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Incorporating Epidemiological Data into the Genomic Analysis of Partially Sampled Infectious Disease Outbreaks.

Pathogen genomic data are increasingly being used to investigate transmission dynamics in infectious disease outbreaks. Combining genomic data with epidemiological data should substantially increase our understanding of outbreaks, but this is highly challenging when the outbreak under study is only partially sampled, so that both genomic and epidemiological data are missing for intermediate links in the transmission chains. Here, we present a new dynamic programming algorithm to perform this task efficiently. We implement this methodology into the well-established TransPhylo framework to reconstruct partially sampled outbreaks using a combination of genomic and epidemiological data. We use simulated datasets to show that including epidemiological data can improve the accuracy of the inferred transmission links compared with inference based on genomic data only. This also allows us to estimate parameters specific to the epidemiological data (such as transmission rates between particular groups), which would otherwise not be possible. We then apply these methods to two real-world examples. First, we use genomic data from an outbreak of tuberculosis in Argentina, for which data was also available on the HIV status of sampled individuals, in order to investigate the role of HIV coinfection in the spread of this tuberculosis outbreak. Second, we use genomic and geographical data from the 2003 epidemic of avian influenza H7N7 in the Netherlands to reconstruct its spatial epidemiology. In both cases, we show that incorporating epidemiological data into the genomic analysis allows us to investigate the role of epidemiological properties in the spread of infectious diseases.

Humans

ScITree: Scalable Bayesian inference of transmission tree from epidemiological and genomic data.

Phylodynamic models capture joint epidemiological-evolutionary dynamics during an outbreak, providing a powerful tool to enhance understanding and management of disease transmission. Existing phylodynamic approaches, however, mostly rely on various non-mechanistic or semi-mechanistic approximations of the underlying epidemiological-evolutionary process. Previous work by Lau and colleagues has shown that full Bayesian mechanistic models, without relying on these approximations, can enable highly accurate joint inference of the epidemiological-evolutionary dynamics including the unobserved transmission tree. However, the Lau method faces major computational bottlenecks. As the volume of genomic data collected during outbreaks continues to grow, it is crucial to develop scalable yet accurate phylodynamic methods. Here we propose a new Bayesian phylodynamic model, overcoming the major scalability issue in the previous method and enabling a readily deployable, yet accurate, phylodynamic modeling framework. Specifically, we develop a scalable spatio-temporal phylodynamic framework for inferring the transmission tree (ScITree) and other key epidemiological parameters considering the infinite sites assumption in modeling mutation on the sequence level, in contrast to the Lau method in which mutation was modeled explicitly on the nucleotide level. Our approach features full Bayesian implementation utilizing an exact likelihood to mechanistically integrate epidemiological and evolutionary processes. We develop a computationally-efficient data-augmentation Markov Chain Monte Carlo algorithm, inferring key model parameters and unobserved dynamics including the transmission tree. We assess performance of our method using multiple simulated outbreak datasets. Our results indicate that our method can achieve high inference accuracy, comparable to the performance of the Lau method. Additionally, our method scales significantly more efficiently for large outbreaks, with computing time increasing linearly with outbreak size, compared to the exponential scaling of the Lau method. We also demonstrate our method's utility by applying our validated modeling framework to a dataset describing a foot-and-mouth disease outbreak in the UK. Our results show that our method is able to generate estimates of the transmission dynamics consistent with those from the prior method, further demonstrating the robustness of our new approach. In summary, our method provides a computationally-efficient, highly scalable, accurate modeling framework for inferring the joint spatio-temporal dynamics of epidemiological and evolutionary processes, facilitating timely and effective outbreak responses in space and time. Our method is implemented in our R package ScITree.

Bayes Theorem

New Delhi metallo-β-lactamase-producing Acinetobacter baumannii in the USA from October, 2013, to March, 2022: a retrospective molecular epidemiological analysis.

BACKGROUND: Most US carbapenem-resistant Acinetobacter baumannii (CRAB) isolates harbour carbapenem-hydrolysing class D β-lactamases. Other carbapenemases, such as New Delhi metallo-β-lactamase (NDM), are uncommon but emerging. We describe the epidemiology of NDM-producing CRAB reported to the US Centers for Disease Control and Prevention (CDC). METHODS: We defined cases as A baumannii with blaNDM confirmed by molecular testing and isolated from any specimen source from a patient in the USA between Oct 1, 2013, and March 31, 2022, and passively reported to the CDC from regional, state, local public health, and CDC laboratories. Epidemiologically linked cases had epidemiological linkage (eg, overlapping health-care facility stay) with one or more other cases. We assessed case relatedness through analysis of whole-genome sequence data using traditional multilocus sequence typing (MLST; Oxford scheme [sequence typeOX]) and core genome MLST. To understand the potential origins of NDM-CRAB in the USA, we compared sequences of cases to US CRAB without NDM and to NDM-CRAB from non-US locations. FINDINGS: We identified 327 NDM-CRAB cases from 264 patients in 21 US states. Among patients with available epidemiological information, 192 (90%) of 214 had epidemiological linkage to at least one additional case and 13 (7%) of 193 were hospitalised outside the USA 12 months or less before index specimen collection. Five regionally distinct sequence type clusters were identified among the 264 case patients; three (sequence type OX218, sequence type OX281, and sequence type OX1697) were closely related to international NDM-CRAB isolates. INTERPRETATION: We identified regionally distinct NDM-CRAB strains, suggesting localised transmission in the USA. Some NDM-CRAB strains in the USA are closely related to strains identified outside the USA, suggesting that spread followed importation. FUNDING: None.

