Débora B Goulart, Carine K Souza, Giovana C Zanella, Celeste A Snyder, Janice C Zanella, Alexey Markin, Bailey Arruda, Tavis K Anderson, Amy L Baker
Background: The USDA influenza A virus in swine national surveillance plan identified an increase in the detection frequency of a group of swine 1A.1.1.3 hemagglutinin (HA) clade viruses. This change was associated with reassortment events that resulted in new neuraminidase (NA) gene pairings. We hypothesized that the new N1 genes improved the transmission efficiency of the virus.
Methods: We assessed the pathogenesis and transmission of four H1 1A.1.1.3 swine strains paired with different NA subtypes and lineages, all of which shared similar internal gene constellations.
Results: There was little variation in the titers of viral nasal shedding across the groups, and the different surface protein pairings had no effect on transmission efficiency. All IAV strains, reflecting both pre- and post-reassortment genetic patterns, were transmitted to naïve indirect contact pigs.
Conclusions: These data indicate that the combinations of 1A.1.1.3 HA with NA subtypes had little impact on transmission. These findings suggest that the increased detection of the H1 1A.1.1.3 clade in the United States was unlikely directly due to altered replication, transmission, or antigenic drift, but perhaps due to changes in population immunity resulting from differential vaccine use or prior exposure, variations in production practices, or ecological conditions.
背景:美国农业部猪流感病毒国家监测计划确定了一组猪A.1.1.3血凝素(HA)进化枝病毒的检测频率增加。这种变化与导致新的神经氨酸酶(NA)基因配对的重组事件有关。我们假设新的N1基因提高了病毒的传播效率。方法:对具有相似内部基因群的4种不同NA亚型和谱系的猪H1 1A.1.1.3毒株的发病机制和传播进行了研究。结果:病毒滴度在各组间差异不大,不同表面蛋白配对对传播效率无影响。所有IAV毒株,反映了重组前和重组后的遗传模式,都传播给naïve间接接触猪。结论:这些数据表明a .1.1.3 HA与NA亚型的组合对传播影响不大。这些研究结果表明,在美国,H1 a .1.1.3分支的检测增加不太可能直接归因于复制、传播或抗原漂移的改变,而可能是由于不同疫苗使用或先前暴露、生产实践的变化或生态条件导致的人群免疫力的变化。
{"title":"Pathogenesis and Transmission of a Reassorted H1 Influenza A Virus Detected in North American Swine.","authors":"Débora B Goulart, Carine K Souza, Giovana C Zanella, Celeste A Snyder, Janice C Zanella, Alexey Markin, Bailey Arruda, Tavis K Anderson, Amy L Baker","doi":"10.1111/irv.70228","DOIUrl":"https://doi.org/10.1111/irv.70228","url":null,"abstract":"<p><strong>Background: </strong>The USDA influenza A virus in swine national surveillance plan identified an increase in the detection frequency of a group of swine 1A.1.1.3 hemagglutinin (HA) clade viruses. This change was associated with reassortment events that resulted in new neuraminidase (NA) gene pairings. We hypothesized that the new N1 genes improved the transmission efficiency of the virus.</p><p><strong>Methods: </strong>We assessed the pathogenesis and transmission of four H1 1A.1.1.3 swine strains paired with different NA subtypes and lineages, all of which shared similar internal gene constellations.</p><p><strong>Results: </strong>There was little variation in the titers of viral nasal shedding across the groups, and the different surface protein pairings had no effect on transmission efficiency. All IAV strains, reflecting both pre- and post-reassortment genetic patterns, were transmitted to naïve indirect contact pigs.</p><p><strong>Conclusions: </strong>These data indicate that the combinations of 1A.1.1.3 HA with NA subtypes had little impact on transmission. These findings suggest that the increased detection of the H1 1A.1.1.3 clade in the United States was unlikely directly due to altered replication, transmission, or antigenic drift, but perhaps due to changes in population immunity resulting from differential vaccine use or prior exposure, variations in production practices, or ecological conditions.</p>","PeriodicalId":13544,"journal":{"name":"Influenza and Other Respiratory Viruses","volume":"20 2","pages":"e70228"},"PeriodicalIF":4.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146226623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Following WHO recommendations issued in 2019 and 2022, the National Influenza Center (NIC) of Côte d'Ivoire initiated the integration of Respiratory Syncytial Virus (RSV) and SARS-CoV-2 surveillance into its existing sentinel influenza surveillance to strengthen the monitoring of respiratory viruses.
