Skip to main content

Posts

Serologic #Surveillance for #Orthoflaviviruses and #Chikungunya Virus in #Bats and #Opossums in #Chiapas, #Mexico

Abstract We performed serologic surveillance for selected arthropod-borne viruses (arboviruses) in bats and opossums in the Lacandona Rainforest, Chiapas, Mexico , in 2023–2024. Sera were collected from 94 bats of at least 15 species and 43 opossums of three species. The sera were assayed by the plaque reduction neutralization test (PRNT) for antibodies to eight orthoflaviviruses ( dengue viruses 1–4, St. Louis encephalitis virus , T’Ho virus, West Nile virus, and Zika virus ) and one alphavirus (chikungunya virus; CHIKV). Twelve (12.8%) bats and 15 (34.9%) opossums contained orthoflavivirus-specific antibodies . One bat (a Jamaican fruit bat) was seropositive for Zika virus , and 11 bats contained antibodies to an undetermined orthoflavivirus , as did the 15 opossums. All bats and most opossums seropositive for an undetermined orthoflavivirus had low PRNT titers, possibly because they had been infected with another (perhaps unrecognized) orthoflavivirus not included in the PRNTs. Anti...

#Lassa Virus #Infection of Primary #Human #Airway Epithelial Cells

Abstract Lassa mammarenavirus (LASV), a member of the family Arenaviridae , is a highly pathogenic virus capable of causing severe systemic infections in humans . The primary host reservoir is the Natal multimammate mouse (Mastomys natalensis), with human infections typically occurring through mucosal exposure to virus-containing aerosols from rodent excretions . To better understand the molecular mechanisms underlying LASV replication in the respiratory tract, we utilized differentiated primary human airway epithelial cells (HAECs) grown under air–liquid interface conditions, closely mimicking the bronchial epithelium in vivo. Our findings demonstrate that HAECs are permissive to LASV infection and support productive virus replication . While LASV entry into polarized HAECs occurred through both apical and basolateral surfaces , progeny virus particles were predominantly released from the apical surface , consistent with an intrinsic apical localization of the envelope glycoprotein GP...

#Vietnam reported one additional #human #infection with avian #influenza virus A #H5N1 (HK CHP, April 22 '25)

Influenza A H5N1, New Cases reported, week 16/2025 : - Date: 18/04/2025; - Country: Vietnam;  - Province: Tay Ninh province, Ben Cau district;  - Sex: Female; - Age: 8;  - Clinical condition: Serious; - Subtype: H5N1. (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk16.pdf ____

Molecular and ecological #determinants of #mammalian #adaptability in avian #influenza virus

Abstract The avian influenza virus (AIV) primarily affects birds and poses an increasing concern due to its growing adaptability to other hosts , heightening zoonotic risks . The adaptability is a key factor in AIV to infect multiple non-avian species, including humans , companion animals , aquatic mammals , carnivores , and other mammals. The virus is evolving through genetic mutations and reassortments , leading to the emergence of AIV strains with enhanced virulence and adaptability in mammals. This highlights the critical need to understand the genetic factors of AIV, including mutations in polymerase proteins , surface antigens , and other regulatory proteins, as well as the dynamics of AIV- host interactions and environmental factors such as temperature, humidity, water salinity, and pH that govern the cross-species adaptability of the virus. This review provides comprehensive insights into the molecular/genetic changes AIV undergoes to adapt in mammalian hosts including bovines,...

Exploring influenza A virus receptor distribution in the lactating mammary gland of domesticated livestock and in human breast tissue.

Abstract The spread of the highly pathogenic avian influenza (HPAI) H5N1 virus among dairy cattle illustrates the adaptability of influenza A viruses (IAV) to infect non-traditional species . While IAV-specific sialic acid (SA) receptors have been identified in the mammary glands of dairy cattle , their presence in pigs, sheep, goats, and alpacas has not been studied until now. The zoonotic transmission of HPAI H5N1 to dairy and poultry farm workers during outbreaks raises public health concerns . This study employed lectin histochemistry to examine the mammary glands of livestock and humans . We found that these tissues were rich in SA α2,6-Gal receptors, followed by SA α2,3-Gal receptors , essential for IAV binding . Notably, the A(H5N1) clade 2.3.4.4b virus could bind to mammary tissue from both cattle and pigs . These findings highlight the potential for HPAI H5N1 to infect and spread within the mammary glands of production animals and humans. Source: BioRxIV,  https://www.bior...