Acinetobacter baumannii

Genomic Epidemiology of the Main SARS-CoV-2 Variants Circulating in Italy During the Omicron Era.

Since early 2022 the Omicron variant has rapidly spread worldwide, becoming the dominant variant to date. The study aimed to investigate the clinical and epidemiological characteristics of COVID-19 patients and reconstruct the genomic epidemiology of main SARS-CoV-2 Omicron sublineages in Italy in 2022. A total of 8970 SARS-CoV-2 samples were studied, and phylogenetic analyses were focused on BA.1, BA.2, and BA.5 subvariants. More than half of subjects received three doses of vaccine and experienced a reinfection. A significant larger proportion of unvaccinated subjects presented reinfection compared with vaccinated. Clusters presented a tMRCA between September-November 2021 (BA.1), November 2021-January 2022 (BA.2), and October 2021-May 2022 (BA.5). Re values showed the highest level between September-October, January-February 2022, and May 2022 for BA.1, BA.2 and BA.5, respectively. Limited number of studied variant sequences are included in clusters. The spread rate of the studied variant exceeded its evolutionary rate. No single sublineage had sufficient time to differentiate into large clusters, but only into small and fragmented groups sharing the same recent ancestor. These analyses dissect the epidemiological dynamics of Omicron sublineages in Italy over a period of great epidemiological changes in the COVID-19 epidemic.

Humans

Genomic epidemiology of clade Ia monkeypox viruses circulating in the Central African Republic in 2022-24: a retrospective cross-sectional study.

BACKGROUND: The spread of monkeypox virus (Orthopoxvirus monkeypox) clade Ib from the Democratic Republic of the Congo to neighbouring countries has raised global concerns, leading to WHO declaring mpox a public health emergency on Aug 14, 2024. We applied genomic epidemiology to investigate the causes of recurrent mpox outbreaks in the Central African Republic. We aimed to determine whether frequent zoonotic spillovers or increased human-to-human transmissions are driving mpox epidemiology. METHODS: We performed a retrospective cross-sectional study of monkeypox virus genomic sequences among PCR-confirmed mpox cases detected in the Central African Republic between Feb 17, 2022, and Sept 17, 2024. We used hybridisation capture coupled to high throughput sequencing to analyse 46 samples from mpox outbreaks that occurred in eight of the 20 prefectures (14 of 35 health districts). Near-complete genomes were used for phylogenomic analyses. FINDINGS: Between Jan 10, 2022, and Sept 15, 2024, 89 mpox cases were confirmed, including 53 cases in the first 9 months of 2024. We generated 41 near-complete genomes from this period, including 33 from 2024. All new and already published monkeypox virus genomes from the Central African Republic belonged to clade Ia. These genomes spanned the phylogenetic diversity of clade Ia viruses, and most likely represented several dozen independent transmission events to humans. The monkeypox virus phylogenetic diversity was geographically structured within the country. Plausibly linked cases often showed indistinguishable genomes. Conversely, we detected identical genomes in cases that epidemiological information would suggest were independent outbreaks. Finally, we found that three distinct viruses caused cases in the capital city of Bangui in July, 2024, with all three detected on the same day (July 24, 2024). We did not detect substantial enrichment of APOBEC3 editing, suggesting limited human-to-human transmission. INTERPRETATION: The data indicate that mpox epidemiology in the Central African Republic is primarily driven by short-lived outbreaks resulting from many independent zoonotic spillover events, particularly in rural areas. Although evidence remains limited, in Bangui additional factors such as movement of people and importation of bushmeat from other regions might be introducing the virus into urban settings. Similar spillover patterns have been observed in the Democratic Republic of the Congo. The poorly understood nature of monkeypox virus reservoirs in both countries is a regional concern, as frequent spillovers increase the risk of outbreaks leading to sustained human transmission. Beyond strengthening surveillance and developing countermeasures, it is important to better understand the reservoirs and focus on reducing transmission opportunities to prevent further outbreaks. FUNDING: Pasteur Institute of Bangui, Africa CDC, AFROSCREEN, WHO, the Helmholtz Institute for One Health, and the Deutsche Forschungsgemeinschaft.

Humans

Epidemiological and phylogenetic analysis of anthrax in Kazakhstan in 2024.

