Severe Influenza Cases Research Articles

Resurgence of influenza and enterovirus infections in Taiwan post-COVID-19: A nationwide surveillance study

BackgroundThe global impact of COVID-19 has prompted profound shifts in public health policies. The epidemiology of respiratory infectious disease may change in the post-covid era. This study investigates the repercussions of these policies on respiratory infectious diseases, specifically the resurgence of severe influenza and enterovirus infections in the post-COVID-19 era. MethodsExamining the period from January 2020 to December 2023, our nationwide study analyzes data from the Taiwan Centers for Disease Control and Our World in Data. Two distinct phases, containing (Week 1, 2020, to Week 43, 2022) and coexisting (Week 44, 2022, to Week 50, 2023), are scrutinized, emphasizing policy changes and their potential impact on epidemiology. ResultsEpidemiological trends reveal a decline in COVID-19 and all-cause pneumonia during the co-existing period but a notable rise in severe influenza and enterovirus infections. Interrupted time series analysis confirms the surge in severe influenza and enterovirus cases post-restriction ease. ConclusionThe post-COVID-19 era introduces challenges with the resurgence of traditional respiratory diseases, necessitating continuous surveillance, timely non-pharmaceutical interventions, and vaccination as crucial strategies. Vigilance and targeted measures by policymakers and healthcare providers are imperative to navigate the evolving landscape of respiratory infectious diseases in the aftermath of the pandemic.

H1N1 nanobody development and therapeutic efficacy verification in H1N1-challenged mice

Influenza A virus causes numerous deaths and infections worldwide annually. Therefore, we have considered nanobodies as a potential treatment for patients with severe cases of influenza. We developed a nanobody that was expected to have protective efficacy against the A/California/04/2009 (CA/04; pandemic 2009 flu strain) and evaluated its therapeutic efficacy against CA/04 in mice experiments. This nanobody was derived from the immunization of the alpaca, and the inactivated CA/04 virus was used as an immunogen. We successfully generated a nanobody library through bio-panning, phage ELISA, and Bio-layer interferometry. Moreover, we confirmed that administering nanobodies after lethal doses of CA/04 reduced viral replication in the lungs and influenza-induced clinical signs in mice. These research findings will help to develop nanobodies as viral therapeutics for CA/04 and other infectious viruses.

Effectiveness of influenza vaccine in preventing severe cases of influenza: Season 2022/2023

IntroductionInfluenza poses a significant burden in terms of morbidity and mortality, with vaccination being one of the most effective measures for its prevention. Therefore, the aim of this study is to determine the effectiveness of the influenza vaccine in preventing cases of severe influenza in patients admitted to a tertiary hospital during the 2022/23 season. MethodsCase-control study. All hospitalised patients with a positive result in an RT-PCR for influenza were included. Those who met the criteria for a severe case (pneumonia, sepsis, multi-organ failure, admission to ICU or exitus) were considered cases. Those who did not meet these criteria were considered controls. Vaccine effectiveness (VE) to prevent severe cases and its 95% confidence interval were calculated. ResultsA total of 403 patients were admitted with confirmed influenza. Of these, 98 (24.3%) developed severe influenza. Of the total, 50.6% were men and 47.1% were over 65 years of age. VE adjusted for influenza type, age and certain comorbidities was 40.6% (−21.9 to 71.1). In a segmented analysis, influenza vaccine was effective in preventing severe cases in all categories. It was particularly relevant in the 65+ age group (VEa = 60.9%; −2.0 to 85.0) and in patients with influenza A (VEa = 56.7%; 1.5–80.9). ConclusionInfluenza vaccination markedly reduced the occurrence of severe cases of influenza in hospitalised patients, therefore, it remains the main strategy to reduce morbidity and mortality and associated costs.

Effectiveness of Influenza Vaccination and Early Antiviral Treatment in Reducing Pneumonia Risk in Severe Influenza Cases.

