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It is difficult to differentiate between coronavirus disease 2019 (COVID-19) and influenza based on the symptoms. In the present study, a newly developed antigen rapid diagnostic test (Ag-RDT) called Panbio™ COVID-19/Flu A&B that can simultaneously detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/B virus was evaluated. Its accuracy was evaluated using 235 pairs of nasopharyngeal samples collected from patients with respiratory symptoms and fever (>37.5°C). Reverse transcription polymerase chain reaction was used as a reference method to evaluate the accuracy of the SARS-CoV-2 detection. We confirmed the accuracy of the developed Ag-RDT against the Omicron variant where the sensitivity and specificity were 94.8% and 100%, respectively. In addition, to identify the influenza A virus, a noninferiority test was conducted using a commercial Ag-RDT, which has a sensitivity and specificity in comparison with viral culture of 94.8% and 98.4%, respectively. The positive and negative predictive values for influenza A virus were 98.5% and 98.1%, respectively, for the Panbio COVID-19/Flu A&B test. The evaluation of this newly developed Ag-RDT using clinical samples suggests that it has a high efficacy in clinical settings. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a major pathogen responsible for severe complications in patients with prior influenza A virus (IAV) infection. We have previously demonstrated that S. pneumoniae exhibits increased intracellular survival within IAV-infected cells. Fluoroquinolones (FQs) are widely used to treat pneumococcal infections. However, our prior work has shown that S. pneumoniae can develop intracellular FQ persistence, a phenomenon triggered by oxidative stress within host cells. This persistence allows the bacteria to withstand high FQ concentrations. In this study, we show that IAV infection enhances pneumococcal FQ persistence during intracellular survival within pneumocytes, macrophages, and neutrophils. This enhancement is partly due to increased oxidative stress induced by the viral infection. We find that this phenotype is particularly pronounced in autophagy-proficient host cells, potentially resulting from IAV-induced blockage of autophagosome-lysosome fusion. Moreover, we identified several S. pneumoniae genes involved in oxidative stress response that contribute to FQ persistence, including sodA (superoxide dismutase), clpL (chaperone), nrdH (glutaredoxin), and psaB (Mn+2 transporter component). Our findings reveal a novel mechanism of antibiotic persistence promoted by viral infection within host cells. This underscores the importance of considering this phenomenon when using FQs to treat pneumococcal infections, especially in patients with concurrent influenza A infection. [ABSTRACT FROM AUTHOR]

Acute respiratory tract infections, including influenza A (FluA), respiratory syncytial virus (RSV) infection, and COVID-19, can aggravate to levels requiring hospitalization, increasing morbidity and mortality. Identifying biomarkers for an accurate diagnosis and prognosis of these infections is a clinical need. We performed a cross-sectional study aimed to investigate the changes in circulating levels of arachidonic acid, interleukin 6 (IL-6), and C-reactive protein (CRP) in patients with FluA, RSV, or COVID-19, and to analyze the potential of these parameters as diagnosis or prognosis biomarkers. We analyzed serum samples from 172 FluA, 80 RSV, and 217 COVID-19 patients, and 104 healthy volunteers. Individuals with lung viral diseases showed reduced arachidonic acid concentrations compared to healthy people, with these differences being most pronounced in the order COVID-19 > RSV > FluA. Conversely, IL-6 and CRP levels were elevated across diseases, with IL-6 emerging as the most promising diagnostic biomarker, with areas under the curve (AUC) of the receiver operating characteristics plot higher than 0.85 and surpassing arachidonic acid and CRP. Moreover, IL-6 displayed notable efficacy in distinguishing between FluA patients who survived and those who did not (AUC = 0.80). These findings may provide useful tools for diagnosing and monitoring the severity of acute viral respiratory tract infections, ultimately improving patient outcomes. [ABSTRACT FROM AUTHOR]

Objective: This study compared the clinical presentations and disease severity between influenza A and B (FLUA and FLUB). Materials and Methods: The study included children hospitalized with virologically confirmed influenza between 2010 and 2020. The severity of the disease was evaluated based on admission to the pediatric intensive care unit (PICU), mechanical ventilation requirement, length of hospital stay, length of stay in the PICU, and death. Influenza viruses were compared within predefined age groups (0-2, 3-9, and 10-18 years) and in all age groups. Results: Of 343 patients, FLUA and FLUB were detected in 75.8% and 24.2% of children, respectively. FLUB was associated with a higher incidence of headache and abdominal pain (P < .001 and P = .01). Children with FLUB were prescribed antibiotics and antivirals 0.56 and 0.58- fold fewer than those with FLUA. Headache and abdominal pain rates were higher in patients between 3 and 9 years with FLUB. Children between 0 and 2 years with FLUA were more frequently admitted to the PICU than those with FLUB (23.6% vs. 4.0%; P < .004). Eight patients with FLUA died, while only 1 with FLUB died (P = .69). Conclusion: The clinical presentation of FLUA and FLUB appeared similar, except for headache and abdominal pain, which were more prevalent in older patients with FLUB. Our study revealed that children between 0 and 2 years with FLUA were at a significantly higher risk for admission to the PICU. As a result, greater attention and awareness should be paid to children under 2 years old with FLUA. [ABSTRACT FROM AUTHOR]