#Wastewater #sequencing reveals the #genomic landscape of #Influenza A virus in #Switzerland

Abstract Influenza A virus poses significant public health challenges , causing seasonal outbreaks and pandemics. Its rapid evolution motivates continuous monitoring of circulating influenza genomes to inform vaccine and antiviral development. Wastewater-based surveillance offers an unbiased, cost-effective approach for genomic surveillance. We developed a novel tiling amplicon primer panel that covers diversity of influenza A virus, targeting segments of the surface proteins HA, NA, and M of subtypes H1N1 and H3N2. Using this panel, we sequenced nucleic acid extracts from 59 Swiss wastewater samples collected at four locations during the 2022/2023 and 2023/2024 winter seasons. We found that wastewater-based abundance estimates of the dominant H1N1 clades correlated with clinical-based estimates in the 2023/2024 season. Furthermore, wastewater-based sequencing revealed mutations in vaccine and drug target sites , consistent with clinical data. Overall, we demonstrate the effectiveness ...

Impacts of high pathogenicity avian #influenza #H5N1 2.3.4.4b south of the #Antarctic Circle

Abstract High pathogenicity avian influenza (HPAI) H5N1 2.3.4.4b poses a substantial conservation threat to ecosystems , populations, and species globally, with its continued spread into new regions increasing concern for potential ecological consequences . During surveys in February-March 2025, we confirmed the virus presence at the southern extent of its known range along the Western Antarctic Peninsula, with recorded mortalities in South Polar Skuas Stercorarius maccormicki on distinct islands in Marguerite Bay , as well as one confirmed and one suspected case in Kelp Gulls Larus dominicanus . At the time of sampling, no evidence of infection was observed in other seabird or mammal species. Consistent with previous global reports, skuas - here, South Polar Skuas - appear particularly vulnerable, yet broader impacts on the local seabird and mammal community remain unclear. Additionally, our use of rapid antigen tests (VDRG AIV Ag Rapid kit 2.0 Median Diagnostics) in the field demonst...

Insights into the #clinical and molecular #epidemiology of an infections #outbreak of human #parvovirus B19 in #France, 2023-2024

Highlights •  A large B19V French outbreak of an unexpected magnitude occurred, with a monthly rate that has reached 21.4%. •  During this outbreak, 50% of infected pregnant women exhibited fetal complications. •  Phylogenetic analysis revealed the co-circulation of several B19V lineages of genotype 1a, the main epidemic lineage of which emerged in 2017. Abstract Background The human parvovirus B19 (B19V) infections cycle occurs in 3- to 4-year periods and is responsible for benign childhood erythema infectiosum . It is also associated with transient aplastic crisis in patients with underlying hemolytic diseases and with severe fetal sometimes fatal infection . This study investigated the epidemiological, clinical and molecular characteristics of an unusually large 2023-2024 outbreak of B19V. Methods . Laboratory-confirmed cases were retrospectively and prospectively recorded at the Clermont-Ferrand University Hospital, France , between January, 2018 and November, 2023 an...

#Coronavirus Disease Research #References (by AMEDEO, April 19 '25)

  Am J Respir Crit Care Med BALTE PP, Kim JS, Sun Y, Allen N, et al Associations of Pre-Pandemic Lung Function and Structure with COVID-19 Outcomes: The C4R Study. Am J Respir Crit Care Med. 2025 Apr 16. doi: 10.1164/rccm.202408-1656. PubMed           Abstract available Antiviral Res KELLY JA, Aida-Ficken V, McMullan LK, Chatterjee P, et al Mechanisms of action of repurposed Ebola virus antivirals - the roles of phospholipidosis and cholesterol homeostasis. Antiviral Res. 2025 Apr 15:106167. doi: 10.1016/j.antiviral.2025.106167. PubMed           Abstract available Clin Infect Dis MESSCHENDORP AL, Zaeck LM, Bouwmans P, van den Broek DAJ, et al Replacing Mycophenolate Mofetil by Everolimus in Kidney Transplant Recipients to Increase Vaccine Immunogenicity: Results of a Randomized Controlled Trial. Clin Infect Dis. 2025 Apr 15:ciaf107. doi: 10.1093. PubMed           ...