Influenza vaccination may be effective in preventing influenza infection and may reduce the risk of influenza-associated pneumonia. The study aim was to evaluate the effect of influenza vaccination in preventing pneumonia when it failed to prevent influenza hospitalization. This was a case-control study comparing hospitalized cases of influenza with and without pneumonia in patients aged ≥18 years in 16 hospitals in Catalonia over 10 influenza seasons (2010-11 to 2019-20). Data on sociodemographic, virological characteristics, comorbidities, vaccination history, and antiviral treatment were collected and analysed. The crude odds ratio (OR) and adjusted OR (aOR) with the corresponding 95% confidence interval (CI) values were calculated. In total, 5080 patients hospitalized for severe influenza were included, 63.5% (3224/5080) of whom had pneumonia-mostly men (56.8%; 1830/3224) and mostly in the ≥75 age group (39.3%; 1267/3224)-and of whom 14.0% died (451/3224). Virus A and virus B accounted for 78.1% (2518/3224) and 21.9% (705/3224) of influenza types, respectively. Starting antiviral treatment ≤48 h after symptom onset (aOR = 0.69; 95%CI: 0.53-0.90) and a history of seasonal influenza vaccination (aOR = 0.85; 95%CI: 0.72-0.98) were protective factors in developing pneumonia. Adherence to seasonal influenza vaccination and starting antiviral treatment within 48 h of symptom onset can reduce pneumonia risk in severe influenza cases.

An Investigation of Severe Influenza Cases in Russia during the 2022-2023 Epidemic Season and an Analysis of HA-D222G/N Polymorphism in Newly Emerged and Dominant Clade 6B.1A.5a.2a A(H1N1)pdm09 Viruses.

In Russia, during the COVID-19 pandemic, a decrease in influenza circulation was initially observed. Influenza circulation re-emerged with the dominance of new clades of A(H3N2) viruses in 2021-2022 and A(H1N1)pdm09 viruses in 2022-2023. In this study, we aimed to characterize influenza viruses during the 2022-2023 season in Russia, as well as investigate A(H1N1)pdm09 HA-D222G/N polymorphism associated with increased disease severity. PCR testing of 780 clinical specimens showed 72.2% of them to be positive for A(H1N1)pdm09, 2.8% for A(H3N2), and 25% for influenza B viruses. The majority of A(H1N1)pdm09 viruses analyzed belonged to the newly emerged 6B.1A.5a.2a clade. The intra-sample predominance of HA-D222G/N virus variants was observed in 29% of the specimens from A(H1N1)pdm09 fatal cases. The D222N polymorphic variant was registered more frequently than D222G. All the B/Victoria viruses analyzed belonged to the V1A.3a.2 clade. Several identified A(H3N2) viruses belonged to one of the four subclades (2a.1b, 2a.3a.1, 2a.3b, 2b) within the 3C.2a1b.2a.2 group. The majority of antigenically characterized viruses bore similarities to the corresponding 2022-2023 NH vaccine strains. Only one influenza A(H1N1)pdm09 virus showed reduced inhibition by neuraminidase inhibitors. None of the influenza viruses analyzed had genetic markers of reduced susceptibility to baloxavir.

Influenza vaccination mitigates severe complications in hospitalized patients: A ten-year observational study, Spain, 2009-2019

Influenza epidemics annually impact a substantial portion of adults worldwide, leading to numerous hospitalizations and fatalities. While the primary goal of vaccination is to prevent influenza virus infection, breakthrough infections can still occur despite vaccination. Evaluating the vaccine effectiveness in preventing severe cases among hospitalized patients is crucial for enhancing vaccination strategies. This single-center, observational, cross-sectional, and retrospective study analyzed data from 1,357 patients admitted to La Paz University Hospital for influenza infection between 2009 and 2019. Patients' demographics, clinical variables, comorbidities, vaccination status, and influenza-related outcomes were assessed. Logistic regression analysis was performed to determine the vaccine-independent protective effects. Influenza vaccination independently prevented severe complications, including pneumonia, bacterial superinfection, acute respiratory distress syndrome, and multiple organ failure in hospitalized patients (odds ratio=0.61, 95% confidence interval: 0.47-0.76). Vaccinated patients had significantly lower intensive care unit admission rates (odds ratio=0.42, 95% confidence interval: 0.18-0.92). However, there were no significant differences in mortality rates between vaccinated and unvaccinated patients (P=.385). Our study provides robust evidence supporting the influenza vaccine protective effect against severe outcomes in hospitalized patients during epidemic flu. Vaccination is associated with a significant reduction in severe complications and intensive care unit admissions, emphasizing its importance as a preventive measure. Improving vaccination coverage, especially in specific comorbidities and age groups, could further enhance the vaccine effectiveness in preventing severe influenza cases.