BACKGROUND: Anthrax remains an important zoonotic disease in Kazakhstan due to the persistence of environmental reservoirs and long-standing endemic foci. Despite ongoing surveillance, the epidemiological characteristics and genetic diversity of circulating Bacillus anthracis strains in the country remain incompletely understood. METHODS: A retrospective epidemiological and phylogenetic investigation of anthrax outbreaks reported in Kazakhstan during 2024 was conducted. Epidemiological data were collected for all laboratory-confirmed human cases and associated outbreak foci. Confirmation of infection was performed by PCR, and B. anthracis isolates were obtained from clinical, environmental and animal-associated samples. Whole-genome sequencing and core-genome single nucleotide polymorphism (cgSNP) analysis were used to characterize the genetic relationships among isolates and to determine their phylogenetic placement. RESULTS: Nine anthrax outbreaks were identified across four regions of Kazakhstan (Almaty, Zhambyl, Atyrau, and West Kazakhstan), resulting in 20 confirmed human cases. All patients were male, with the highest proportion occurring among individuals aged 36-55 years (45%). The mean patient age was 43.9 years (range: 16-64 years). Most infections were associated with slaughtering infected livestock (65%), followed by handling contaminated meat (15%). PCR confirmed infection in all 20 human cases. Culture yielded 17 human-derived B. anthracis isolates from 14 patients and 17 environmental/animal-derived isolates, resulting in 34 isolates in total. Of these, 22 representative isolates underwent whole-genome sequencing. Phylogenetic analysis revealed the circulation of two major lineages. Isolates from Atyrau and West Kazakhstan clustered within the Trans-Eurasian (TEA/STI) lineage. Atyrau isolates formed a tight cluster differing by only 21-32 cgSNPs, consistent with a shared epidemiolocal source, whereas the West Kazakhstan isolate was highly divergent. Zhambyl and Almaty region belonged to the A.Br.Ames lineage but diverged into two distinct sublineages. Zhambyl region isolates demonstrated minimal divergence from the global reference genome Ames Ancestor, differing by only 16-31 SNPs. Almaty region isolates formed an endemic subclone, separated from the reference group by approximately 114 SNPs. Comparison with the Ames Ancestor and Sterne reference strains demonstrated substantial genetic divergence. CONCLUSION: Anthrax outbreaks in Kazakhstan during 2024 were primarily associated with livestock exposure and occurred within established endemic regions. Whole-genome sequencing revealed the coexistence of distinct TEA and Ames lineages, including evidence of persistent local transmission and long-term evolutionary stability of endemic B. anthracis populations. These findings enhance understanding of anthrax epidemiology in Central Asia and support the integration of genomic surveillance into national outbreak investigation programs.

Anthrax

Should neighbours of tuberculosis (TB) cases be prioritised for active case finding in high TB-burden settings? A prospective molecular epidemiological study.

INTRODUCTION: In high tuberculosis (TB)-burden countries, considerable transmission of Mycobacterium tuberculosis (M. tb) likely occurs outside of households. We aimed to estimate the TB prevalence and incidence in households and neighbourhoods around known TB cases and to understand transmission patterns. METHODS: Household and neighbourhood contacts of pulmonary TB index cases from contiguous areas in Bandung, Indonesia, were screened and followed up for 12 months. Sputum samples underwent smear microscopy, M. tb culture, Xpert MTB/RIF, DNA isolation and whole-genome sequencing (WGS). Pairwise single-nucleotide polymorphism (SNP) distance ≤12 defined transmission for pairs with known epidemiological links, or SNP≤3 for pairs without epidemiological link. An SNP=12 cut-off was used to characterise transmission clusters. RESULTS: From 213 index cases, 514 household and 4141 neighbourhood contacts underwent TB screening: 19 household (3.70%, 95% CI 2.24 to 5.71) and 45 neighbourhood (1.09%, 95% CI 0.79 to 1.45) contacts were identified with TB, of whom 18 (3.50%, 95% CI 2.20 to 5.48) and 38 (0.92%, 95% CI 0.65 to 1.13) respectively, were bacteriologically confirmed. During follow-up, 11 household and 13 neighbourhood contacts were identified with TB (incidence per 100 000 person-years: 2286 (95% CI 1286 to 4148) and 350 (95% CI 190 to 563)), of whom 6 and 8, respectively, were bacteriologically confirmed (incidence per 100 000 person-years: 1247 (95% CI 560 to 2776) and 201 (95% CI 101 to 402)). A total of 223 patient M. tb isolates underwent WGS. Of 15 intra-household pairs, 8 (53.3%) were transmission pairs. Of 24 neighbour to index case pairs, 1 (4.2%) was a transmission pair. 11 of 19 transmission pairs shared no epidemiological link. We identified 25 M. tb genetic clusters from 205 mono-TB isolates overall. CONCLUSION: Neighbours have lower prevalence and incidence of TB than household contacts, but twice as many cases. Very few received M. tb from their index case, suggesting uncontrolled community-wide transmission. Whole population active case finding may be necessary in high TB-burden settings.

Humans

Global diversity and evolution of Salmonella enterica serovar Panama: a genomic epidemiology study.

