International Journal of Infectious Diseases最新文献

{"title":"32 years after pioneering prevention of mother-to-child HIV transmission in Europe: achievements, persistent inequities, and the imperative for a coordinated response.","authors":"Narcisse Elenga, Albert Faye, Jocelyne Adoissi, Pierre Frange","doi":"10.1016/j.ijid.2026.109199","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109199","url":null,"abstract":"<p><strong>Background: </strong>Over the past three decades, Europe has led efforts to prevent mother-to-child transmission of HIV, reducing transmission rates to below 1-2% in many Western and Northern countries. Universal antenatal screening, the early initiation of combination antiretroviral therapy, and integrated obstetric-HIV care have made paediatric HIV largely preventable.</p><p><strong>Main body: </strong>However, national averages obscure persistent inequities within the WHO European Region and inside individual countries. In Eastern Europe and Central Asia, late diagnosis, incomplete screening, and fragmented maternal health services continue to sustain preventable transmission. Even in Western Europe and its overseas territories, subnational and sociodemographic disparities challenge claims of elimination. Structural barriers, including delayed prenatal care, legal insecurity, language barriers, socioeconomic disadvantage, and fragile health systems, remain key determinants of risk. We argue that elimination must be defined not only by national indicators but also by equity, subnational accountability, and harmonised surveillance capable of identifying disparities within the same territory.</p><p><strong>Conclusion: </strong>A response is urgently needed to ensure HIV elimination in all populations.</p><p><strong>Clinical trial number: </strong>not applicable.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109199"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Humoral immune responses following inactivated COVID-19 vaccine with different booster intervals: a randomized interventional immunogenicity study.","authors":"Xinyu Liu, Qianhui Hua, Rongrong Dai, Lanxin Ma, Ruijing Bao, Huijun Lei, Pengfei Yu, Yuting Liao, Juan Yang, Huakun Lv, Jianmin Jiang, Hangjie Zhang","doi":"10.1016/j.ijid.2026.109196","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109196","url":null,"abstract":"<p><strong>Objectives: </strong>To evaluate the immunogenicity of booster doses at varying intervals after a two-dose primary series of inactivated COVID-19 vaccine.</p><p><strong>Methods: </strong>This randomized, open-label interventional study in Zhejiang, China, allocated 431 participants via stratified block randomization to a control group (primary series only) or booster groups at 1, 4, 6, or 11 months after the primary series. Laboratory staff and statisticians were blinded. Immunogenicity endpoints included anti-RBD IgG, live-virus microneutralization, and pseudovirus neutralization against wild-type, Delta, and Omicron BA.1.</p><p><strong>Results: </strong>At 1 month post-booster, live wild-type neutralizing antibody GMT (Geometric mean titer) increased with longer intervals, from 42.96 (1-Month group) to 149.93 (11-Month group). Anti-RBD and anti-S1+N IgG concentrations were significantly higher in the 4-, 6-, and 11-Month group. Pseudovirus neutralization inhibition percentages decreased progressively across variants: wild-type (72.81%-86.70%), Delta (24.32%-35.82%), Omicron BA.1 (0.26%-2.97%). GMT declined substantially by 6 months post-booster (12.08 and 17.95 in the 1- and 4-Month group), and age was significantly negatively associated with humoral responses only in the 6-Month group.</p><p><strong>Conclusions: </strong>All booster regimens elicited greater binding and neutralizing responses than the two-dose primary series, with peak responses at 1 month post-booster increasing progressively as the interval lengthened (up to 11 months). However, neutralizing activity against Omicron BA.1 was negligible across regimens, and antibody levels declined substantially by 6 months post-booster.