Detection Of Influenza Virus Research Articles

Ultrasensitive point-of-care multiplex diagnosis for influenza virus based robust quantum dot microsphere-lateral flow immunoassay.

Influenza A virus (IAV) and influenza B virus (IBV) with similar symptoms of infection caused a serious disease burden and economic losses in annual epidemic season, so it is important to quickly and accurately detect and distinguish between IAV and IBV during influenza season. Herein, the quantum dot microspheres (QDMS) were synthesized and applied to lateral flow immunoassays (LFIA), and a point-of-care (POC) biosensor that can discriminately and simultaneously diagnose IAV and IBV within 10min was established. A double-sandwich QDMS nanotags was synthesized by immobilizing hydrophobic quantum dots (QDs) with chemical bonding method on a silica sphere template with an outer silica shell protection showed excellent stability and high fluorescence. The highly sensitive quantitative detection is achieved with the tailored hand-hold detector. The limit of detection (LOD) of the LFIA based QDMS for the simultaneous detection of IAV and IBV were 0.080ng/mL and 0.096ng/mL, respectively. The QDMS-LFIA system has excellent specificity and stability for quantitative detection, especially showing good accuracy for clinical samples. Furthermore, the visualization sensitivity of the low-cost biosensor was improved by nearly an order of magnitude than gold nanoparticles (AuNP)-LFIA within shorter detection time. Given the excellent performance, our proposed QDMS-LFIA biosensor can potentially be applied to the POC sensitive discriminate and simultaneous detection of IAV and IBV in epidemic season.

Rapid and specific on-site H5Nx avian influenza diagnosis via RPA and PAM-independent CRISPR-Cas12a assay combined with anti-NP antibody-based viral RNA purification

Rapid and accurate detection of H5Nx avian influenza viruses is critical for effective surveillance and control measures. Currently, RT-qPCR with spin column RNA extraction is the gold standard for HPAIV surveillance, but its long reaction time and need for specialized equipment limit its effectiveness for rapid response. In this study, we introduce a centrifuge-free, rapid detection method for on-site detection of H5Nx viruses that combines magnetic bead-based ribonucleoprotein (RNP) purification and concentration with a CRISPR-Cas12a system that is independent of the protospacer adjacent motif (PAM) sequence. Our approach employs anti-NP monoclonal antibodies for the targeted isolation of RNA bound to RNPs, facilitating a quick and specific RNA extraction process that negates the need for centrifugation. Additionally, by denaturing the RT-RPA amplicon using 60% DMSO, we activate the trans-ssDNA cleavage activity of the Cas12a protein without the need for a specific PAM (5’-TTTV-3′) sequence. This strategy increases flexibility in CRISPR RNA design, providing a significant advantage when targeting genes with high variability. We validated the efficacy of our magnetic RNP purification and concentration method in combined with an RT-RPA/PAM-independent Cas12a assay for detecting the H5 gene. The assay achieved a sensitivity threshold of 101 EID50 with fluorescent detection and 102 EID50 using lateral flow strips. It also exhibited high specificity, yielding positive results solely for H5Nx viruses among various influenza A virus subtypes. Furthermore, in clinical samples, the assay demonstrated 80% sensitivity and 100% specificity. These results highlight the advantages of using NP-specific antibodies for RNP purification and CRISPR-Cas12a with viral gene-specific crRNA to achieve exceptional diagnostic specificity.

Self-service aptamer-free molecularly imprinted paper-based sensor for high-sensitivity visual detection of influenza H5N1.