In Sicily (Italy), respiratory syncytial virus (RSV), rhinovirus (HRV), and influenza virus triggered epidemics among children, resulting in an increase in acute respiratory tract infections (ARTIs). Our objective was to capture the epidemiology of respiratory infections in children, determining which pathogens were associated with respiratory infections following the lockdown and whether there were changes in the epidemiological landscape during the post-SARS-CoV-2 pandemic era. Materials and Methods: We analyzed multiplex respiratory viral PCR data (BioFire® FilmArray® Respiratory Panel 2.1 Plus) from 204 children presenting with respiratory symptoms and/or fever to our Unit of Pediatrics and Pediatric Emergency. Results: Viruses were predominantly responsible for ARTIs (99%), with RSV emerging as the most common agent involved in respiratory infections, followed by human rhinovirus/enterovirus and influenza A. RSV and rhinovirus were also the primary agents in coinfections. RSV predominated during winter months, while HRV/EV exhibited greater prevalence than RSV during the fall. Some viruses spread exclusively in coinfections (human coronavirus NL63, adenovirus, metapneumovirus, and parainfluenza viruses 1–3), while others primarily caused mono-infections (influenza A and B). SARS-CoV-2 was detected equally in both mono-infections (41%) and coinfections (59%). Conclusions: Our analysis underlines the predominance of RSV and the importance of implementing preventive strategies for RSV. [ABSTRACT FROM AUTHOR]

Objective: To investigate the application value of peripheral blood routine indicators in children with preliminary positive influenza A virus screening. Methods: 378 children with influenza A admitted to our hospital from March 1st 2023 to April 19th 2023 were collected as research group, another 378 healthy children were collected as control group, the peripheral blood routine indicators white blood cell(WBC), neutrophilic granulocyte(Neu), lymphocyte(Lym), monocyte(Mon), platelet count(PLT), platelet distribution width(PDW), NLR, LMR and PLR of two groups were detected, the predictive value of peripheral blood routine indicators for early screening diagnosis of influenza A in children with different ages were evaluated by ROC curve. Results: The detected number of boys was higher than girls of 378 cases, toddler stage(＞12 and ≤36 months) and preschool stage(＞36 and ≤72 months) children were more than other age stages. The WBC, Lym, PLT and LMR of research group were lower than control group, while Neu, Mon, PDW, NLR and PLR were higher (P＜0.05). The peripheral blood routine indicators in children with different ages had certain extent difference s(P＜0.05), different peripheral blood routine indicators had superior application values of children in different ages. Conclusion: Peripheral blood routine indicators show superior application values for early screening diagnosis of influenza A in children with different ages, which can provide certain help for clinical early diagnosis, early prevention and control, reducing infection rates and mortality. [ABSTRACT FROM AUTHOR]

Background: Respiratory viral infections have significant global health impacts. We compared 30‐day intensive care unit (ICU) admission and all‐cause mortality risks in patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) Delta and Omicron variants versus influenza A and B (A/B). Methods: Data from two retrospective inpatient cohorts in Copenhagen were analyzed. Cohorts included hospitalized influenza A/B patients (2017–2018) and SARS‐CoV‐2 Delta/Omicron patients (2021–2022), aged ≥18 years, admitted within 14 days of a positive real‐time polymerase chain reaction test result. Cumulative ICU admission and mortality rates were estimated using the Aalen–Johansen estimator. Cox regression models calculated hazard ratios (HRs) for ICU admission and mortality. Results: The study encompassed 1459 inpatients (Delta: 49%; Omicron: 26%; influenza A: 6.4%; and influenza B: 18%). Cumulative incidence of ICU admission was 11%, 4.0%, 7.5%, and 4.1%, for Delta, Omicron, influenza A, and B, respectively. For ICU admission, adjusted HRs (aHRs) were 3.1 (p <.001) and 1.5 (p =.34) for Delta and Omicron versus influenza B, and 1.5 (p =.36) and 0.71 (p =.48) versus influenza A. For mortality, aHRs were 3.8 (p <.001) and 3.4 (p <.001) for Delta and Omicron versus influenza B, and 2.1 (p =.04) and 1.9 (p =.11) versus influenza A. Conclusion: Delta but not Omicron inpatients had an increased risk for ICU admission compared to influenza B; however, both variants were associated with higher risks of mortality than influenza B. Only Delta inpatients had a higher risk of mortality than influenza A inpatients. [ABSTRACT FROM AUTHOR]