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109196"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Randomized controlled trial of pirfenidone XR for patients with COVID-19 and exploration of effects on long-COVID incidence.","authors":"Tamez-Torres Karla M, Aguilar Laura Karina, Díaz-Mejía Bruno Alejandro, Morales-Ortega Maria de la Luz, Ramírez-González Luis E, Highstrete Ren, González-Cruz Adalberto S, Pérez-García Esteban, Hernández-Martínez Ingrid Vanessa, Hernández-Delgado Alejandra, Hernández-Aldana Nadiel, Gorgonio Pedro A, Núñez-Álvarez Carlos A, Hernández-Ramírez Diego F, Lara-García Eunice A, Rumoroso-García Jose Alfonso, Nava-Linares Angelica, Cervantes-Sánchez Axel, Chapa-Ibargüengoitia Mónica, Valdez-Vazquez Rafael R, Ponce-de León Alfredo, Aguilar-Cordova Estuardo, Aguilar Laura K, Kershenobich-Stalnikowitz David, Sifuentes-Osornio Jose","doi":"10.1016/j.ijid.2026.109186","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109186","url":null,"abstract":"<p><strong>Objective: </strong>Evaluate safety and efficacy of extended-release pirfenidone (pirfenidone-XR), an anti-inflammatory and anti-fibrotic agent, as an early treatment for acute and long-term effects of COVID-19.</p><p><strong>Methods: </strong>This double-blinded, placebo-controlled trial randomized hospitalized and ambulatory COVID-19 patients in Mexico City 2:1 to pirfenidone-XR or placebo. The primary endpoint was recovery dynamics using a clinical severity 7-point ordinal scale; secondary and exploratory endpoints included long COVID incidence and safety. Planned enrollment was 801 patients to detect a 50% relative-risk reduction in key clinical outcomes.</p><p><strong>Results: </strong>Between May 2020 and May 2021, 367 patients were enrolled, approximately 50% of the target. Evolving standards of care resulted in early termination and lower-than-anticipated event rates, limiting statistical power. Time-to-recovery analyses suggested improved dynamics with pirfenidone-XR: both groups had 53% full recovery by week 1; an additional 33% vs 21% achieved it during week 2, and 97% vs 90% by week 4. Long-term follow-up showed a numerically lower incidence of long COVID symptoms in 1, 2, 3 and 4 symptom domains in the pirfenidone-XR group: symptoms in ≥4 domains were reported in 5% vs 21% of hospitalized patients. There were no unexpected safety signals.</p><p><strong>Conclusions: </strong>Pirfenidone-XR was well tolerated and, although underpowered, demonstrated numerical trends of improved recovery and reduced long COVID risk. These findings support further investigation of pirfenidone-XR in patients infected with SARS-CoV-2 and similar post-infectious syndromes characterized by persistent immune activation and tissue remodeling.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109186"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical and serological outcomes for successive syphilis episodes in people with HIV.","authors":"José L Casado, Ana Moreno, Mario Rodríguez-Domínguez, Beatriz Romero-Hernández, Isabel Izuzquiza, Pilar Vizcarra, Laura Luna, Alejandro Vallejo","doi":"10.1016/j.ijid.2026.109201","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109201","url":null,"abstract":"<p><strong>Background: </strong>Syphilis incidence continues to rise globally among people with HIV (PWH), in whom repeated episodes are common and contribute to ongoing transmission. Whether prior infections modify clinical presentation, serological response, or treatment outcomes remains poorly understood. Partial immunity against Treponema pallidum has been proposed, but its clinical relevance across successive episodes has not been evaluated in a prospective cohort. The objective was to compare clinical presentation, time to serological response, serofast status, and seroreversion across successive syphilis episodes in PWH.</p><p><strong>Methods: </strong>Prospective cohort study of adult PWH diagnosed with a confirmed first syphilis episode and subsequent syphilis episodes between January 2016 and December 2024. The primary endpoint was serological response, defined as a ≥4-fold RPR (rapid plasma reagin) titer decline or seroreversion before or at 12 months after treatment; episodes with reinfection before 12 months were excluded. Successive episodes were defined as confirmed reinfections, a ≥4-fold RPR rise after serological response, and they were compared using survival and regression models.</p><p><strong>Results: </strong>We evaluated 362 syphilis episodes in 183 PWH over 1,445 person-years of follow up. In repeated episodes (1^st vs 2^nd vs ≥ 3), a secondary syphilis stage was less frequent (21% vs 11% vs 13%: p=0.048). Serological response at 12 months was similar in repeated episodes (75%, 83%, and 78%), associated with a high RPR titer and higher nadir CD4+ count (RR 1.004; p=0.047). A shorter inter-episode interval correlated with a faster serological response in the following episode (rho=0.226; p=0.029). Serofast status was more frequent in successive episodes than in the first (33%, 62%, and 64%; p<0.001), and inversely less for seroreversion (57%, 32%, and 20%; p<0.001), after adjusting by time of follow up. A final diagnosis of neurosyphilis was made in 4%, 1%, and no cases, respectively.