Developing low-cost self-service portable sensors to detect viruses is an important step in combating the spread of viral outbreaks. Here, we describe the development of an aptamer-free paper-based molecularly imprinted sensor for the instrument-free detection of influenza virus A (H5N1). In this sensor, Whatman paper loaded with Fe3O4 nanoparticles (WP@Fe3O4) was prepared as a substrate upon which silicon imprinting occurred in the presence of the template virus H5N1. After removal of the template virus, Fe3O4 which exposed in the imprinted cavities was able to catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide to form blue TMB + ions. Therefore, the concentration of virus can be semi-quantified by the color change of the solution after the catalytic reaction in the absence of any instruments. The color reaction can be clearly observed within 20 min. In addition, the remaining TMB could be quantified fluorometrically, with a limit of detection of 1.16 fM and an imprinting factor of 4.7. As far as we know, this sensor detects the target with the highest sensitivity that has yet been achieved in aptamer-free molecular imprinting sensors. Importantly, the cost of materials used for each sensor was as low as 4 cents (0.23 Yuan) per sensor. This sensitive self-service sensor, which is relatively easy and inexpensive to produce, will provide an effective new avenue for the rapid detection of viruses.

Avian influenza overview September-December 2024.

Between 21 September and 6 December 2024, 657 highly pathogenic avian influenza (HPAI) A(H5N1) and A(H5N5) virus detections were reported in domestic (341) and wild (316) birds across 27 countries in Europe. Many HPAI outbreaks in domestic birds were clustered in areas with high poultry density and characterised by secondary farm-to-farm spread. Waterfowl, particularly the mute swan, were primarily affected during this reporting period, with HPAI virus detections focused on south-eastern Europe. Notably, A(H5N5) viruses expanded their geographic and host range, resulting in a surge in detections and mortality events described in gulls and crows. No new HPAI virus detections in mammals were reported in Europe during this reporting period, but the number of dairy cattle farms reportedly affected in the United States of America (USA) rose to >800 in 16 States, and HPAI virus was identified in two pigs in a mixed-species farm. Between 21 September and 11 December 2024, 56 new human cases with avian influenza virus infection were reported from North America (45 A(H5N1) cases), Viet Nam (one A(H5)) and China (ten A(H9N2) cases). Most of the A(H5) human cases in North America (95.6%, n = 43/45) had reported exposure to poultry, live poultry markets, or dairy cattle prior to avian influenza virus detection or onset of illness. Human infections with avian influenza viruses remain rare and no evidence of human-to-human transmission has been documented in the reporting period. The risk of infection with currently circulating avian A(H5) influenza viruses of clade 2.3.4.4b in Europe remains low for the general public in the European Union/European Economic Area (EU/EEA). The risk of infection remains low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.

One-Step Immunoassay for the Detection of Influenza Virus Based on Screened Nucleoprotein (NP)-like Mimotopes from Fv-Antibody Library

One-Step Immunoassay for the Detection of Influenza Virus Based on Screened Nucleoprotein (NP)-like Mimotopes from Fv-Antibody Library

Antigenic changes in influenza A(H3N2) driven by genetic evolution: Insights from virological surveillance, EU/EEA, week 40/2023 to week 9/2024.

BackgroundDuring the 2023/24 influenza season in the European Union/European Economic Area (EU/EEA), influenza viruses A(H1N1)pdm09, A(H3N2) and B/Victoria viruses were co-circulating.AimWe aimed to describe the circulating influenza viruses by (sub)type, genetic clade, antigenic group and antiviral susceptibility in that season in the EU/EEA.MethodsWe collected surveillance data from EU/EEA countries through weekly submissions to The European Surveillance System (TESSy). Data were submitted in strain-based format for weeks 40/2023 to 9/2024.ResultsTwenty-nine EU/EEA countries reported 154,718 influenza virus detections (primary care sentinel and non-sentinel combined), of which 97% (150,692) were type A and 3% (4,026) were type B. Of the subtyped influenza A viruses, 30,463 (75%) were influenza A(H1)pdm09 and 10,174 (25%) were influenza A(H3). For 809 (20%) of the type B viruses, the lineage was determined; all were B/Victoria/2/87 lineage, and none were B/Yamagata/16/88 lineage. Genetic diversification of seasonal influenza viruses continued, and clade 5a.2a of A(H1N1)pdm09, 2a.3a.1 of A(H3N2) and V1A.3a.2 of B/Victoria-lineage viruses dominated. Of the A(H3N2) 2a.3a.1 viruses, 23% were antigenically distinct from the 2023/24 vaccine virus.ConclusionThe 2023/24 influenza season was characterised by co-circulation of different influenza (sub)types, antigenically similar to the components recommended for the 2023/24 northern hemisphere vaccine, A/Victoria/4897/2022 (egg-based) and A/Wisconsin/67/2022 (cell culture- or recombinant-based). However, genetic diversification of the viruses continued. The World Health Organization's vaccine recommendations for the northern hemisphere 2024/25 season were updated to include a new A(H3N2) component, while maintaining the current A(H1N1)pdm09 and B/Victoria components.