BACKGROUND: Non-typhoidal Salmonella is a globally important bacterial pathogen, typically associated with foodborne gastrointestinal infection. Some non-typhoidal Salmonella serovars can also colonise typically sterile sites in people to cause invasive non-typhoidal Salmonella disease. Salmonella enterica serovar Panama is responsible for a substantial number of cases of human bloodstream infection, but despite its global dissemination, numerous outbreaks, and a reported association with invasive non-typhoidal Salmonella disease, S enterica serovar Panama (S Panama) is understudied. We aimed to describe the genomic epidemiology and evolutionary history of S Panama to provide a vital baseline of understanding for this globally important serovar. METHODS: In this genomic epidemiology study, we analysed S Panama genomes derived from historical collections, national surveillance datasets, and publicly available epidemiological and whole-genome sequencing data which span the years 1931-2019. Maximum likelihood and Bayesian phylodynamic approaches were used to investigate population structure and evolutionary history and to infer geotemporal dissemination. A combination of different bioinformatic approaches with short-read and long-read data were used to characterise geographical and clade-specific trends in antimicrobial resistance (AMR) and genetic markers for invasiveness. FINDINGS: We analysed 836 S Panama genomes, of which 559 (67%) were sequenced as part of this study. The collection represents all inhabited continents and includes isolates collected between 1931 and 2019. We identified the presence of four geographically linked S Panama clades (C1 [ie, the Latin America and the Caribbean clade; n=338], C2 [ie, the European clade; n=124], C3 [ie, the Martinique clade; n=131], and C4 [ie, the Asia and Oceania clade; n=104]) and regional trends in AMR profiles. Most isolates (715 [86%] of 836) were pan-susceptible to antibiotics and belonged to clades circulating in Latin America and the Caribbean (64%, n=458). Most antibiotic-resistant isolates in our collection (113 [93%] of 121) fell within clades C4 (ie, the Asia and Oceania clade) and C2 (ie, the European clade), the latter of which had the highest invasiveness index values based on the conservation of 196 extraintestinal predictor genes. INTERPRETATION: This first large-scale phylogenetic analysis of S Panama has revealed important information about the population structure, AMR, global ecology, and genetic markers of invasiveness of the identified genomic subtypes. Our findings provide an important baseline for understanding S Panama infection. The presence of multidrug-resistant clades with elevated invasiveness index values should be monitored through ongoing surveillance, as such clades could pose an increased public health risk. FUNDING: UK Research and Innovation Global Challenges Research Fund and Biotechnology and Biological Sciences Research Council, UK Medical Research Council, Wellcome Trust, John Lennon Memorial Scholarship, Institut Pasteur, Santé publique France, Fondation Le Roch-Les Mousquetaires, Investissement d'Avenir Programme, and Australian National Health and Medical Research Council.

Humans

Invasive Streptococcus dysgalactiae subspecies equisimilis compared with Streptococcus pyogenes in Australia, 2011-23, and the emergence of a multi-continent stG62647 lineage: a retrospective clinical and genomic epidemiology study.

BACKGROUND: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is closely related to Streptococcus pyogenes, with overlapping disease manifestations. We compared the clinical and genomic epidemiology of invasive SDSE with invasive S pyogenes across different settings in Australia and phylogenetically contextualised the SDSE sequences within a global cohort of genomes. METHODS: In this retrospective clinical and genomic epidemiology study, cases of invasive SDSE isolated from normally sterile sites were identified and whole-genome sequenced across five hospital networks in temperate southeast Australia (Melbourne and Sydney) and the tropical Top End of the Northern Territory. SDSE disease incidence, case demographics, clinical outcomes, and longitudinal lineage dynamics were compared between southeast Australia and the Top End and to co-collected invasive S pyogenes cases in each region. SDSE genomes and lineages were also contextualised within 1166 global SDSE sequences. Genomic transmission clusters (not necessarily direct transmission) were inferred between isolates from different individuals by single-linkage clustering at a single nucleotide polymorphism threshold of less than or equal to seven for SDSE and less than or equal to five for S pyogenes based on previous transmission analyses. FINDINGS: Between Jan 1, 2011, and Feb 28, 2023, there were 693 invasive SDSE cases and 995 invasive S pyogenes cases. Invasive SDSE occurred almost exclusively in adults. The overall invasive SDSE incidence in southeast Australia was similar to invasive S pyogenes (incidence rate ratio [IRR] 1&#xb7;15, 95% CI 0&#xb7;91-1&#xb7;46; p=0&#xb7;26) and increased over the study period (IRR 1&#xb7;06 per year, 95% CI 1&#xb7;05-1&#xb7;08; p<0&#xb7;0001) from 1&#xb7;30 cases per 10&#x2009;000 admissions in 2011 to 3&#xb7;72 cases per 10&#x2009;000 admissions in the first 2 months of 2023 (95% CI 2&#xb7;13-6&#xb7;07). In southeast Australia, where stringent COVID-19 non-pharmaceutical interventions (NPIs) were implemented between 2020 and 2021, the SDSE incidence plateaued during 2020-21 but did not significantly decline (IRR 1&#xb7;09 compared with 2017-19, 95% CI 0&#xb7;88-1&#xb7;35; p=0&#xb7;47). By contrast, S pyogenes incidence substantially declined in 2020-21 in southeast Australia (IRR 0&#xb7;35 compared to 2017-19, 95% CI 0&#xb7;22-0&#xb7;52; p=0&#xb7;017). In the Top End, SDSE incidence was lower than S pyogenes (IRR 0&#xb7;24, 95% CI 0&#xb7;19-0&#xb7;31; p<0&#xb7;0001). However, crude incidence remained higher than southeast Australia (crude IRR 1&#xb7;24, 95% CI 1&#xb7;07-1&#xb7;42; p=0&#xb7;0037) and disproportionately affected First Nations Australians in the Top End compared with non-First Nations individuals (IRR 3&#xb7;36, 95% CI 2&#xb7;33-4&#xb7;85; p<0&#xb7;0001). Comparing 2020-21 with 2017-19, there was no decline in SDSE (IRR 1&#xb7;27, 95% CI 0&#xb7;73-2&#xb7;24; p=0&#xb7;45) or S pyogenes (IRR 0&#xb7;97, 95% CI 0&#xb7;80-1&#xb7;18; p=0&#xb7;81) incidence in the Top End, which did not implement prolonged stringent COVID-19 NPIs. Analysing the available genomes of invasive cases and in lineages for which more than or equal to five invasive cases occurred, only 24 (6%) of 384 SDSE cases were assigned to genomic transmission clusters, compared with 271 (52%) of 524 S pyogenes cases. An stG62647 lineage encompassed 113 (26%) of 436 sequenced SDSE genomes. Analysis of available SDSE sequences from Australia, western Europe, and North America inferred concurrent international expansion of the stG62647 lineage in all three regions between 1990 and 2005. INTERPRETATION: We identified a substantial burden of invasive SDSE, dominated by the emergent stG62647 lineage. The contrasting epidemiology between species in the different Australian regions, during COVID-19 NPIs, and genomic infection patterns indicates transmission dynamic, pathogen population, and host-pathogen interaction differences between SDSE and S pyogenes and indicates implications for disease control measures. FUNDING: Australian National Health and Medical Research Council.