</p><p><strong>Conclusions: </strong>Non-treponemal test titers and serological response rates at 12 months are consistent across successive syphilis episodes in PWH. An attenuation of secondary-stage presentation, a shorter inter-episode interval associated with a faster subsequent serological response, and a progressive rise in serofast status not attributable to treatment failure or neurosyphilis are findings compatible with, though not direct evidence of, partial immune memory.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109201"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Herpes Zoster Vaccination in Patients with Immune-Mediated Inflammatory Diseases: A Systematic Review and Meta-Analysis of Vaccine Efficacy, Effectiveness, and Safety.","authors":"Sukamto Koesnoe, Evy Yunihastuti, Alvina Widhani, Suzy Maria, Anshari Saifuddin Hasibuan, Bramantya Wicaksana, Diski Saisa, Utariny Nurin Nasywa, Indira Laksmi Maharani","doi":"10.1016/j.ijid.2026.109198","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109198","url":null,"abstract":"<p><strong>Background: </strong>Patients with immune-mediated inflammatory diseases (IMIDs) are at increased risk of herpes zoster (HZ) due to immune dysregulation and immunosuppressive therapy. This systematic review aimed to evaluate the vaccine efficacy/effectiveness (VE) and safety outcomes of the HZ vaccine in patients with IMIDs.</p><p><strong>Methods: </strong>PubMed, Cochrane Library, and Scopus were searched for clinical trials and cohort studies evaluating recombinant zoster vaccine (RZV) or zoster vaccine live (ZVL) in adults with IMIDs. Effect sizes were expressed as VE% and risk ratio (RR) with 95% confidence intervals (CIs). Random-effects meta-analyses used restricted maximum likelihood estimation.</p><p><strong>Results: </strong>Twenty-six studies involving 2,238,638 patients with various IMIDs were included. RZV efficacy was 90.5% (69.1%-97.1%), while effectiveness was 59.0% (49.8%-66.5%). ZVL effectiveness was 42.4% (37.1%-47.3%). RZV reduced post-herpetic neuralgia, with VE of 33.6% (11.7%-50.0%). Disease flares were not increased significantly in RZV (RR 1.05 [0.91-1.22]) and ZVL (RR 1.29 [0.69-2.43]). Reactogenicity and systemic adverse events were more frequent following HZ vaccination, particularly with RZV.</p><p><strong>Conclusion: </strong>HZ vaccination, especially RZV, effectively prevents HZ in patients with IMIDs and is generally well tolerated. These findings support RZV use while emphasizing individualized assessment of vaccination timing and immunosuppressive treatment. Further studies should examine long-term effectiveness and safety across IMID subtypes and immunosuppressive regimens.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109198"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recovery of Human Pegiviruses from Patients with Acute Febrile Illness and Sub-acute Central Nervous System Infection.","authors":"Sofiati Dian, Edison Johar, Diah Witari, Ida Yus Sriyani, Yora Permata Dewi, Ungke Antonjaya, Ahmad Rizal Ganiem, Frilasita Aisyah Yudhaputri, Reinout van Crevel, Sri Masyeni, Jeremy P Ledermann, Ann M Powers, Eric C Mossel, Khin Saw Aye Myint","doi":"10.1016/j.ijid.2026.109200","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109200","url":null,"abstract":"<p><strong>Objective: </strong>To describe two cases of HPgV-1 identified during high-throughput sequencing (HTS)-based investigation of previously undiagnosed acute febrile illness (AFI) and central nervous system infection.</p><p><strong>Methods: </strong>RNA metagenomic HTS was applied to clinical samples that had previously tested negative by PCR targeting alphaviruses, flaviviruses, enteroviruses, herpesviruses, and paramyxoviruses. Specimens were also tested for IgM antibodies against chikungunya virus, dengue virus, and Japanese encephalitis virus.</p><p><strong>Results: </strong>A complete HPgV-1 genotype 4 was recovered from a child with undifferentiated AFI. In a middle-aged man with HIV and severe neurological disorder, complete genomes of HPgV-1 (genotype 4), HPgV-2, and hepatitis C virus (genotype 3k) were identified.</p><p><strong>Conclusion: </strong>To our knowledge, this is the first report of HPgV-2 detection in Indonesia, expanding its known geographic distribution. These findings underscore the complexity of viral co-infections in immunocompromised patients and the uncertain clinical significance of human pegiviruses. This further highlights the utility of metagenomic HTS for pathogen discovery and genomic surveillance in unexplained clinical syndromes.