High sensitivity detection of influenza virus using polymer-coated microcavity biosensor

Influenza viruses are a major global public health concern because they cause seasonal epidemics and sporadic pandemics. The sensitivity and specificity of viral detection can be improved through recent developments in biosensor technology. The capacity of microcavity biosensors to detect biomolecules, including viruses, in real-time without requiring labels caused interest among them. In this study, we present a novel polymer-coated microcavity biosensor for the high-sensitivity detection of the H1N1 influenza virus. The main microcavity structure of this label-free biosensor is intended to improve sensitivity by optimizing performance characteristics specific to viral samples. The simulation indicates the microcavity resonator’s outstanding sensitivity in H1N1. Our biosensor efficiently detects H1N1 at lower concentrations than conventional diagnostic techniques by utilizing a polymer coating that improves binding affinity and encourages the immobilization of certain antibodies. Using the polymer layer enhances the sensor’s functionality and confers biocompatibility, opening up possible uses in point-of-care environments. The polymer-coated microcavity biosensor, according to our research, is a potential platform for early, sensitive, and quick influenza virus detection, greatly assisting with public health response and monitoring activities.

A novel cascade colorimetric biosensor based on three-way junction-initiated primer exchange reaction for detection of influenza virus

A novel biosensor based on a three-way junction (3WJ)-induced primer exchange reaction was developed for detection of the H1N1 virus. The target H1N1 RNA induced formation of a 3WJ. The subsequent assembly of two DNA probes triggered amplification of downstream strand displacement to copiously generate signal primers to initiate primer exchange reaction to form a long single-stranded sequence containing multiple G quadruplet repeats. Abundant G-quadruplex/hemin was formed in the presence of hemin, thus catalyzing a colorimetric reaction. The detection limit of the colorimetric biosensor was 34.32 fM with a linear relationship from 100 pM to 1 μM. By simply changing the sequence of the two probes based on the target-specific sequence, the biosensor can be easily extended to detect other viral RNA. The proposed biosensor successfully detected H1N1 RNA as a sensitive, portable, and cost-effective alternative to current methods.

Application of surface Plasmon resonance imaging in the high-throughput detection of influenza virus.

To evaluate the application effect of SPRi monoclonal antibody (mAb) chip in the detection of influenza virus antigen in complex mixtures. A total of 115 strains of mAbs against different subtypes (H1N1, H5N1, A1, A3, B, H7N9, H9N2, and H3N2) of influenza virus were prepared. The chip of mAbs against influenza virus was prepared by surface plasmonic resonance imaging (SPRi) technology, which was used for the detection of influenza virus supernatant, and compared with the traditional antigen capture ELISA method. Comparative studies have shown that traditional antigen capture ELISA methods have a higher sensitivity (86.8% (46/53) vs. 46.5% (46/99); z = 4.84, P < .001), while the SPRi chip methods present a significantly higher specificity (56.3% (9/16) vs. 14.5% (9/62); z = 3.54, P < .001). The SPRi chip detection method for influenza virus antibodies can well reflect the specific binding characteristics of influenza virus antigens and antibodies. The SPRi mAb chip can be used for the detection of specific pathogenic microorganisms or viral proteins in complex mixtures such as influenza virus supernatant. It has significant advantages of label free, real-time, high-throughput, and good specificity, and can play an important role in disease diagnosis and infectious disease prevention and control.