Unveiling the Uncommon: A Paediatric Case of Influenza-Related Atrioventricular Block

This case report highlights a 5-year-old child who developed a first-degree atrioventricular (AV) block during an influenza B infection. Influenza is a common viral illness that can cause severe morbidity and mortality, especially in children with underlying medical conditions. The case emphasizes the potential cardiac complications of influenza and the need for prompt recognition in paediatric patients. The child presented with bradycardia and a prolonged PR interval on the electrocardiogram, indicating AV block. The child had no other symptoms and was discharged in stable condition after two days of observation. Prompt recognition and evaluation of cardiac manifestations in influenza-infected patients, including thorough medical history and diagnostic workup, are crucial for the timely management and prevention of long-term sequelae. This case underscores the importance of considering cardiac complications in severe cases of influenza, especially in the paediatric population, and emphasizes the need for healthcare providers to be vigilant in identifying potential cardiac manifestations during influenza outbreaks.

Knowledge, Attitude, and Practice towards Influenza Vaccination among Older Adults in Southern China during the COVID-19 Pandemic.

Influenza is prevalent globally, leading to severe morbidity and mortality. During the pandemic, knowledge, attitude, and practice (KAP) towards influenza virus and vaccination were less investigated among southern Chinese older adults. A cross-sectional study was conducted through the structured questionnaire among community healthcare centers in selected districts in Shenzhen, southern China from September to October 2021. KAP towards influenza virus and vaccination were analyzed. A multivariable logistic regression model was used to identify associated factors. Among 975 participants, 55.6% were reported to have received influenza vaccination ever, and 46.6% had taken influenza vaccination in 2020 during the pandemic. Only one-fifth of participants knew severe comorbidities happen among severe influenza cases. A total of 88.3% thought older adults should have influenza vaccination. COVID-19 vaccination history was associated with receiving influenza vaccination (OR 1.92, 95% CI 1.32-2.80). People with a high-level income had better KAP towards influenza virus and vaccination. COVID-19 vaccination history was associated with the positive actions of influenza vaccination during the pandemic. Efforts should be made to promote the free influenza vaccination program widely and launch health education events on influenza and its vaccination regularly to improve KAP among older adults.

Influenza in Pregnancy

Pregnant women should avoid places with too many people during a influenza epidemic and people who already have influenza. The immune system of pregnant women is very sensitive and prone to attacks by viruses and bacteria, and the treatment of flu during pregnancy takes longer than usual. Influenza during pregnancy can increase the duration of the infection and can lead to more serious complications, such as pneumonia. More severe cases of influenza in pregnant women can end up in hospitalization of pregnant women. As the influenza has a bad effect on the health of the pregnant woman herself, it can unfortunately also affect the fetus and can lead to the birth of a child with a low birth weight and premature birth.

Initial and severe cases of influenza in 2020-2022 and population immunity prior to epidemic season

The purpose of the present work was to evaluate population immunity to influenza and molecular genetic analysis of influenza viruses detected in the Russian Federation over 2020-2022. In this study, 1344 samples of blood serum collected prior to the 2021-2022 flu season in Siberian, Southern, Far Eastern, Volga and Ural Federal Districts were studied. Seropositivity to the A/Victoria/2570/2019 vaccine strain (H1N1) pdm09 was detected in 25% to 31% of samples from the four federal districts, and in 8% of samples from the Far Eastern Federal District. Seropositivity to the A/Cambodia/e0826360/2020 strain (H3N2) was detected in 24% to 37% of the samples. The lowest population immunity was revealed to the influenza B/Washington/02/2019 vaccine strain (Victoria lineage), with < 10% of serum samples reactive to the studied strain. Since March 2020, the worldwide turnover of all seasonal respiratory viruses has sharply decreased, except of rhinoviruses. From March 2020 to June 2021, we have identified six B/Victoria influenza viruses from sporadic cases of influenza. From June 2021 to the end February 2022, the State Research Center “Vector” received 901 samples positive for influenza A(H3N2) virus RNA, two specimens positive for A(H1N1) pdm09 virus RNA, and 17 samples positive for influenza B. All studied A(H3N2) viruses belonged to the 3C.2a1b.2a2 subclade (Bangladesh group). The two verified A(H1N1) pdm09 influenza viruses belonged to the 6B.1A.5a clade. All studied influenza B viruses were assigned to the B/Victoria genetic lineage, and to 1A.3a2 subclade. The genomes of all identified viruses did not contain mutations of the NA gene responsible for drug resistance to neuraminidase inhibitors, or mutations in РA gene responsible for baloxavir resistance. All viruses tested by fluorescence assay were sensitive to oseltamivir and zanamivir. The worldwide frequency of influenza isolates resistant to antineuraminidase drugs does not exceed 1-2% of cases. Hence, oseltamivir and zanamivir provide effective treatment for seasonal influenza.