Humans

Global gut microbiome atlas identifies epidemiologic-stage-specific signatures in inflammatory bowel disease.

The global rise of inflammatory bowel disease (IBD) reflects environmental shifts, yet how these changes are embedded in the gut microbial ecology remains unclear. We construct a microbiome atlas comprising 245,627 profiles. By classifying countries into three epidemiologic stages, we establish a framework. As the IBD burden increases, the gut microbial alpha diversity declines, and community structures form distinct clusters. This transition is characterized by a gradient of core genera. Integrating six shotgun metagenomic cohorts, we identify the depletion of anabolic pathways in IBD patients. Strain-level analysis reveals that epidemiologic staging shapes genetic architecture within species, identifying an IBD-enriched subclade of Eisenbergiella associated with elevated fecal cholic acid. We develop a microbial inflammatory risk score (MIRS), based on 19 genera, that discriminates IBD from controls (area under the curve [AUC] = 0.92). MIRS correlates with IBD prevalence. Our study provides an atlas linking epidemiology to microbiome ecology and strain evolution, offering a foundation for population-level surveillance and interventions in IBD.

Humans

Clinical, epidemiological, and genomic evidence on mpox in mainland China, 2022-2025: a scoping review.

BACKGROUND: Since 2022, mpox has expanded globally with sustained human-to-human transmission and increasing evidence of MPXV genomic diversification. In mainland China, mpox evidence has accumulated rapidly, but clinical, epidemiological, and genomic findings remain fragmented. METHODS: We conducted a scoping review of PubMed, CNKI, and WanFang databases up to March 2, 2026, and integrated literature-derived evidence with public MPXV sequences from GenBank, GenBase, and GISAID. Literature-derived data were used to map clinical-epidemiological characteristics, study-level genomic evidence, sequencing coverage, and reported lineage distribution. Curated public MPXV sequences were used for phylogenetic reconstruction, amino acid mutation profiling, and APOBEC-like substitution analysis. RESULTS: Fifty-eight studies were included: 32 addressed clinical or epidemiological evidence only, 25 addressed genomic evidence only, and one contributed to both domains. Fourteen hospital-based studies summarized 951 cases, showing that reported cases were concentrated among young adult men, with frequent MSM exposure (798/897, 89.0%; 95% CI 86.7-90.9%) and HIV co-infection (469/951, 49.3%; 95% CI 46.1-52.5%). Public sequence curation identified 231 unique mainland China MPXV sequences, of which 230 were used for phylogenetic and mutation analyses. Literature-based genomic evidence comprised 26 genomic studies, 37 study-level genomic records, and 31 reported-case units, including 414 sequenced cases among 530 reported cases (78.1%; 95% CI 74.4-81.4%). Clade IIb predominated among sequenced cases (412/414, 99.5%; 95% CI 98.3-99.9%), with C.1.1 and C.1 most frequently represented. Within the available dataset, public genomes represented multiple lineages and were unevenly distributed across regions and time. Mutation analysis revealed dispersed amino acid variation and a predominance of G>A and C>T transitions (73.0%). After collapsing recurrent substitutions to unique genomic sites, the proportion of G>A/C>T transitions decreased to 35.8% and further to 17.8% under a strict APOBEC3 motif definition, indicating that the observed mutation spectrum includes both shared lineage-associated substitutions and sequence-context-based APOBEC-like patterns. CONCLUSION: Available evidence indicates multi-lineage MPXV circulation and in mainland China, but interpretation remains constrained by uneven sequencing and lack of individual-level clinical-genomic linkage. Integrated genomic surveillance and standardized data linkage are needed to better characterize MPXV transmission and evolution.

APOBEC&#x2011;like substitutions

The reporting and handling of missing data in genetic epidemiological studies of mental health in childhood and adolescence: A systematic review.