In March 2024, clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus (HPAIV) was detected in dairy cattle in the US, and it was discovered that the virus could be detected in raw milk. Although affected cow’s milk is diverted from human consumption and current pasteurization requirements are expected to reduce or eliminate infectious HPAIV from the milk supply, a study was conducted to characterize whether the virus could be detected by quantitative real-time RT-PCR (qrRT-PCR) in pasteurized retail dairy products and, if detected, to determine whether the virus was viable. From 18 April to 22 April 2024, a total of 297 samples of Grade A pasteurized retail milk products (23 product types) were collected from 17 US states that represented products from 132 processors in 38 states. Viral RNA was detected in 60 samples (20.2%), with qrRT-PCRbased quantity estimates (non-infectious) of up to 5.4log1050% egg infectious doses per mL, with a mean and median of 3.0log10/mL and 2.9log10/mL, respectively. Samples that were positive for type A influenza by qrRT-PCR were confirmed to be clade 2.3.4.4 H5 HPAIV by qrRT-PCR. No infectious virus was detected in any of the qrRT-PCR-positive samples in embryonating chicken eggs. Further studies are needed to monitor the milk supply, but these results provide evidence that the infectious virus did not enter the US pasteurized milk supply before control measures for HPAIV were implemented in dairy cattle. IMPORTANCE Highly pathogenic avian influenza virus (HPAIV) infections in US dairy cattle were first confirmed in March 2024. Because the virus could be detected in raw milk, a study was conducted to determine whether it had entered the retail food supply. Pasteurized dairy products were collected from 17 states in April 2024. Viral RNA was detected in one in five samples, but infectious virus was not detected. This provides a snapshot of HPAIV in milk products early in the event and reinforces that with current safety measures, infectious viruses in milk are unlikely to enter the food supply. [ABSTRACT FROM AUTHOR]

Wastewater-based epidemiology (WBE) is a valuable disease surveillance tool. However, little is known on how factors such as transportation, storage, and wastewater characteristics influence the accuracy of the quantification methods. Hence, this study investigated the impact of storage temperatures and physicochemical characteristics of wastewater on SARS-CoV-2 and influenza A stability using droplet digital PCR. Additionally, strategies to enhance viral recovery were explored. Municipal influent wastewater stored between ±25 and −80 °C was assessed for a period of 84 days to determine viral degradation. Degradation up to 94.1% of influenza A and SARS-CoV-2 was observed in all samples with the highest at ±25 °C. Viral degradation was correlated to the changes in wastewater physicochemical characteristics. The low degradation observed of SARS-CoV-2 in the spiked pellets were indicative of viral adhesion to wastewater solids, which correlated with changes in pH. Ultrasonication frequencies ranging from 4 to 16 kHz, increased SARS-CoV-2 concentrations in the supernatant between 3.30 and 35.65%, indicating viral RNA attachment to wastewater solids. These results highlight the importance of additional pretreatment methods for maximizing RNA recovery from wastewater samples. Based on these findings, it was deduced that wastewater preservation studies are essential, and pretreatment should be included in the WBE methodology. HIGHLIGHTS SARS-CoV-2 and influenza A degradation observed at all storage temperatures.; Changes in physicochemical characteristics influenced viral degradation.; pH influenced viral affinity for wastewater solids.; Ultrasonication led to the detachment of SARS-CoV-2 from wastewater solids, increasing concentrations by up to 35.65%.;

Since influenza and COVID-19 cause similar symptoms, the need for selective, sensitive and practical systems for influenza A detection has been highlighted. For this reason, in this work, a graphene (Gr) based nanomaterial modified anti-hemagglutinine 3, from now on will be called Gr-antiH3, based disposible electrochemical influenza immunosensor was developed. In order to obtain the highest sensitivity, the effects of various Gr-based nanomaterials on developed electrochemical immunosensor responses were investigated. For this purpose, graphene oxide, Gr, Gr-platinum (Gr-Pt), Gr-gold and Gr-gold-platinum nanomaterials were synthesized and characterized via electrochemical impedance spectroscopy (EIS). As a result, since the best results were obtained with Gr-Pt, this nanomaterial was integrated into H3N2 immunosensor system as a modifier. The Gr-Pt modified immunosensor was shown to provide a linear range from 0.5 µg/mL to 7 µg/mL. The limit of detection was 0.38 µg/mL and limit of quantification was 1.28 µg/mL with a relative standard deviation of 3.05%. The developed biosensor was applied to H3N2 detection in synthetic saliva samples and promising results were obtained with recoveries of 100.41 ± 1.10%. [ABSTRACT FROM AUTHOR]

This study analyzed the role of electric charge in human viral infections. Examples of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), dengue, Ebola, influenza A, and respiratory syncytial virus (RSV) are presented. Charge distribution in SARS-CoV-2 and electrostatic interactions of SARS-CoV-2 with its receptor, angiotensin-converting enzyme 2 (ACE2), were evaluated, and the mean time required for respired SARS-CoV-2 virus attachment was evaluated. The virus–cell attachment modality of all of the above viruses was calculated. The impact of electric charge on other viral-related processes, such as replication of virion material, release, and immune response, was also discussed. Special charge conditions in virus treatments were also indicated.