Severe Influenza-Associated Neurological Disease in Australian Children: Seasonal Population-Based Surveillance 2008-2018.

Influenza-associated neurological disease (IAND) is uncommon but can result in death or neurological morbidity in children. We aimed to describe the incidence, risk factors, and outcome of children with IAND from seasonal influenza in Australia. We analyzed national, population-based, surveillance data for children aged ≤ 14 years with severe influenza and neurological involvement, over 11 Australian influenza seasons, 2008-2018, by the Australian Paediatric Surveillance Unit. There were 633 laboratory-confirmed cases of severe influenza reported. Of these, 165 (26%) had IAND. The average annual incidence for IAND was 3.39 per million children aged ≤ 14 years. Compared to cases without neurological complications, those with IAND were more likely to have a pre-existing neurological disease (odds ratio [OR] 3.03, P < .001), but most children with IAND did not (n = 135, 82%). Children with IAND were more likely to receive antivirals (OR 1.80, P = .002), require intensive care (OR 1.79, P = .001), require ventilation (OR 1.99; P = .001), and die (OR 2.83, P = .004). IAND is a preventable cause of mortality, predominantly in otherwise well children. Incidence estimates validate previous sentinel site estimates from Australia. IAND accounted for a quarter of all severe influenza, is associated with intensive care unit admission, and accounted for half of all influenza deaths.

Clinical Pathway for Influenza in the Elderly: A comprehensive management protocol of Malaysia

Introduction: The clinical pathway (CP) is one of the most recommended tools for ensuring the best quality of care and has been proven to reduce the cost and time spent in hospital. The development of a CP for influenza is crucial, especially for the elderly, as they are vulnerable to influenza-related complications. The main aim of this study was to provide a comprehensive protocol for each component of influenza management among the elderly in Malaysia. Methods: An expert group meeting was conducted involving family medicine specialists, public health specialists, geriatricians, respiratory physicians and infectious disease physicians. The CP was designed following a 6-step protocol: 1) Selection of expert panel, 2) discussion and information gathering, 3) development of CP draft, 4) refinement of CP draft, 5) implementation of CP, and 6) finalisation of CP. The CP for influenza was designed based on service type and disease severity. Results: The panel described both outpatient and inpatient CPs for managing elderly patients with influenza. The outpatient CP covered mild and moderate influenza cases, while the inpatient CP addressed the management of moderate and severe influenza. The estimated length of hospital stay for moderate and severe influenza cases with pneumonia was 6 and 14 days, respectively. Conclusions: The CP for influenza supports existing treatment according to illness severity leveraged on current clinical practice guidelines and the best-care practices in primary and tertiary care settings. Continuous use of the CP is required to assess its effectiveness, thereby enabling optimisation of the healthcare process in influenza treatment.

Influenza antivirals and animal models.

Influenza A and B viruses are among the most prominent human respiratory pathogens. About 3–5 million severe cases of influenza are associated with 300 000–650 000 deaths per year globally. Antivirals effective at reducing morbidity and mortality are part of the first line of defense against influenza. FDA‐approved antiviral drugs currently include adamantanes (rimantadine and amantadine), neuraminidase inhibitors (NAI; peramivir, zanamivir, and oseltamivir), and the PA endonuclease inhibitor (baloxavir). Mutations associated with antiviral resistance are common and highlight the need for further improvement and development of novel anti‐influenza drugs. A summary is provided for the current knowledge of the approved influenza antivirals and antivirals strategies under evaluation in clinical trials. Preclinical evaluations of novel compounds effective against influenza in different animal models are also discussed.