Methods: The national influenza sentinel surveillance protocol was revised to include specific requirement of RSV and SARS-CoV-2. Nasopharyngeal swabs were collected between January 2022 and December 2023 for all three viruses and were tested by real time RT-PCR. Only PCR-positive samples with Ct value < 28 and adequate sample volume were selected for sequencing. CDC Flu SC2 multiplex rRT-PCR assay and Oxford Nanopore MinION Mk1C were used; influenza sequencing was performed at CDC Atlanta. Phylogenetic analyses were conducted to identify genotypes, lineages, and assess genetic relatedness to global strains.
Results: Between January 2022 and December 2023, 8316 samples were tested; 12.6% (n = 1044) were positive for at least one of the three viruses. RSV (5.63%) detection in severe acute respiratory infection (SARI) cases increased significantly from 3.4% in 2022 to 8.4% in 2023 (p < 0.0001). Similarly, influenza (3.71%) detection in SARI cases rose from 1.3% to 2.6% (p = 0.0057). SARS-CoV-2 (3.22%) detection was significantly associated with age (p = 0.002). All three viruses circulated year-round with distinct seasonal peaks. Genomic analysis showed that A(H3N2) viruses belonged to clade 3C.2a1b.2a.2, A(H1N1) pdm09 to clade 6B.1A.5a.2 and B/Victoria to clade V1A.3a.2, all aligning with global trends. Among SARS-CoV-2 cases, BA.2 and BA.5 sublineages of Omicron predominated in 2022 while XBB and XBB.1.5 sublineages emerged in 2023. Whole genome sequencing revealed RSV A strains as genotype A.D.5.1 and RSV B as genotype B.D.E.1.
Conclusion: Integration of RSV and SARS-CoV-2 into influenza sentinel surveillance has enabled continuous detection and genomic characterization, reinforcing the critical role of integrated sentinel surveillance for timely response to respiratory virus threats.
{"title":"Strengthening Respiratory Virus Surveillance in Sub-Saharan Africa: Integrated Epidemiological and Genomic Monitoring in Côte d'Ivoire.","authors":"Hervé A Kadjo, Daouda Coulibaly, Yakoura Karidja Ouattara, Sylla Aboubacar, Diané Maxime, Nguessan Konan, Kouakou Luc-Venance, Kouassi Helene, Mboua Jean Marc, Kouakou Bertin, Adagba Marius, Edgard Adjogoua, Ekra Daniel, Meite Syndou","doi":"10.1111/irv.70239","DOIUrl":"10.1111/irv.70239","url":null,"abstract":"<p><strong>Background: </strong>Following WHO recommendations issued in 2019 and 2022, the National Influenza Center (NIC) of Côte d'Ivoire initiated the integration of Respiratory Syncytial Virus (RSV) and SARS-CoV-2 surveillance into its existing sentinel influenza surveillance to strengthen the monitoring of respiratory viruses.</p><p><strong>Methods: </strong>The national influenza sentinel surveillance protocol was revised to include specific requirement of RSV and SARS-CoV-2. Nasopharyngeal swabs were collected between January 2022 and December 2023 for all three viruses and were tested by real time RT-PCR. Only PCR-positive samples with Ct value < 28 and adequate sample volume were selected for sequencing. CDC Flu SC2 multiplex rRT-PCR assay and Oxford Nanopore MinION Mk1C were used; influenza sequencing was performed at CDC Atlanta. Phylogenetic analyses were conducted to identify genotypes, lineages, and assess genetic relatedness to global strains.</p><p><strong>Results: </strong>Between January 2022 and December 2023, 8316 samples were tested; 12.6% (n = 1044) were positive for at least one of the three viruses. RSV (5.63%) detection in severe acute respiratory infection (SARI) cases increased significantly from 3.4% in 2022 to 8.4% in 2023 (p < 0.0001). Similarly, influenza (3.71%) detection in SARI cases rose from 1.3% to 2.6% (p = 0.0057). SARS-CoV-2 (3.22%) detection was significantly associated with age (p = 0.002). All three viruses circulated year-round with distinct seasonal peaks. Genomic analysis showed that A(H3N2) viruses belonged to clade 3C.2a1b.2a.2, A(H1N1) pdm09 to clade 6B.1A.5a.2 and B/Victoria to clade V1A.3a.2, all aligning with global trends. Among SARS-CoV-2 cases, BA.2 and BA.5 sublineages of Omicron predominated in 2022 while XBB and XBB.1.5 sublineages emerged in 2023. Whole genome sequencing revealed RSV A strains as genotype A.D.5.1 and RSV B as genotype B.D.E.1.</p><p><strong>Conclusion: </strong>Integration of RSV and SARS-CoV-2 into influenza sentinel surveillance has enabled continuous detection and genomic characterization, reinforcing the critical role of integrated sentinel surveillance for timely response to respiratory virus threats.</p>","PeriodicalId":13544,"journal":{"name":"Influenza and Other Respiratory Viruses","volume":"20 2","pages":"e70239"},"PeriodicalIF":4.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146213269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}