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109200"},"PeriodicalIF":4.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149223984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic Epidemiology and Resistance Mechanisms of PER-Type Extended-Spectrum β-Lactamases in Proteus mirabilis.","authors":"Lianyan Xie, Kang Xu, Linlin Xu, Qing Chen, Rong Xu, Jingyong Sun","doi":"10.1016/j.ijid.2026.109191","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109191","url":null,"abstract":"<p><strong>Background: </strong>PER-type extended-spectrum β-lactamases can compromise newer β-lactam/β-lactamase inhibitor combinations, but their dissemination and resistance phenotypes in Proteus mirabilis remain incompletely understood.</p><p><strong>Methods: </strong>We screened 118 consecutive, non-duplicate ceftazidime-resistant P. mirabilis isolates collected at a Shanghai tertiary hospital from January 2023 to March 2025. The 17 bla_PER-positive isolates underwent susceptibility testing, hybrid sequencing, cloning, Ambler S130T/T216S mutagenesis, RT-qPCR, structural modelling, phylogenetic analysis, and long-read analysis.</p><p><strong>Results: </strong>Seventeen isolates carried bla_PER (14.4%; 95% CI, 9.2%-22.0%): bla_PER-1 (n = 6), bla_PER-13 (n = 9), or bla_PER-4 (n = 2); 14 belonged to ST135 and 14 loci were chromosomal. All bla_PER loci were associated with ISCR1-containing complex class 1 integrons containing IS26. Across 17 study isolates and 34 public genomes, bla_PER-1 and bla_PER-4 occurred in multiple lineages, whereas the study's bla_PER-13 isolates belonged to ST135. The two bla_PER-4 plasmids and CP196196.1 were identical across 100% bidirectional coverage in three STs. Long reads resolved heterogeneous ISCR1-associated arrays and IS26-associated arrays. In matched constructs, S130T reproduced the PER-4 MIC profile; T216S matched PER-13 but did not change parental PER-1 MICs. Exploratory RT-qPCR detected no significant difference among allele groups. Ambler residue 130 was located near the active site.</p><p><strong>Conclusions: </strong>bla_PER-13 was the most frequent allele within this selected ceftazidime-resistant collection. bla_PER-4 conferred the highest MICs to several newer β-lactam/β-lactamase inhibitor combinations, and matched mutagenesis supported Ambler S130T as a major determinant of this phenotype; exploratory transcript measurements did not indicate markedly increased PER transcript abundance but could not exclude biological variation. The occurrence of an identical bla_PER-4 plasmid in distinct STs, together with lineage-associated chromosomal bla_PER backgrounds and heterogeneous ISCR1- and IS26-associated arrays, indicates that clonal expansion, plasmid dissemination, and local structural variation jointly shape bla_PER persistence and resistance in P. mirabilis.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109191"},"PeriodicalIF":4.6,"publicationDate":"2026-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repeat antimicrobial susceptibility testing of serial bacterial isolates: clinical utility and diagnostic stewardship.","authors":"Tokeshwar Kumar Sahu, Pravin Gadkari, Jaishriram Rathored","doi":"10.1016/j.ijid.2026.109193","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109193","url":null,"abstract":"<p><strong>Objectives: </strong>To synthesize evidence on the interpretation and temporal stability of antimicrobial susceptibility profiles in serial bacterial isolates and to identify factors that inform repeat testing within diagnostic stewardship.</p><p><strong>Methods: </strong>This narrative review integrates evidence from studies of serial clinical isolates with data on analytical variability, within-host resistance evolution, heteroresistance, antimicrobial exposure, and diagnostic stewardship.</p><p><strong>Results: </strong>Susceptibility profiles are generally stable over short intervals, although clinically relevant changes vary according to bacterial species, antimicrobial agent, specimen context, and elapsed time. Small MIC shifts, particularly near clinical breakpoints, may result in categorical discordance without indicating true resistance emergence. Pseudomonas aeruginosa exhibits greater short-term phenotypic variability than several other common pathogens. Repeat AST is most strongly supported when infection persists or recurs, the clinical response is inadequate, antimicrobial exposure may have selected for resistance, or the consequences of missed resistance are substantial. In selected lower-risk settings, referral to a recent susceptibility result may be appropriate, provided that laboratory and clinical override mechanisms remain available.