SAPS 2 score valid parameter for outcome in severe influenza

The aim of study was to identify the significance of SAPS 2 score admission values on outcome in severe influenza. Materials and methods: The investigation was prospective, group comparison, con­duc­ted at the University Clinic for Infectious Diseases, Skopje in a three-year period. The study included adult patients with severe influenza divided in two groups, survived and deceased. Demographic, clinical and biochemical data were noted on admission. The variables of the univariate analysis that showed a significant difference in terms of the outcome were used for creating multivariate logistic and regression analysis of the outcome as dependent factors. The independent predictors for lethal outcome in severe cases of influenza were identified by using logistic regression. Results: The study included 87 patients with clinical and laboratory confirmed severe influenza divided in two groups: survived (n=75) and deceased (n=12). The overall mortality was 13.79%. Multivariate analysis conducted on admission identified SAPS II score (p=0.048) as independent predictor of the outcome in severe influenza. The increase of the SAPS II score in one point increased the chance of death in patients with influenza by 1.2% (OR=1.12 95% CI 1.01-2.976). Conclusion: In our study the SAPS II score has been identified as an independent va­riab­le, which has predicted the outcome in patients with severe influenza on hospital admission. The early identification of the outcome predictors in patients with severe influenza will ensure implementation of adequate medical procedures, and also, it will contribute to decreasing the mortality of this disease.

Cardiovascular complications in patients with severe pneumonia with influenza A/H1N1 / 09

Aim of the study was to analyze the frequency and nature of cardiovascular complications in influenza A/H1N1/09 in Zabaykalsky Krai from 2018 to 2019. Material and methods. 86 cases of severe influenza A/H1N1/09 were analyzed. Results. The patients were divided into 2 groups, comparable by gender and age. The first group consisted of patients with cardiovascular complications of influenza A/H1N1 / 09 (41 people). The second group consisted of patients without complicated flu (45 people). The average age of patients in the first group was 60 ± 13.7 years. According to the ECG results, sinus tachycardia with a heart rate of 94 ± 14.2 beats/min was dominant, in combination with various rhythm and conduction disorders: supraventricular extrasystole – in 5 (12 %) patients, acute (paroxysmal) atrial fibrillation – in 19 (46 %), ventricular extrasystole – in 7 (17 %), complete right and left bundle branch block – in 7 (17 %) and 7 (17 %), respectively, atrioventricular block of the 1st degree – in 1 (2 %) patients. Long QT syndrome was revealed in 5 patients (12 %). The severe cardiovascular system complications were: myopericarditis in 2 (5 %) people, decompensation of chronic heart failure in 4 (10 %) people, pulmonary embolism in 1 (2 %), acute myocardial infarction in 11 (27 %). The mortality rate in this group was 12 (29 %) cases from hospitalized patients. The average age of patients in the second group was 58 ± 14.1 years. According to the ECG results, sinus tachycardia with a heart rate of 91 ± 9.4 beats/min was detected in 98 % of cases, 3 (7 %) patients had complete left bundle branch block, 1 (2 %) patient had atrial fibrillation. No other rhythm or conduction disturbances were detected. No organic heart pathology was detected in this group of patients. The mortality rate was 5 (11 %) people. Conclusion. The analysis of 86 cases showed that elderly patients with a heavy premorbid background prevailed. The severe cardiovascular system complications were mainly represented by cardiac arrhythmias and the development of acute myocardial infarction. The fatal outcome occurred on the 8th-22nd day from the onset of the disease. The presence of cardiovascular complications doubles the mortality rate.

Letter to the Editor: Impact of COVID-19 Prevention Methods on Influenza and Other Respiratory Infections in Taiwan