Research progress on environmental stability of SARS-CoV-2 and influenza viruses.

We reviewed research on SARS-CoV-2 and influenza virus detection on surfaces, their persistence under various conditions, and response to disinfectants. Viral contamination in community and healthcare settings was analyzed, emphasizing survival on surfaces influenced by temperature, pH, and material. Findings showed higher concentrations enhance survivability at room temperature, whereas stability increases at 4°C. Both viruses decline in low pH and high heat, with influenza affected by salinity. On various material surfaces, SARS-CoV-2 and influenza viruses demonstrate considerable variations in survival durations, and SARS-CoV-2 is more stable than influenza virus. On the skin, both virus types can persist for ≥2 h. Next, we delineated the virucidal efficacy of disinfectants against SARS-CoV-2 and influenza viruses. In daily life, exposure to ethanol (70%), isopropanol (70%), bleach (10%), or hydrogen peroxide (1-3%) for 15-30 min can effectively inactive various SARS-CoV-2 variants. Povidone-iodine (1 mg/mL, 1 min) or cetylpyridinium chloride (0.1 mg/mL, 2 min) may be used to inactive different SARS-CoV-2 variants in the mouth. Chlorine disinfectants (500 mg/L) or ultraviolet light (222 nm) can effectively inhibit different SARS-CoV-2 variants in public spaces. In conclusion, our study provides a scientific basis and practical guidance for reduction of viral persistence (retention of infectivity) on surfaces and environmental cleanliness.

Avian influenza overview June-September 2024.

Between 15 June and 20 September 2024, 75 highly pathogenic avian influenza (HPAI) A(H5) and A(H7) virus detections were reported in domestic (16) and wild (59) birds across 11 countries in Europe. Although the overall number of detections in Europe continued to be low compared to previous epidemiological years, an increase in cases along the Atlantic, North Sea and Baltic coasts was notable, particularly an increase in the detection of HPAI viruses in colony-breeding seabirds. Besides EA-2022-BB and other circulating genotypes, these detections also included EA-2023-DT, a new genotype that may transmit more efficiently among gulls. In Germany, HPAI A(H7N5) virus emerged in a poultry establishment near the border with the Netherlands. No new HPAI virus detections in mammals were reported in Europe during this period, but the number of reportedly affected dairy cattle establishments in the United States of America (USA) rose to >230 in 14 states, and HPAI virus was identified in three new mammal species. Between 21 June and 20 September 2024, 19 new human cases with avian influenza virus infection were reported from the USA (six A(H5N1) cases and five A(H5) cases), Cambodia (five A(H5N1) cases, including one fatal), China (one fatal A(H5N6) case and one A(H9N2) case), and Ghana (one A(H9N2) case). Most of the human cases (90%, n = 17/19) had reported exposure to poultry, live poultry markets, or dairy cattle prior to avian influenza virus detection or onset of illness. Human infections with avian influenza viruses remain rare and no evidence of human-to-human transmission has been documented in the reporting period. The risk of infection with currently circulating avian A(H5) influenza viruses of clade 2.3.4.4b in Europe remains low for the general public in the European Union/European Economic Area (EU/EEA). The risk of infection remains low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.

Highly-Efficient Selection of Aptamers for Quantitative Fluorescence Detecting Multiple IAV Subtypes.