BACKGROUND: Genetic epidemiological analyses of child and adolescent mental health often use data from prospective longitudinal cohorts. Missingness due to selective attrition is therefore an important potential source of bias in such analyses. Informatively reporting on missingness and taking appropriate steps to handle it in analyses can mitigate this potential bias. Here, we aim to systematically assess how researchers report and address missingness in genetic epidemiological studies of child and adolescent mental health-related outcomes using cohort data. METHODS: We systematically searched the Ovid Medline database for studies published between August 2012 and August 2025, reporting polygenic score, genome-wide association, or Mendelian randomization analyses, of data on children or adolescents participating in cohort studies. We extracted information from eligible studies based on criteria adapted from the strengthening and reporting of observational studies in epidemiology (STROBE) guidelines. RESULTS: A total of 133 eligible studies were included, of which 125 (93.98%) reported the number of complete cases in all waves, while 84 (63.16%) detailed the amount of missingness on all key variables. Most studies used complete case analysis, while 39 studies explicitly reported applying other methods to handle missingness, with multiple imputation (n&#xa0;=&#xa0;20, 15.04%) being the most common, followed by full information maximum likelihood 10 (8.1%). Only 18 studies (13.53%) reported an assumed missing mechanism along with the method used to address missingness. Full reporting of both the extent and handling of missingness at the item level was rare, occurring in only 5 (3.76%) and 15 (11.28%) studies, respectively, among the 123 studies that used multi-item instruments. CONCLUSION: Best practice recommendations for reporting on missing data handling emphasize the importance of detailing the proportion of missingness, types of mechanisms underpinning missingness, and details of approaches used. Based on this review, these recommendations for proper reporting of missing data are rarely followed in full.

children and adolescents

A Strain of Mycoplasma hominis Causing Pleuropneumonia Infection in an Immunocompetent Patient and Recent Epidemiological Trends: Implications for Clinical Management.

Mycoplasma hominis (M. hominis) is an opportunistic pathogen linked to urogenital and neonatal infections; however, limited genetic and epidemiological data are available. Extragenital infections in healthy adults are rare, and effective antibiotics are species-specific, complicating diagnosis and treatment. Hence, this study aimed to elucidate the clinical process, update the epidemiological characteristics, and investigate the genomic features of a fluoroquinolone-resistant M. hominis isolate from an immunocompetent patient with pleuropneumonia in China. The M. hominis&#xa0;isolate ZY_MH01 was recovered from pleural fluid and was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Whole Genome Sequencing (WGS). The completed genome was annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). Snippy v4.4.5 was utilized to conduct a core genome single nucleotide polymorphism (cgSNP) analysis between ZY_MH01 and 144&#xa0;M. hominis strains from the NCBI GenBank database. Subsequently, phylogenies were constructed using IQ-TREE v3.1.2 and visualized by iTOL. Antimicrobial resistance determinants were identified using strict criteria of Comprehensive Antibiotic Resistance Database (CARD) RGI 6.0.5 (Web portal) and broth microdilution test. Virulence genes were screened using Abricate v1.0.1 against the Virulence Factor Database (VFDB). A total of 42 strains (including ZY_MH01) from Genbank with an assembly level of Complete or Chromosome were re-annotated using Prokka v1.2.0 and pangenome analysis was performed using the Roary. The core genome constitutes only 17.1%, which may contribute to the unusually high level of polymorphism observed among M. hominis strains. No antibiotic resistance genes or virulence genes were detected in the genome of ZY_MH01. However, some resistance-associated mutations of gene parC and gyrA in the Quinolone Resistance Determining Region (QRDR) were identified. Phylogenetic analysis indicates that strains originating from the same geographic region typically exhibit reduced genetic distances; this trend is especially pronounced in regions with a higher number of publicly available strain sequences. In specific circumstances, when conventional broad-spectrum antibiotics are ineffective, even immunocompetent patients should consider the possibility of M. hominis infection. This study presents a detailed account of the diagnostic and therapeutic course of a pleuropneumonia infection caused by M. hominis in an immunocompetent patient, and performs an epidemiological analysis of all M. hominis sequences that have been recently made publicly available.

Humans

Emerging terbinafine-resistant Trichophyton indotineae between 2018 and 2023: a multinational genomic epidemiology study.

BACKGROUND: Trichophyton species cause the greatest burden of dermatophytosis worldwide, with the Trichophyton mentagrophytes species complex being particularly associated with the emergence of new aggressive infections. One emerging species, Trichophyton indotineae is notable for its clinical resistance to terbinafine antifungal treatment and rapid global spread. In this study we aim to characterise the epidemiology of this emerging pathogen using genomics. METHODS: In this retrospective genomic epidemiology study, to better understand the epidemiology of this disease, we sourced isolates collected from patients with severe cases of dermatophytosis (identified either by internal transcribed spacer sequencing or phenotypic characterisation) in the UK, Ireland, France, Canada, and India for the period 2014-23, including the T indotineae type strain from Japan. We used whole-genome sequencing to confirm 90 isolates were T indotineae, and antifungal susceptibility testing to assess susceptibility to terbinafine. FINDINGS: 103 cases of severe dermatophytosis caused by Trichophyton species collected between 2018 and 2023 in the UK, France, Canada, Ireland, and India were included in this study. Susceptibility testing indicated that 63 (70%) of 90 T indotineae isolates were resistant to terbinafine (minimum inhibitory concentration [MIC] &#x2265;0&#xb7;5 mg/L). Pairwise genetic distances showed very high identity with only 147 (range 1-414) single-nucleotide polymorphisms (SNPs) separating isolates that were nested within a monophyletic phylogeny, supporting a single evolutionary origin of T indotineae. Genome-wide analyses identified multiple non-synonymous SNPs in SQLE (ERG1), the squalene epoxidase target of terbinafine, that were associated with terbinafine in vitro resistance of 0&#xb7;5 mg/L or higher. However, six isolates exhibited high MIC values without SQLE mutations, suggesting the presence of alternative resistance mechanisms. INTERPRETATION: That no clear geographical clustering of isolates was observed confirms the rapid transcontinental spread of T indotineae from its likely centre of diversity in Asia. Our findings highlight the importance of better genomic surveillance to understand and manage this severe and rapidly emerging terbinafine-resistant dermatophyte. FUNDING: None.