Population Health ManagementVol. 24, No. 5 Letters to the EditorFree AccessLetter to the Editor: Impact of COVID-19 Prevention Methods on Influenza and Other Respiratory Infections in TaiwanDaniel L. Clinciu, Cheng-Hsien Chen, Jong-Yi Wang, and Garry HuangDaniel L. Clinciuhttps://orcid.org/0000-0001-5272-1414Department of Basic Medical Science, Graduate Institute of Biomedical Sciences, China Medical University, Taichung City, Taiwan.Search for more papers by this author, Cheng-Hsien ChenDepartment of Optics and Photonics, National Central University, Taoyuan City, Taiwan.*Correction added on August 3, 2021 after first online publication of July 14, 2021: The second author name has been corrected from Cheng-Shien Chen to Cheng-Hsien Chen.Search for more papers by this author, Jong-Yi WangDepartment of Health Services Administration, China Medical University, Taichung City, Taiwan.Search for more papers by this author, and Garry HuangAddress correspondence to: Garry Huang, PhD, Department of Health Care Administration, College of Management, Taipei Medical University, No. 250, Wuxing St., Xinyi District, Taipei City 110, Taiwan E-mail Address: garryhuang@tmu.edu.twhttps://orcid.org/0000-0002-1328-5055Department of Health Care Administration, College of Management, Taipei Medical University, Taipei City, Taiwan.Search for more papers by this authorPublished Online:18 Oct 2021https://doi.org/10.1089/pop.2021.0140AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail The mandatory wearing of face masks, hand sanitizing, and technology-aided quarantines have been in Taiwan since January 2020 to protect against spreading COVID-19.1,2 It is highly likely that COVID-19 prevention methods lowered the number of infections from various common respiratory infections. Therefore, we investigated the effect of the COVID-19 prevention methods on the incidence of other common respiratory infections.Using the Taiwan National Infectious Disease Statistics System, we analyzed the incidence of respiratory infectious diseases (eg, influenza season before and during the COVID-19 pandemic, December 2019–February 2021). We looked at trends of influenza, meningitis, and gastroenteritis in Taiwan before and during the COVID-19 pandemic to determine if Taiwan's efficient COVID-19 mandates (eg, wearing face masks in public places; hand sanitizing at the entrance of public transportation systems, supermarkets, schools, and other facilities; technology-aided quarantines) changed the trends of these common infectious diseases.3In week 52 of year 2020, almost a year after nationwide mandates for face masks, hand sanitation, and quarantines began, there were no confirmed cases of severe influenza in Taiwan. Notably, on week 2 of 2020, before COVID-19 mandates went into effect, there were 109 confirmed severe cases at the height of the influenza season. There also were 5 cases of confirmed severe viral gastroenteritis, as opposed to only 1 confirmed severe case after preventive measures were implemented. Additionally, there were 2 cases of confirmed severe meningococcal meningitis before February 2020 compared to 0 cases from February 2020 through March 2021.The Taiwan National Infectious Disease Statistics System only records severe/complicated cases of infectious diseases; thus, many cases of mild influenza and/or other unrecorded infectious diseases that likely were prevented by mandatory face masks, hand sanitation, and quarantines were not recorded. Some countries may have experienced similar trends for common respiratory infections as Taiwan. Arguably, in other countries, reduced cases of common infections also could be attributed to more people staying home because of lockdowns, and fear of COVID-19. However, Taiwan implemented no lockdowns and there was no indication that more people in Taiwan stayed home during the pandemic, as trains and buses often operated at maximum capacity and people are seen outdoors in large numbers. The reduced number of influenza infections and other infectious diseases meant decreasing health care costs and reducing the burden on the health care system.Taiwan's example could influence and benefit other nations that, prior to the COVID-19 pandemic, did not value the benefits of face masks during influenza season, with many places and people even now stigmatized or showing skepticism over wearing face masks in public.4 Although it seems reasonable that poorer nations initially could not afford to provide masks for everyone in the country, it is clear that the cost of face masks is lower by far than the costs of providing ventilators and other medical technologies as a result of COVID-19, influenza, and other infectious diseases. Overall, the COVID-19 pandemic may have uncovered many important aspects for health care systems worldwide and population health management, especially influenza infections and other common respiratory infections.Author Disclosure StatementThe authors declare that there are no conflicts of interest.Funding InformationNo funding was received for this letter.

Behavior of hospitalized severe influenza cases according to the outcome variable in Catalonia, Spain, during the 2017\u20132018 season