Influenza A virus (IAV) can cause infectious respiratory diseases in humans and animals. IAVs mutate rapidly through antigenic drift and shift, resulting in the emergence of numerous IAV subtypes and significant challenges for IAV detection. Therefore, achieving the simultaneous detection of multiple IAVs is crucial. In this work, three specific aptamers targeting the hemagglutination (HA) protein of the influenza A H5N1, H7N9, and H9N2 viruses were screened using a multichannel magnetic microfluidic chip. The aptamers exhibit nanomolar affinity and excellent specificity for the HA protein of H5N1, H7N9, and H9N2 viruses. Furthermore, three specific aptamers were truncated and labeled with different fluorescence markers to realize fluorescence quantitative detection of influenza A H5N1, H7N9, and H9N2 viruses through an aptamer sandwich assay in 1 h. The limit of detection (LOD) of the developed method is 0.38 TCID50/mL for the H5N1 virus, 0.75 TCID50/mL for the H7N9 virus, and 1.14 TCID50/mL for the H9N2 virus. The detection method has excellent specificity, strong anti-interference ability, and good reproducibility. This work provides a sensitive quantitative detection method for the H5N1, H7N9, and H9N2 viruses, enabling quantitative fluorescence detection for multiple IAV subtypes.

Flu seasons during the period 2018-2023 in Sarajevo Canton, Bosnia and Herzegovina: possible impact of the SARS-CoV-2 pandemic on the influenza A and B virus circulation.

During the pandemic of severe acute respiratory syndrome corona-virus 2 (SARS-CoV-2), many countries reported a significant decrease in the prevalence of influenza virus cases. The study aimed to characterize the flu seasons from 2018 to 2023 in Sarajevo Canton, Bosnia and Herzegovina (B&H), and to assess the possible impact of the SARS-CoV-2 pandemic on the influenza A and B virus circulation. The CDC Human Influenza Virus Real-Time RT-PCR Diagnostic Panels were used for the detection of influenza virus A and B, and subtyping of influenza virus A (H1pdm09 virus and H3). The data for this registry-based retrospective study were collected at the Clinical Centre of the University of Sarajevo, Unit for Clinical Microbiology (the laboratory that acts as a referral for the detection and characterization of influenza virus and SARS-CoV-2 in Federation B&H). In the 2018/2019 and 2019/2020, an equal percentage of positive cases was recorded (148/410; 36%, and 182/504; 36%, respectively). The absence of the influenza virus was observed in 2020/2021. During 2021/2022, influenza virus was detected among 19/104 (18%) patients and slightly increased in 2022/2023 (45/269; 17%). The switch of the influenza B virus lineage was observed. The SARS-CoV-2 virus had an impact on the prevalence of influenza virus infection among the population of the Sarajevo Canton, B&H. Since the interactions between these two viruses are not entirely clear, awareness of a possible threat to public health is crucial.

Co-circulation of seasonal influenza A(H1N1)pdm09, A(H3N2) and B/Victoria lineage viruses with further genetic diversification, EU/EEA, 2022/23 influenza season.

BackgroundInfluenza viruses can cause large seasonal epidemics with high healthcare impact and severity as they continually change their virological properties such as genetic makeup over time.AimWe aimed to monitor the characteristics of circulating influenza viruses over the 2022/23 influenza season in the EU/EEA countries. In addition, we wanted to compare how closely the circulating viruses resemble the viral components selected for seasonal influenza vaccines, and whether the circulating viruses had acquired resistance to commonly used antiviral drugs.MethodsWe performed a descriptive analysis of the influenza virus detections and characterisations reported by National Influenza Centres (NIC) from the 30 EU/EEA countries from week 40/2022 to week 39/2023 to The European Surveillance System (TESSy) as part of the Global Influenza Surveillance and Response System (GISRS).ResultsIn the EU/EEA countries, the 2022/23 influenza season was characterised by co-circulation of A(H1N1)pdm09, A(H3N2) and B/Victoria-lineage viruses. The genetic evolution of these viruses continued and clade 6B.1A.5a.2a of A(H1N1)pdm09, 3C.2a1b.2a.2b of A(H3N2) and V1A.3a.2 of B/Victoria viruses dominated. Influenza B/Yamagata-lineage viruses were not reported.DiscussionThe World Health Organization (WHO) vaccine composition recommendation for the northern hemisphere 2023/24 season reflects the European virus evolution, with a change of the A(H1N1)pdm09 component, while keeping the A(H3N2) and B/Victoria-lineage components unchanged.