Abstract Background After the occurrence of the COVID-19 pandemic, detection of other disseminated respiratory viruses using highly sensitive molecular methods was declared essential for monitoring the spread of health-threatening viruses in communities. The development of multiplex molecular assays are essential for the simultaneous detection of such viruses even at low concentrations. In the present study, a highly sensitive and specific multiplex one-step droplet digital PCR (RT-ddPCR) assay was developed for the simultaneous detection and absolute quantification of influenza A (IAV), influenza B (IBV), respiratory syncytial virus (RSV), and beta-2-microglobulin transcript as an endogenous internal control (IC B2M). Results The assay was first evaluated for analytical sensitivity and specificity, linearity, reproducibility, and recovery rates with excellent performance characteristics and then applied to 37 wastewater samples previously evaluated with commercially available and in-house quantitative real-time reverse transcription PCR (RT-qPCR) assays. IAV was detected in 16/37 (43%), IBV in 19/37 (51%), and RSV in 10/37 (27%) of the wastewater samples. Direct comparison of the developed assay with real-time RT-qPCR assays showed statistically significant high agreement in the detection of IAV (kappa Cohen’s correlation coefficient: 0.834, p = 0.001) and RSV (kappa: 0.773, p = 0.001) viruses between the two assays, while the results for the detection of IBV (kappa: 0.355, p = 0.27) showed good agreement without statistical significance. Conclusions Overall, the developed one-step multiplex ddPCR assay is cost-effective, highly sensitive and specific, and can simultaneously detect three common respiratory viruses in the complex matrix of wastewater samples even at low concentrations. Due to its high sensitivity and resistance to PCR inhibitors, the developed assay could be further used as an early warning system for wastewater monitoring.

Abstract Background The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), influenza A, and respiratory syncytial virus (RSV) infections have similar modes of transmission and clinical symptoms. There is a need to identify simple diagnostic indicators to distinguish these three infections, particularly for community hospitals and low- and middle-income countries that lack nucleic acid detection kits. This study used clinical data to assess the diagnostic value of routine blood tests in differentiating between SARS-CoV-2, influenza A, and RSV infections in children. Methods A total of 1420 children treated at the Hangzhou Children’s Hospital between December 2022 and June 2023 were enrolled in this study, of whom 351 had SARS-CoV-2, 671 had influenza, and 398 had RSV. In addition, 243 healthy children were also collected. The blood test results of SARS-CoV-2 patients were compared to those of patients with influenza A and RSV and the healthy controls. The area under the receiver operating characteristic curve (AUC-ROC) was employed to evaluate each blood parameter’s diagnostic value. Results Children with SARS-CoV-2 exhibited notably elevated levels of white blood cell (WBC) count, platelet (PLT) count, neutrophil count, and neutrophil-to-lymphocyte ratio (NLR) compared to influenza A patients (P

The aim of this study is to describe the novel epidemiological and clinical characteristics of influenza A-induced severe pneumonia occurring after the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to further assess its potential risk factors for mortality.

Abstract Background Influenza is an acute respiratory infection caused by influenza virus. Maxing Shigan Decoction (MXSGD) is a commonly used traditional Chinese medicine prescription for the prevention and treatment of influenza. However, its mechanism remains unclear. Method The mice model of influenza A virus pneumonia was established by nasal inoculation. After 3 days of intervention, the lung index was calculated, and the pathological changes of lung tissue were detected by HE staining. Firstly, transcriptomics technology was used to analyze the differential genes and important pathways in mouse lung tissue regulated by MXSGD. Then, real-time fluorescent quantitative PCR (RT-PCR) was used to verify the changes in mRNA expression in lung tissues. Finally, intestinal microbiome and intestinal metabolomics were performed to explore the effect of MXSGD on gut microbiota. Results The lung inflammatory cell infiltration in the MXSGD group was significantly reduced (p

Influenza affects individuals of all ages and poses a significant threat during pandemics, epidemics, and sporadic outbreaks. Neuraminidase inhibitors (NAIs) are currently the first choice in the treatment and prevention of influenza, but their use can be hindered by viral resistance. This review summarizes current NAIs pharmacological profiles, their current place in therapy, and the mechanisms of viral resistance and outlines possible new indications, ways of administration, and novel candidate NAIs compounds. NAIs represent a versatile group of compounds with diverse administration methods and pharmacokinetics. While the prevalence of influenza virus resistance to NAIs remains low, there is heightened vigilance due to the pandemic potential of influenza. Several novel NAIs and derivatives are currently under assessment at various stages of development for the treatment and prevention of influenza. [ABSTRACT FROM AUTHOR]

Equine influenza (EI) virus is one of the most economically significant pathogens causing respiratory disorders in equids. The recent outbreaks of EI in equids in North Western Nigeria showed EI virus is circulating in the Northern part of the country. This study determined the seroprevalence of EI infection in horses from the Southwestern states of Nigeria. One hundred sera samples from horses kept in three South Western states: Lagos, Ogun, and Oyo were screened for antibodies against influenza A nucleoprotein antigen using the direct ELISA method. Positive sera samples were thereafter examined thereafter further examined for haemagglutination inhibition (HI) antibodies to the H3 subtype of the influenza A virus. Antibodies were detected in 60 of the horses (22 Lagos, 8 Ogun and 30 Oyo). Although significantly higher seropositivity was observed in the male horses, seroprevalence of EI was also higher among 11- 15 years, exotic breeds and patrol horses. High seropositivity of horses in the South Western states of Nigeria to EIV infection is an indication that adequate monitoring of horse movement and continuous surveillance of the virus and vaccination should be strongly recommended. [ABSTRACT FROM AUTHOR]