#Influenza and Other Respiratory Viruses Research #References (by AMEDEO, April 19 '25)

  Am J Med BILC M, Cramer H Use of Complementary Medicine Among US Adults with Post-COVID-19: Results from the 2022 National Health Interview Survey. Am J Med. 2025;138:862-869. PubMed           Abstract available MAURO M, Cegolon L, Bestiaco N, Zulian E, et al Heart Rate Variability Modulation Through Slow-Paced Breathing in Health Care Workers with Long COVID: A Case-Control Study. Am J Med. 2025;138:870-883. PubMed           Abstract available NAIK H, Wilton J, Tran KC, Janjua NZ, et al Long-Term Health-Related Quality of Life in Working-Age COVID-19 Survivors: A Cross-Sectional Study. Am J Med. 2025;138:850-861. PubMed           Abstract available PALACIO A, Bast E, Klimas N, Tamariz L, et al Lessons Learned in Implementing a Multidisciplinary Long COVID Clinic. Am J Med. 2025;138:843-849. PubMed           Abstract avail...

Emerging #zoonotic potential of #H4N1 avian #influenza virus: enhanced #human #receptor binding and #replication via novel mutations

Abstract Background Avian influenza virus (AIV), a zoonotic pathogen found worldwide , includes multiple subtypes, one of which is the H4 subtype frequently detected in wild birds and poultry . Despite its prevalence, research on H4 subtype AIV has been scarce, with a focus predominantly on the H4N2 and H4N6 subtypes. The zoonotic potential of H4N1 has not been investigated to date. Methods In this study, we used gene sequencing in conjunction with bioinformatics methodologies to analyze wild-type H4N1 AIV strain and mutant strains emerging from serial passaging in cell culture . Furthermore, we assessed the zoonotic potential of H4N1 and the alterations caused by mutations via a series of phenotype assays, including evaluation of receptor binding affinity, immunofluorescence assays, analyses of growth kinetics across different animal cell cultures, and in vivo pathogenicity studies. Results Our research reveals that H4N1 AIV can bind to human receptors and exhibits an affinity for hum...

Sustained cross-species #transmission of #gammacoronavirus in wild #birds reveled by viral characterization in #China

Abstract Gammacoronavirus (γ-CoV) primarily infects poultry, wild birds, and marine mammals . The widespread distribution and circulation of γ-CoV in the ecological environment may lead to sustained transmission and economic loss . To better understand the diversity of γ-CoV in wild birds , we collect 482 wild-bird fecal samples from Yunnan , encompassing fourteen bird species . We detected twelve γ-CoV positive samples in five bird species, with the characterization of five complete genomes - HNU5-1, HNU5-2, HNU5-3, HNU6-1, and HNU6-2 -indicating that these genomes represent two viral species . The HNU5 strains were derived from Black-headed gull (Chroicocephalus ridibundus), while the HNU6 strains were came from Mallard (Anas platyrhynchos), and both of those were recombinant. The HNU5 strain exhibited the highest sequence identity (95.45%) with a γ-CoV strain isolated from Numenius phaeopus (GenBank accession: PP845452). Similarly, the HNU6 strain showed 95.18% nucleotide identity w...

Detection of Avian #Influenza Virus in #Pigeons

Abstract Pigeons (Columba livia) are usually kept as free-ranging or racing birds, and they have direct contact with livestock, poultry, and humans . Therefore, they may have an important role in the ecology of influenza virus among various species. In the present study, we bring together all available sequence data of pigeon avian influenza virus (AIV) from public databases to address the current understanding of the genomic characteristics and emergence of each subtype of AIV in pigeons. Collectively, we identified 658 pigeon AIV strains in 21 countries across the world, which were mainly distributed in Europe, Asia, and North America. H1 (2), H2 (1), H3 (8), H5 (71), H6 (16), H7 (16), H9 (543), and H11 (1) AIV subtypes have been identified in pigeons. In addition, we interrogate features of the H5, H6, H7, and H9 subtypes of pigeon AIV, which are relatively common in pigeons. It is particularly noteworthy that the H5 AIV strains identified in pigeons are all classified as HPAIV. For...