Determination of airborne influenza virus and coronavirus infectivity using capsid integrity polymerase chain reaction

Accurate airborne virus monitoring is important for preventing the spread of infectious diseases. Although standard reverse transcription-quantitative polymerase chain reaction (RT-qPCR) can efficiently detect viral ribonucleic acid (RNA), it cannot determine whether the RNA is associated with active (infectious) or inactive (non-infectious) viruses. Plaque assay is the gold standard for determining viral infectivity but is laborious and time-consuming. This study explored the viral infectivity of H1N1 influenza virus and human coronavirus (HCoV-229E) using capsid integrity RT-qPCR, where virus samples were pretreated with reagents penetrating viruses with damaged capsids, impeding amplification by binding to their RNA. Therefore, the amplified signals corresponded solely to active viruses with undamaged capsids. Propidium monoazide (PMA) and platinum (IV) chloride (PtCl4) were used to investigate the effects of reagent concentration. Feasibility tests revealed that PtCl4 was more efficient than PMA, with optimal concentrations of 125–250 μM and 250–500 μM for H1N1 influenza virus and HCoV-229E, respectively. The results of percentage of active virus showed that capsid integrity RT-qPCR provided a trend similar to that of plaque assay, indicating an accurate measure of viral infectivity. Virus sampling in the laboratory and field highlighted the precision of this methodology for determining viral infectivity. Therefore, this methodology enables rapid and accurate detection of infectious airborne H1N1 influenza virus and HCoV-229E, allowing swift response to outbreaks.

An Fe3O4-Au heterodimer nanoparticle-based lateral flow assay for rapid and simultaneous detection of multiple influenza virus nucleic acids.

Sensitive, convenient and rapid detection and subtyping of influenza viruses are crucial for timely treatment and management of infected people. Compared with antigen detection, nucleic acid detection has higher specificity and can shorten the detection window. Hence, in this work, we improved the lateral flow assay (LFA, one of the most promising user-friendly and on-site methods) to achieve detection and subtyping of H1N1, H3N2 and H9N2 influenza virus nucleic acids. Firstly, the antigen-antibody recognition mode was transformed into a nucleic acid hybridization reaction. Secondly, Fe3O4-Au heterodimer nanoparticles were prepared to replace frequently used Au nanoparticles to obtain better coloration. Thirdly, four lines were arranged on the LFA strip, which were three test (T) lines and one control (C) line. Three T lines were respectively sprayed by the DNA sequences complementary to one end of H1N1, H3N2 and H9N2 influenza virus nucleic acids, while Fe3O4-Au nanoparticles were respectively coupled with the DNA sequences complementary to the other end of H1N1, H3N2 and H9N2 nucleic acids to construct three kinds of probes. The C line was sprayed by the complementary sequences to the DNAs on all three kinds of probes. In the detection, by hybridization reaction, the probes were combined with their target nucleic acids which were captured by the corresponding T lines to form color bands. Finally, according to the position of the color bands and their grey intensity, simultaneous qualitative and semi-quantitative detection of the three influenza virus nucleic acids was realized. The detection results showed that this multi-channel LFA had good specificity, and there was no significant cross reactivity among the three subtypes of influenza viruses. The simultaneous detection achieved comparable detection limits with individual detections. Therefore, this multi-channel LFA had good application potential for sensitive and rapid detection and subtyping of influenza viruses.

Detection and typing of influenza viruses in vaccinated and non- vaccinated children in central Greece during 2018-2019

During the 2018-2019 influenza season in central Greece, 388 respiratory samples were collected from children presented with influenza symptoms and tested for the detection of influenza viruses. Real-time RT-PCR testing of the samples revealed the presence of influenza A (H1N1) (pdm09), influenza A (H3N2), seasonal influenza A (H1N1), and influenza B viruses. All samples tested were found negative for influenza A(H5) HA gene sequence. The majority of influenza viruses detected were type A (90%), of which the majority, (61%), were influenza A (H1N1) (pdm09) viruses, indicating that these viruses were the dominant influenza subtype circulating in central Greece during the winter and early spring of the aforementioned season.