Background and Aims: The current study aimed to evaluate the efficiency of Enzyme‐linked immunosorbent assay (ELISA) assay and monoplex and multiplex real‐time reverse‐transcription PCR (rRT‐PCR) in the detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and influenza A and B viruses (Flu A and Flu B). Methods: The SARS‐CoV‐2 ‐specific IgG and IgM antibodies, as well as, Flu A (H1N1 and H3N2 serotypes) and Flu B virus antibodies were determined by ELISA assay. The one‐step qRT‐PCR method was used to detect the SARS‐CoV‐2 in nasopharyngeal swab samples. Furthermore, the presence of Flu A and B viruses was evaluated using probe‐based RT‐PCR. Simultaneous detection of SARS‐CoV‐2, Flu A and B viruses was performed by multiplex rRT‐PCR assay. Results: SARS CoV‐2 IgM and IgG antibodies were detected in 33.3% and 58.3% of patients, respectively. In contrast, the SARS CoV‐2 genome was detected in 50% of patients using the one‐step monoplex RT‐PCR assay. Flu A serotypes H1N1 and H3N2 were found in 16.7% and 8.3% of patients. Probe‐based RT‐PCR revealed that 39.3% of patients were positive for the Flu A virus. Multiplex rRT‐PCR detect the SARS‐CoV‐2, Flu A, and Flu B in 50%, 39.3%, and 19% of samples, respectively. The sensitivity and specificity of multiplex rRT‐PCR assay in comparison to monoplex RT‐PCR were 100% and 55%, respectively. Coinfection with SARS‐CoV‐2, Flu A, and Flu B viruses was found in 9.5% of patients. Conclusion: Multiplex rRT‐PCR can be used as a repaid, cost‐effective and suitable tool for molecular surveillance of SARS‐CoV‐2 and Flu A/B viruses. [ABSTRACT FROM AUTHOR]

Background: After the occurrence of the COVID-19 pandemic, detection of other disseminated respiratory viruses using highly sensitive molecular methods was declared essential for monitoring the spread of health-threatening viruses in communities. The development of multiplex molecular assays are essential for the simultaneous detection of such viruses even at low concentrations. In the present study, a highly sensitive and specific multiplex one-step droplet digital PCR (RT-ddPCR) assay was developed for the simultaneous detection and absolute quantification of influenza A (IAV), influenza B (IBV), respiratory syncytial virus (RSV), and beta-2-microglobulin transcript as an endogenous internal control (IC B2M). Results: The assay was first evaluated for analytical sensitivity and specificity, linearity, reproducibility, and recovery rates with excellent performance characteristics and then applied to 37 wastewater samples previously evaluated with commercially available and in-house quantitative real-time reverse transcription PCR (RT-qPCR) assays. IAV was detected in 16/37 (43%), IBV in 19/37 (51%), and RSV in 10/37 (27%) of the wastewater samples. Direct comparison of the developed assay with real-time RT-qPCR assays showed statistically significant high agreement in the detection of IAV (kappa Cohen's correlation coefficient: 0.834, p = 0.001) and RSV (kappa: 0.773, p = 0.001) viruses between the two assays, while the results for the detection of IBV (kappa: 0.355, p = 0.27) showed good agreement without statistical significance. Conclusions: Overall, the developed one-step multiplex ddPCR assay is cost-effective, highly sensitive and specific, and can simultaneously detect three common respiratory viruses in the complex matrix of wastewater samples even at low concentrations. Due to its high sensitivity and resistance to PCR inhibitors, the developed assay could be further used as an early warning system for wastewater monitoring. [ABSTRACT FROM AUTHOR]

Influenza A (H1N1) viruses are prone to antigenic mutations and are more variable than other influenza viruses. Therefore, they have caused continuous harm to human public health since the pandemic in 2009 and in recent times. Influenza A (H1N1) can be prevented and treated in various ways, such as direct inhibition of the virus and regulation of human immunity. Among antiviral drugs, the use of natural products in treating influenza has a long history, and natural medicine has been widely considered the focus of development programs for new, safe anti-influenza drugs. In this paper, we focus on influenza A (H1N1) and summarize the natural product-derived phytochemicals for influenza A virus (H1N1) prevention and treatment, including marine natural products, flavonoids, alkaloids, terpenoids and their derivatives, phenols and their derivatives, polysaccharides, and derivatives of natural products for prevention and treatment of influenza A (H1N1) virus. We further discuss the toxicity and antiviral mechanism against influenza A (H1N1) as well as the druggability of natural products. We hope that this review will facilitate the study of the role of natural products against influenza A (H1N1) activity and provide a promising alternative for further anti-influenza A drug development. [ABSTRACT FROM AUTHOR]