Terbinafine

Persistent spread of carbapenemase-producing Klebsiella pneumoniae in acute care hospitals in 36 European countries (the CCRE survey): a prospective, multicentre, cross-sectional, epidemiological, microbiological, and genomic surveillance study.

BACKGROUND: Carbapenem-resistant Enterobacterales pose a substantial threat to patients and health-care systems. We conducted a survey of carbapenem-resistant and/or colistin-resistant Enterobacterales (CCRE survey) in 37 European countries to describe their occurrence, geographical distribution, and population dynamics and inform control policies. We report the results of Klebsiella pneumoniae species complex isolates in this study. METHODS: In this cross-sectional, epidemiological, microbiological, and genomic study conducted in all EU, European Economic Area and EU candidate countries as of 2019, hospital microbiology laboratories were selected on the basis of population coverage. Participating laboratories collected, from patient samples, the first ten successive isolates of carbapenem-resistant or carbapenem-susceptible increased exposure (carbapenem-R/I) K pneumoniae species complex or Escherichia coli, and carbapenem-susceptible (carbapenem-S) comparator isolates of the same species, accompanied by patient epidemiological and clinical information. Isolate collection started in 2019, with three possible starting dates-ie, March 1, April 1, or May 1, 2019, and ended after collection of ten carbapenem-R/I and carbapenem-S isolates or a maximum period of 6 months. Isolates were tested for phenotypic susceptibility to 16 antimicrobial agents of relevance to K pneumoniae species complex. Whole-genome sequencing was performed centrally using Illumina technology. Isolates from the CCRE survey were compared with those from the European Survey of Carbapenemase-Producing Enterobacteriaceae (EuSCAPE) study. FINDINGS: 1566 carbapenem-R/I and 1407 carbapenem-S K pneumoniae species complex isolates collected from patients in 302 hospitals in 36 countries (one country did not send isolates) were analysed in this study. The high-risk lineages identified during a previous similar survey in 2013-14 (EuSCAPE) were found to continue to circulate across European hospitals in 2019 (ST11, ST15, ST101, and ST258/512). Moreover, concerning shifts in the pathogen population were observed. First, a higher proportion of carbapenem-R/I isolates was found to carry a carbapenemase gene in the CCRE survey (1398 [89&#xb7;3%] of 1566) than in EuSCAPE (657 [69&#xb7;6%] of 944), mainly related to increased acquisition of carbapenemase genes by high-risk lineages. Of note, among ST307 isolates from all hospitals, the proportion of carbapenem-R/I isolates carrying a carbapenemase gene increased from 14 (60&#xb7;9%) of 23 in EuSCAPE to 164 (91&#xb7;1%) of 180 in the CCRE survey. Second, an expansion of emerging multidrug-resistant lineages (ST147, ST307, and ST39) was also noted: Among 113 hospitals that contributed K pneumoniae species complex isolates to both EuSCAPE and the CCRE survey, the proportion of ST147 increased from 16 (3&#xb7;4%) of 476 in EuSCAPE to 49 (7&#xb7;4%) of 662 carbapenem-R/I isolates in the CCRE survey, that of ST307 increased from 15 (3&#xb7;2%) of 476 to 88 (13&#xb7;3%) of 662, and that of ST39 increased from 3 (0&#xb7;6%) of 476 to 10 (1&#xb7;5%) of 662. Third, there was an increased spread of isolates harbouring acquired virulence loci: isolates with the highest Kleborate virulence score of five increased from 7 (0&#xb7;4%) of 1717 in EuSCAPE to 40 (1&#xb7;3%) of 2973 in the CCRE survey. Notably, the increase was mainly observed in the carbapenem-S-group. INTERPRETATION: The survey findings portray an escalating epidemiological situation and suggest that control measures have not been able to interrupt transmission of high-risk lineages of carbapenemase-producing K pneumoniae in European hospitals. The heterogeneous and evolving situation with regards to circulating lineages and dominant carbapenemase genes requires strengthening and continuous adaptation of diagnostic, treatment, and control measures guided by genomic surveillance. FUNDING: European Centre for Disease Prevention and Control and Centre for Genomic Pathogen Surveillance.

Humans

Oropouche virus: viral evolution, epidemiological trends, and challenges for control.