#Liberia - High pathogenicity avian #influenza #H5N1 viruses (poultry) (Inf. with) - Immediate notification

  A poultry farm in Totota, right behind the Lutheran football field in Bong County. Source: WOAH,  https://wahis.woah.org/#/in-review/6432 ____

#USA, Monitoring for Avian #Influenza A(#H5) Virus In #Wastewater (as of April 18 '25)

{Excerpt} Time Period: April 06, 2025 - April 12, 2025 -- H5 Detection :  3 sites ( 0.9% ) -- No Detection :  348 sites ( 99.1% ) -- No samples in last week :  243 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html?cove-tab=0 ____

#Chikungunya virus virus-like particle #vaccine #safety and immunogenicity in adults older than 65 years: a phase 3, randomised, double-blind, placebo-controlled trial

Summary Background Adults older than 65 years are at increased risk for atypical presentations of chikungunya disease, as well as for severe outcomes including death. Methods In this phase 3, randomised, double-blind, placebo-controlled, parallel-group trial, adults aged 65 years and older received a single intramuscular dose of Vimkunya (previously chikungunya virus virus-like particle vaccine) or placebo at ten sites in the USA. Participants, clinical site personnel, and the sponsor were masked to individual treatment assignments until all participants had completed their involvement in the trial and the database was cleaned and locked. Baseline and postvaccination chikungunya virus serum neutralising antibody (SNA) titres (NT80) were assessed at selected timepoints. Safety was assessed up to 183 days after dose administration in all participants from the exposed population who provided safety assessment data. This trial is registered with ClinicalTrials.gov, NCT05349617, and is comp...

Estimates of #epidemiological #parameters for #H5N1 #influenza in #humans: a rapid review

Abstract Background   The ongoing H5N1 panzootic in mammals has amplified zoonotic pathways to facilitate human infection . Characterising key epidemiological parameters for H5N1 is critical should it become widespread.  Aim   To identify and estimate critical epidemiological parameters for H5N1 from past and current outbreaks, and to compare their characteristics with human influenza subtypes and the 2003 Netherlands H7N7 outbreak .  Methods   We searched PubMed, Embase, and Cochrane Library for systematic reviews reporting parameter estimates from primary data or meta-analyses. To address gaps, we searched PubMed and Google Scholar for studies of any design providing relevant estimates. We estimated the basic reproduction number for the outbreak in the US and the 2003 Netherlands H7N7 outbreak. In addition we estimated the serial interval for H5N1 using data from previous household clusters in Indonesia . We also applied a branching process model to simulate t...

Towards #diagnostic #preparedness: detection of #HPAI A(#H5N1) in contrived nasal #swab #specimens using rapid #antigen and point-of-care molecular tests

Abstract Highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b was first detected in birds in the United States in 2021 and an ongoing outbreak in dairy cattle began in early 2024. At least 70 U.S. cases have been identified in humans with exposure to infected cattle, poultry, and wild birds. No human-to-human transmission has been documented . However, as part of diagnostic preparedness, we evaluated the ability of currently available influenza tests to detect 2024 U.S. H5N1 strains. Contrived nasal swab samples were prepared using live or inactivated 2024 H5N1 and used to test twelve rapid antigen tests (lateral flow assays, or LFA), including 10 commercially-available influenza A LFAs and two H5-specific LFAs. Five point-of-care (POC) molecular assays were also tested. An inclusivity testing protocol was used, wherein a predetermined dilution series is used to evaluate each assay, enabling head-to-head comparison of assay performance. All lateral flow assays and POC molecu...

Updated joint #FAO / #WHO / #WOAH public health #assessment of recent #influenza A(#H5) virus events in #animals and people - Assessment based on data as of 1 March 2025

Key points   -- At the present time , based on available information, FAO-WHO-WOAH assess the global public health risk of influenza A(H5) viruses to be low , while the risk of infection for occupationally exposed persons is low to moderate depending on the risk mitigation measures in place and the local avian influenza epidemiological situation.  -- Transmission between animals continues to occur and, to date, a growing yet still limited number of human infections are being reported. Although additional human infections associated with exposure to infected animals or contaminated environments are expected to occur, the overall public health impact of such infections at a global level, at the present time, is considered minor .  -- The assessment could change if and when additional epidemiological or virological information becomes available.  -- This risk assessment from FAO, WHO and WOAH updates the assessment of the risk of zoonotic transmission (for example, ani...