Background: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), influenza A, and respiratory syncytial virus (RSV) infections have similar modes of transmission and clinical symptoms. There is a need to identify simple diagnostic indicators to distinguish these three infections, particularly for community hospitals and low- and middle-income countries that lack nucleic acid detection kits. This study used clinical data to assess the diagnostic value of routine blood tests in differentiating between SARS-CoV-2, influenza A, and RSV infections in children. Methods: A total of 1420 children treated at the Hangzhou Children's Hospital between December 2022 and June 2023 were enrolled in this study, of whom 351 had SARS-CoV-2, 671 had influenza, and 398 had RSV. In addition, 243 healthy children were also collected. The blood test results of SARS-CoV-2 patients were compared to those of patients with influenza A and RSV and the healthy controls. The area under the receiver operating characteristic curve (AUC-ROC) was employed to evaluate each blood parameter's diagnostic value. Results: Children with SARS-CoV-2 exhibited notably elevated levels of white blood cell (WBC) count, platelet (PLT) count, neutrophil count, and neutrophil-to-lymphocyte ratio (NLR) compared to influenza A patients (P < 0.05). In contrast, SARS-CoV-2 patients exhibited a decrease in the mean platelet volume to platelet count ratio (MPV/PLT) and the lymphocyte-to-monocyte ratio (LMR) when compared to other individuals (P < 0.05). These parameters had an AUC between 0.5 and 0.7. Compared to patients with RSV, SARS-CoV-2 patients had significantly higher MPV/PLT and significantly lower WBC, lymphocyte, PLT, LMR, and lymphocyte multiplied by platelet (LYM*PLT) values (P < 0.05). However, only LYM*PLT had an acceptable diagnostic value above 0.7 for all age groups. Compared to healthy children, children with COVID-19 exhibited elevated NLR and MPV/PLT levels, alongside decreased lymphocyte, PLT, LMR, and LYM*PLT values. (P < 0.05). The AUC of the LMR, LYM*PLT, and PLT were above 0.7 in all age groups, indicating promising diagnostic values. Conclusions: The routine blood parameters among patients with COVID-19, influenza A, and RSV differ significantly early in the disease and could be used by clinicians to discriminate between the 3 types of infection. [ABSTRACT FROM AUTHOR]

Influenza viruses cause highly contagious respiratory diseases that cause millions of deaths worldwide. Rapid detection of influenza viruses is essential for accurate diagnosis and the initiation of appropriate treatment. We developed a loop-mediated isothermal amplification and lateral flow assay (LAMP-LFA) capable of simultaneously detecting influenza A and influenza B. Primer sets for influenza A and influenza B were designed to target conserved regions of segment 7 and the nucleoprotein gene, respectively. Optimized through various primer set ratios, the assay operated at 62 °C for 30 min. For a total of 243 (85 influenza A positive, 58 influenza B positive and 100 negative) nasopharyngeal swab samples, the performance of the influenza A/B multiplex LAMP-LFA was compared with that of the commercial AllplexTM Respiratory Panel 1 assay (Seegene, Seoul, Korea). The influenza A/B multiplex LAMP-LFA demonstrated a specificity of 98% for the non-infected clinical samples, along with sensitivities of 94.1% for the influenza A clinical samples and 96.6% for the influenza B clinical samples, respectively. The influenza A/B multiplex LAMP-LFA showed high sensitivity and specificity, indicating that it is reliable for use in a low-resource environment. [ABSTRACT FROM AUTHOR]

Influenza A is an emerging zoonotic virus with worldwide distribution. To our knowledge, no studies have been conducted to assess influenza A exposure in stray cats in regions with positive cases of wild birds. This study aimed to determine the seroprevalence of anti‐influenza A antibodies in feral cats from a region in Spain with cases of positive wild birds. A cross‐sectional study of stray cats (n = 183) was conducted between March 2022 and March 2023. The presence of antibodies against the influenza A virus was tested using a commercial enzyme‐linked immunosorbent assay kit adapted for this study and confirmed by competitive enzyme‐linked immunosorbent assay for the detection of antibodies against the haemagglutinin H5. During sample collection, none of the cats exhibited clinical signs of illness. Four of the 183 animals tested showed anti‐influenza A antibodies by ELISA, and the seroprevalence of influenza A was 2.19% (95% confidence interval 0.85%–5.48%). Due to the low number of positive cases detected, it appears that cats did not have an important epidemiological role in influenza A transmission during this period. [ABSTRACT FROM AUTHOR]

Background: Influenza is an acute respiratory infection caused by influenza virus. Maxing Shigan Decoction (MXSGD) is a commonly used traditional Chinese medicine prescription for the prevention and treatment of influenza. However, its mechanism remains unclear. Method: The mice model of influenza A virus pneumonia was established by nasal inoculation. After 3 days of intervention, the lung index was calculated, and the pathological changes of lung tissue were detected by HE staining. Firstly, transcriptomics technology was used to analyze the differential genes and important pathways in mouse lung tissue regulated by MXSGD. Then, real-time fluorescent quantitative PCR (RT-PCR) was used to verify the changes in mRNA expression in lung tissues. Finally, intestinal microbiome and intestinal metabolomics were performed to explore the effect of MXSGD on gut microbiota. Results: The lung inflammatory cell infiltration in the MXSGD group was significantly reduced (p < 0.05). The results of bioinformatics analysis for transcriptomics results show that these genes are mainly involved in inflammatory factors and inflammation-related signal pathways mediated inflammation biological modules, etc. Intestinal microbiome showed that the intestinal flora Actinobacteriota level and Desulfobacterota level increased in MXSGD group, while Planctomycetota in MXSGD group decreased. Metabolites were mainly involved in primary bile acid biosynthesis, thiamine metabolism, etc. This suggests that MXSGD has a microbial–gut–lung axis regulation effect on mice with influenza A virus pneumonia. Conclusion: MXSGD may play an anti-inflammatory and immunoregulatory role by regulating intestinal microbiome and intestinal metabolic small molecules, and ultimately play a role in the treatment of influenza A virus pneumonia. [ABSTRACT FROM AUTHOR]