PURPOSE OF REVIEW: In recent years, OROV has emerged as a significant public health threat beyond the Amazon region. Here we review current epidemiological, virological, clinical and ecological knowledge of OROV to inform health practitioners, public health authorities and the scientific community and to facilitate the development of effective control strategies for OROV. RECENT FINDINGS: We describe the epidemiological, virological, ecological and clinical characteristics of OROV, focusing on lessons from the recent expansion, and highlighting needs for control and management of this emerging arbovirus. SUMMARY: This review aims to inform health practitioners, public health authorities and the scientific community of the recent reemergence and expansion of OROV beyond the Amazon Basin. The ecology, epidemiology, virology of OROV and clinical presentations of OROV infection are discussed, and knowledge gaps are identified.

Humans

A Systematic Review of Spatial Epidemiological Modeling Approaches Applied During the COVID-19 Pandemic.

BACKGROUND: A wide range of epidemiological modeling approaches have been applied to the SARS-CoV-2 pandemic, which presents an opportunity to assess common approaches applied to specific research questions. Spatial models interrogate how heterogeneities and host movement dynamics influence local and regional patterns of disease, issues that were of great interest for understanding and controlling SARS-CoV-2. OBJECTIVE: Here we present a systematic review of spatial epidemiological modeling approaches of SARS-CoV-2. We describe common themes and highlight unique strategies, providing a foundation for researchers to devise spatial models most appropriate for future pathogens and epidemics. Our review also categorizes the research questions that were addressed with spatial models, highlights parameter estimation techniques, and describes the cyber infrastructure used for model development. METHODS: We conducted a systematic review using Web of Science and a standardized set of keywords, followed by thorough examination of abstracts and full texts to determine which studies met our inclusion criteria. To guide our description and comparisons of models, we developed a Geography, Population, Movement (GPM) framework that conceptualizes the interactions between three distinct subcomponents of any spatial model. The geographic model represents the physical arena in which the model is implemented, the intra-population model describes the transmission and disease processes that occur within distinct spatial units of the geography, and the movement model describes the algorithms that dictate how hosts move among spatial units within the geography. RESULTS: The search identified a total of 193 articles, of which 109 were included in our review. The most abundant intra-population modeling methods were agent-based (47.7%) and compartmental modeling (29.4%) approaches. Movement models ranged in complexity, with the most complex models implementing commuter movement among many points of interest in the geographic arena, which were sometimes parameterized by fine-scale mobility data. Geographic models ranged from describing microcosms, such as single classrooms, all the way up to multi-country models. Of the 63.3% of models studies that specified the programming language used, we detected ten different languages, with Matlab and Python being the most frequent, although only 30.6% of studies provided open-access code for their models. We also described eight specialized software systems that were used to construct agent-based or compartment models of COVID-19. CONCLUSIONS: Our review identified and characterized a variety of spatial modeling strategies and software that were usefully employed to address many relevant epidemiological questions for COVID-19. Future research is needed to quantitatively assess which modeling approaches are most appropriate in specific situations, to answer specific questions, or to apply to certain disease systems. Moreover, future cyberinfrastructure could help to modularize and standardize modeling approaches, which would increase transparency and reproducibility, and which would facilitate a detailed examination of which model attributes relate to model performance in a variety of contexts.

COVID-19

The SARS-CoV-2 Integrated Genomic Epidemiology Database (IGED): Linking viral genomes with patient-level metadata to advance statewide genomic surveillance in California.

In July 2021, the California Code of Regulations Title 17 required all laboratories performing SARS&#x2011;CoV&#x2011;2 whole genome sequencing (WGS) to report their sequencing results to the California Department of Public Health (CDPH). These viral genomic data and patient metadata were compiled into the Integrated Genomic Epidemiology Database (IGED). Linking anonymized viral sequences with patient&#x2011;level information enabled monitoring of infectiousness, pathogenicity, transmission dynamics, evolution, and vaccine evasion among emerging SARS&#x2011;CoV&#x2011;2 lineages. Laboratories performing SARS-CoV-2 WGS transmitted sequencing results to CDPH through Electronic Laboratory Reporting (ELR) and non-ELR pathways. CDPH applied uniform reporting requirements but allowed flexibility in specific data formats to accommodate diverse data systems. To preserve data quality and interoperability across heterogeneous sources, CDPH implemented standardization, validation, and deduplication protocols. Snowflake, a cloud&#x2011;based data storage and analytics platform, and Posit Connect, a cloud deployment and automation platform, supported the management, processing, and integration of data within the IGED. The IGED established links between SARS&#x2011;CoV&#x2011;2 WGS data and epidemiologic metadata for 801,418 sequences, representing 81.7% of all sequences reported in California. Lineages reported to the IGED showed strong concordance with lineage proportions in GISAID. Sequences reported to the IGED had average turnaround times longer than one month, and the majority of sequencing was performed in Southern California and Los Angeles. The IGED enhanced genomic surveillance through predictive modeling and monitoring concerning evolutionary trends such as recombination and saltations in persistent infections. Development of the IGED highlighted the need for standardized data requirements, sustained funding for sequencing, incentives for data submission, and interdisciplinary collaboration to build an effective genomic surveillance system. This framework for linking genomic and epidemiologic data has not only generated critical insights for SARS&#x2011;CoV&#x2011;2 but also provided the foundation for CDPH and other public health organizations to develop similar IGED&#x2011;like systems for other priority pathogens as genomic surveillance expands.

Journal Article