Influenza is an important cause of severe illness and death among patients with underlying medical conditions and in the elderly. The aim of this study was to investigate factors associated with ICU admission and death in patients hospitalized with severe laboratory-confirmed influenza during the 2017–2018 season in Catalonia. An observational epidemiological case-to-case study was carried out. Reported cases of severe laboratory-confirmed influenza requiring hospitalization in 2017–2018 influenza season were included. Mixed-effects regression analysis was used to estimate the factors associated with ICU admission and death. A total of 1306 cases of hospitalized severe influenza cases were included, of whom 175 (13.4%) died and 217 (16.6%) were ICU admitted. Age 65–74 years and ≥ 75 years and having ≥ 2 comorbidities were positively associated with death (aOR 3.19; 95%CI 1.19–8.50, aOR 6.95, 95%CI 2.76–1.80 and aOR 1.99; 95%CI 1.12–3.52, respectively). Neuraminidase inhibitor treatment and pneumonia were negatively associated with death. The 65–74 years and ≥ 75 years age groups were negatively associated with ICU admission (aOR 0.41; 95%CI 0.23–0.74 and aOR 0.30; 95%CI 0.17–0.53, respectively). A factor positively associated with ICU admission was neuraminidase inhibitor treatment. Our results support the need to investigate the worst outcomes of hospitalized severe cases, distinguishing between death and ICU admission.

Black in Immuno ‐ amplifying, celebrating, and supporting Black voices in immunology

Black in Immuno ‐ amplifying, celebrating, and supporting Black voices in immunology

Molecular Characterization of Seasonal Influenza A and B from Hospitalized Patients in Thailand in 2018-2019.

Influenza viruses continue to be a major public health threat due to the possible emergence of more virulent influenza virus strains resulting from dynamic changes in virus adaptability, consequent of functional mutations and antigenic drift in surface proteins, especially hemagglutinin (HA) and neuraminidase (NA). In this study, we describe the genetic and evolutionary characteristics of H1N1, H3N2, and influenza B strains detected in severe cases of seasonal influenza in Thailand from 2018 to 2019. We genetically characterized seven A/H1N1 isolates, seven A/H3N2 isolates, and six influenza B isolates. Five of the seven A/H1N1 viruses were found to belong to clade 6B.1 and were antigenically similar to A/Switzerland/3330/2017 (H1N1), whereas two isolates belonged to clade 6B.1A1 and clustered with A/Brisbane/02/2018 (H1N1). Interestingly, we observed additional mutations at antigenic sites (S91R, S181T, T202I) as well as a unique mutation at a receptor binding site (S200P). Three-dimensional (3D) protein structure analysis of hemagglutinin protein reveals that this unique mutation may lead to the altered binding of the HA protein to a sialic acid receptor. A/H3N2 isolates were found to belong to clade 3C.2a2 and 3C.2a1b, clustering with A/Switzerland/8060/2017 (H3N2) and A/South Australia/34/2019 (H3N2), respectively. Amino acid sequence analysis revealed 10 mutations at antigenic sites including T144A/I, T151K, Q213R, S214P, T176K, D69N, Q277R, N137K, N187K, and E78K/G. All influenza B isolates in this study belong to the Victoria lineage. Five out of six isolates belong to clade 1A3-DEL, which relate closely to B/Washington/02/2009, with one isolate lacking the three amino acid deletion on the HA segment at position K162, N163, and D164. In comparison to the B/Colorado/06/2017, which is the representative of influenza B Victoria lineage vaccine strain, these substitutions include G129D, G133R, K136E, and V180R for HA protein. Importantly, the susceptibility to oseltamivir of influenza B isolates, but not A/H1N1 and A/H3N2 isolates, were reduced as assessed by the phenotypic assay. This study demonstrates the importance of monitoring genetic variation in influenza viruses regarding how acquired mutations could be associated with an improved adaptability for efficient transmission.

Expression of Surfactant Protein D Distinguishes Severe Pandemic Influenza A(H1N1) from Coronavirus Disease 2019.

The differentiation between influenza and coronavirus disease 2019 (COVID-19) could constitute a diagnostic challenge during the ongoing winter owing to their clinical similitude. Thus, novel biomarkers are required to enable making this distinction. Here, we evaluated whether the surfactant protein D (SP-D), a collectin produced at the alveolar epithelium with known immune properties, was useful to differentiate pandemic influenza A(H1N1) from COVID-19 in critically ill patients. Our results revealed high serum SP-D levels in patients with severe pandemic influenza but not those with COVID-19. This finding was validated in a separate cohort of mechanically ventilated patients with COVID-19 who also showed low plasma SP-D levels. However, plasma SP-D levels did not distinguish seasonal influenza from COVID-19 in mild-to-moderate disease. Finally, we found that high serum SP-D levels were associated with death and renal failure among severe pandemic influenza cases. Thus, our studies have identified SP-D as a unique biomarker expressed during severe pandemic influenza but not COVID-19.