This study analyzed the role of electric charge in human viral infections. Examples of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), dengue, Ebola, influenza A, and respiratory syncytial virus (RSV) are presented. Charge distribution in SARS-CoV-2 and electrostatic interactions of SARS-CoV-2 with its receptor, a ngiotensin-converting enzyme 2 (ACE2), were evaluated, and the mean time required for respired SARS-CoV-2 virus attachment was evaluated. The virus–cell attachment modality of all of the above viruses was calculated. The impact of electric charge on other viral-related processes, such as replication of virion material, release, and immune response, was also discussed. Special charge conditions in virus treatments were also indicated. [ABSTRACT FROM AUTHOR]

Refolding multi-disulfide bonded proteins expressed in E. coli into their native structure is challenging. Nevertheless, because of its cost-effectiveness, handiness, and versatility, the E. coli expression of viral envelope proteins, such as the RBD (Receptor-Binding Domain) of the influenza Hemagglutinin protein, could significantly advance research on viral infections. Here, we show that H1N1-PR8-RBD (27 kDa, containing four cysteines forming two disulfide bonds) expressed in E. coli and was purified with nickel affinity chromatography, and reversed-phase HPLC was successfully refolded into its native structure, as assessed with several biophysical and biochemical techniques. Analytical ultracentrifugation indicated that H1N1-PR8-RBD was monomeric with a hydrodynamic radius of 2.5 nm. Thermal denaturation, monitored with DSC and CD at a wavelength of 222 nm, was cooperative with a midpoint temperature around 55 °C, strongly indicating a natively folded protein. In addition, the 15N-HSQC NMR spectrum exhibited several 1H-15N resonances indicative of a beta-sheeted protein. Our results indicate that a significant amount (40 mg/L) of pure and native H1N1-PR8-RBD can be produced using an E. coli expression system with our refolding procedure, offering potential insights into the molecular characterization of influenza virus infection. [ABSTRACT FROM AUTHOR]

Background: Yinqiaosan decoction (YQSD), a traditional Chinese medicinal recipe, has been employed to treat influenza in China for approximately 300 years. Objective: Our study aimed to explore the mechanisms of YQSD against influenza via in vivo and in vitro experimental studies. Study design: and methods UHPLC-Q-TOF-MS/MS was utilized to examine the substances of the YQSD. The chemical components of YQSD detected by UHPLC-Q-TOF-MS/MS were used for network pharmacology analysis. The antiviral effect of YQSD in vivo was investigated. The potential mechanisms of YQSD in combating influenza, which were predicted from network pharmacology analysis, were validated in vitro. Results: By use of UHPLC-Q-TOF-MS/MS, 97 compounds were identified from YQSD. Network pharmacology analysis revealed that the therapeutic effect of YQSD against influenza may be associated with the regulation of T cell receptors (TCR) and Phosphoinositide 3-Kinase (PI3K)- protein kinase B (Akt) signaling pathways. Treatment with YQSD significantly prolonged the mean survival time of the mice and reduced lung injury due to the influenza A virus in vivo. It was discovered that YQSD efficiently inhibited the expression of inflammation-related cytokines. Moreover, YQSD has been found to significantly reduce the expression levels of cluster of differentiation 3 (CD3), monocyte chemoattractant protein-1 (MCP-1), and H1N1 virus nucleoprotein (NP), and prevent the decrease of epithelial cadherin (E-cadherin) protein. In addition, YQSD can inhibit the phosphorylation of the zeta chain of T cell receptor-associated protein kinase 70 (ZAP70) and PI3K proteins in vitro. Conclusion: The capacity of YQSD to suppress viral multiplication and inflammatory response by modulating T cell immunity may explain its effect against influenza viral pneumonia, which may involve the regulation of TCR and PI3K signaling pathways.

