform both personalised patient therapy and infectious disease surveillance needs evaluation in multicentre studies. FUNDING: None.

Humans