Hospital surveillance of respiratory viruses during the COVID-19 pandemic and beyond: contribution to the WHO mosaic framework, Israel, 2020 to 2023.

BackgroundA new respiratory virus surveillance platform, based on nationwide hospital laboratory data, was established in Israel during the COVID-19 pandemic.AimWe aimed to evaluate the performance of this platform with respect to the detection of influenza and respiratory syncytial virus (RSV) from week 36 in 2020 to week 15 in 2023, and how it fits with the World Health Organization (WHO) mosaic surveillance framework.MethodsData of respiratory samples from hospitalised patients sent for laboratory confirmation of influenza virus or RSV from 25 general hospital laboratories nationwide were collected. We analysed the weekly number and percentage of samples positive for influenza virus or RSV vis-à-vis SARS-CoV-2 activity and compared data from the new surveillance platform with existing surveillance platforms. Using data in the new surveillance platform, we analysed early stages of a 2021 out-of-season RSV outbreak and evaluated the capabilities of the new surveillance system with respect to objectives and domains of the WHO mosaic framework.ResultsThe new hospital-laboratory surveillance platform captured the activity of influenza virus and RSV, provided crucial data when outpatient sentinel surveillance was not operational and supported an out-of-season RSV outbreak investigation. The new surveillance platform fulfilled important objectives in all three domains of the mosaic framework and could serve for gathering additional information to fulfil more domain objectives.ConclusionThe new hospital laboratory surveillance platform provided essential data during the COVID-19 pandemic and beyond, fulfilled important domain objectives of the mosaic framework and could be adapted for the surveillance of other viruses.

Detection of influenza virus in urban wastewater during the season 2022/2023 in Sicily, Italy.

Seasonal influenza generally represents an underestimated public health problem with significant socioeconomic implications. Monitoring and detecting influenza epidemics are important tasks that require integrated strategies. Wastewater-based epidemiology (WBE) is an emerging field that uses wastewater data to monitor the spread of disease and assess the health of a community. It can represent an integrative surveillance tool for better understanding the epidemiology of influenza and prevention strategies in public health. We conducted a study that detected the presence of Influenza virus RNA using a wastewater-based approach. Samples were collected from five wastewater treatment plants in five different municipalities, serving a cumulative population of 555,673 Sicilian inhabitants in Italy. We used the RT-qPCR test to compare the combined weekly average of Influenza A and B viral RNA in wastewater samples with the average weekly incidence of Influenza-like illness (ILI) obtained from the Italian national Influenza surveillance system. We also compared the number of positive Influenza swabs with the viral RNA loads detected from wastewater. Our study investigated 189 wastewater samples. Cumulative ILI cases substantially overlapped with the Influenza RNA load from wastewater samples. Influenza viral RNA trends in wastewater samples were similar to the rise of ILI cases in the population. Therefore, wastewater surveillance confirmed the co-circulation of Influenza A and B viruses during the season 2022/2023, with a similar trend to that reported for the weekly clinically confirmed cases. Wastewater-based epidemiology does not replace traditional epidemiological surveillance methods, such as laboratory testing of samples from infected individuals. However, it can be a valuable complement to obtaining additional information on the incidence of influenza in the population and preventing its spread.

Detection and genomic characterization of an avian influenza virus A/mute swan/Mangystau/1-S24R-2/2024 (H5N1; clade 2.3.4.4b) strain isolated from the lung of a dead swan in Kazakhstan.

The influenza virus strain A/mute swan/Mangystau/1-S24R-2/2024 (H5N1; clade 2.3.4.4b) was isolated in embryonated chicken eggs from the lung of a dead swan found around Lake Karakol (Kazakhstan) during a highly pathogenic avian influenza outbreak in 2024. The aim of this study was to characterize the genetic profile of the isolated strain.