ABSTRACT Outbreaks of influenza A viruses are generally seasonal and cause annual epidemics worldwide. Due to their frequent reassortment and evolution, annual surveillance is of paramount importance to guide vaccine strategies. The aim of this study was to explore the molecular epidemiology of influenza A virus and nasopharyngeal microbiota composition in infected patients in Saudi Arabia. A total of 103 nasopharyngeal samples from 2015 and 12 samples from 2022 were collected from patients positive for influenza A. Sequencing of influenza A as well as metatranscriptomic analysis of the nasopharyngeal microbiota was conducted using Oxford Nanopore sequencing. Phylogenetic analysis of hemagglutinin, neuraminidase segments, and concatenated influenza A genomes was performed using MEGA7. Whole-genome sequencing analysis revealed changing clades of influenza A virus: from 6B.1 in 2015 to 5a.2a in 2022. One sample containing the antiviral resistance-mediating mutation S247N toward oseltamivir and zanamivir was found. Phylogenetic analysis showed the clustering of influenza A strains with the corresponding vaccine strains in each period, thus suggesting vaccine effectiveness. Principal component analysis and alpha diversity revealed the absence of a relationship between hospital admission status, age, or gender of infected patients and the nasopharyngeal microbial composition, except for the infecting clade 5a.2a. The opportunistic pathogens Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were the most common species detected. The molecular epidemiology appears to be changing in Saudi Arabia after the COVID-19 pandemic. Antiviral resistance should be carefully monitored in future studies. In addition, the disease severity of patients as well as the composition of the nasopharyngeal microbiota in patients infected with different clades should also be assessed.IMPORTANCEIn this work, we have found that the clade of influenza A virus circulating in Riyadh, KSA, has changed over the last few years from 6B.1 to 5a.2a. Influenza strains clustered with the corresponding vaccine strains in our population, thus emphasizing vaccine effectiveness. Metatranscriptomic analysis showed no correlation between the nasopharyngeal microbiome and the clinical and/or demographic characteristics of infected patients. This is except for the 5a.2a strains isolated post-COVID-19 pandemic. The influenza virus is among the continuously evolving viruses that can cause severe respiratory infections. Continuous surveillance of its molecular diversity and the monitoring of anti-viral-resistant strains are thus of vital importance. Furthermore, exploring potential microbial markers and/or dysbiosis of the nasopharyngeal microbiota during infection could assist in the better management of patients in severe cases.

Abstract Background Respiratory viral infections have significant global health impacts. We compared 30‐day intensive care unit (ICU) admission and all‐cause mortality risks in patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) Delta and Omicron variants versus influenza A and B (A/B). Methods Data from two retrospective inpatient cohorts in Capital Region of Denmark were analyzed. Cohorts included hospitalized influenza A/B patients (2017–2018) and SARS‐CoV‐2 Delta/Omicron patients (2021–2022), aged ≥18 years, admitted within 14 days of a positive real‐time polymerase chain reaction test result. Cumulative ICU admission and mortality rates were estimated using the Aalen–Johansen estimator. Cox regression models calculated hazard ratios (HRs) for ICU admission and mortality. Results The study encompassed 1459 inpatients (Delta: 49%; Omicron: 26%; influenza A: 6.4%; and influenza B: 18%). Cumulative incidence of ICU admission was 11%, 4.0%, 7.5%, and 4.1%, for Delta, Omicron, influenza A, and B, respectively. For ICU admission, adjusted HRs (aHRs) were 3.1 (p

Streptococcus pneumoniae is a major pathogen responsible for severe complications in patients with prior influenza A virus (IAV) infection. We have previously demonstrated that S. pneumoniae exhibits increased intracellular survival within IAV-infected cells. Fluoroquinolones (FQs) are widely used to treat pneumococcal infections. However, our prior work has shown that S. pneumoniae can develop intracellular FQ persistence, a phenomenon triggered by oxidative stress within host cells. This persistence allows the bacteria to withstand high FQ concentrations. In this study, we show that IAV infection enhances pneumococcal FQ persistence during intracellular survival within pneumocytes, macrophages, and neutrophils. This enhancement is partly due to increased oxidative stress induced by the viral infection. We find that this phenotype is particularly pronounced in autophagy-proficient host cells, potentially resulting from IAV-induced blockage of autophagosome-lysosome fusion. Moreover, we identified several S. pneumoniae genes involved in oxidative stress response that contribute to FQ persistence, including sodA (superoxide dismutase), clpL (chaperone), nrdH (glutaredoxin), and psaB (Mn+2 transporter component). Our findings reveal a novel mechanism of antibiotic persistence promoted by viral infection within host cells. This underscores the importance of considering this phenomenon when using FQs to treat pneumococcal infections, especially in patients with concurrent influenza A infection.

This case report illuminates an instance of Ludwig’s Angina in a 16-year-old male patient with concurrent Influenza A. Ludwig’s Angina, a potentially fatal, rapidly spreading cellulitis, primarily affects the submandibular and sublingual spaces. This case emphasizes the importance of early detection, immediate intervention, and multidisciplinary management to prevent life-threatening complications. The patient presented with fever, sore throat, swelling under the tongue and submandibular region, and difficulty breathing following a family trip to Puerto Rico. Despite initial respiratory distress and severe soft tissue swelling, the patient responded positively to broad-spectrum antibiotics, with clinical improvement leading to discharge after five days. The report discusses the challenges in diagnosing and managing Ludwig’s Angina, the potential role of the patient’s environment in disease presentation, and the relevance of historical medical literature in contemporary clinical practice. This case underscores the need for vigilance in patients with influenza for potential secondary bacterial complications and the necessity of expedited airway management in patients with Ludwig’s Angina. [ABSTRACT FROM AUTHOR]