</p><p><strong>Conclusions: </strong>Short-term susceptibility stability may support conservative referral to a recent AST result, but the degree of instability varies by organism, antimicrobial agent, and specimen context. Where a single operational interval is required, laboratories may adopt the shortest interval supported by local or otherwise applicable evidence, with predefined overrides for higher-risk clinical situations. Prospective multicentre validation is required before specific intervals can be generalized across clinical and laboratory settings.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109193"},"PeriodicalIF":4.6,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149216016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reemergence of DENV-3III_C.1 and emergence of DENV-3III_B.3.2 in Ecuador: multiple introductions and dispersal patterns, 2022-2026.","authors":"Sully Márquez, Lizeth Salazar, Gabriela Echeverría-Garcés, Diana Gutiérrez-Pallo, Gabriel Trueba, Joseph N S Eisenberg, Josefina Coloma, Andrés Carrazco-Montalvo","doi":"10.1016/j.ijid.2026.109189","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109189","url":null,"abstract":"<p><p>We characterized the reemergence of DENV-3III_C.1, the emergence of DENV-3III_B.3.2, and their phylogeographic spread in Ecuador during 2022-2026 through integrated epidemiologic and genomic surveillance. Lineage DENV-3III_C.1 formed a monophyletic Ecuadorian cluster closely related to Colombian viruses. The earliest sampled Ecuadorian sequence was detected in Esmeraldas, compatible with a possible introduction across the northern border followed by within-country dissemination. Lineage DENV-3III_B.3.2 comprised multiple Ecuadorian clades related to viruses from Colombia, Cuba, and the United States (travel-associated), consistent with independent introductions followed by geographic expansion. These findings reveal distinct transmission histories and support strengthened genomic surveillance at border crossings and other key points of entry.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109189"},"PeriodicalIF":4.6,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149215957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-canonical global dissemination of the influenza A(H3N2) K lineage during the 2025-2026 influenza season.","authors":"Lirong Cao, Yan Li, Hong Zheng, Jinghe Fang, Xiangyu Zeng, Shimin Su, Jingzhi Lou, Caiqi Liu, Zhihui Zhang, Shi Zhao, Daqi Yu, Marc Ka Chun Chong, Maggie Haitian Wang","doi":"10.1016/j.ijid.2026.109188","DOIUrl":"https://doi.org/10.1016/j.ijid.2026.109188","url":null,"abstract":"<p><strong>Background: </strong>Seasonal influenza A(H3N2) exhibits rapid global lineage turnover driven by continuous antigenic evolution. However, the emergence of newly dominant H3N2 lineages remains incompletely understood.</p><p><strong>Methods: </strong>We combined large-scale genomic surveillance with phylogenetic reconstruction, temporal mutation dynamics analyses, geographic dissemination analyses, and structural characterization to investigate emergence and global expansion of the H3N2 K lineage. A total of 170,793 complete human H3N2 hemagglutinin (HA) sequences collected globally between 1992 and 2026 were retrieved from GISAID.</p><p><strong>Results: </strong>We found that the K lineage rapidly replaced previously co-circulating H3N2 J.2 sublineages within a single influenza season. Its global expansion was associated with a non-canonical dissemination pattern centered on the United States rather than the traditional East-Southeast Asia (E-SEA) source system. Temporal mutation dynamics analyses of global surveillance data showed that K-lineage-defining substitutions were first detected in the United States and Japan. Despite accumulation of multiple antigenic-site substitutions, structural analyses suggested preservation of overall HA structural stability, with differential compatibility across pre-existing antibodies rather than complete antibody escape.</p><p><strong>Conclusions: </strong>Our findings expand current understanding of how globally dominant H3N2 variants emerge and suggest that geographically distributed evolutionary assembly may represent an important pathway in contemporary influenza evolution.</p>","PeriodicalId":14006,"journal":{"name":"International Journal of Infectious Diseases","volume":" ","pages":"109188"},"PeriodicalIF":4.6,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149216041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}