Genome characterization of influenza A and B viruses in New South Wales, Australia, in 2019: A retrospective study using high-throughput whole genome sequencing.

BACKGROUND: During the 2019 severe influenza season, New South Wales (NSW) experienced the highest number of cases in Australia. This study retrospectively investigated the genetic characteristics of influenza viruses circulating in NSW in 2019 and identified genetic markers related to antiviral resistance and potential virulence. METHODS: The complete genomes of influenza A and B viruses were amplified using reverse transcription-polymerase chain reaction (PCR) and sequenced with an Illumina MiSeq platform. RESULTS: When comparing the sequencing data with the vaccine strains and reference sequences, the phylogenetic analysis revealed that most NSW A/H3N2 viruses (n = 68; 94%) belonged to 3C.2a1b and a minority (n = 4; 6%) belonged to 3C.3a. These viruses all diverged from the vaccine strain A/Switzerland/8060/2017. All A/H1N1pdm09 viruses (n = 20) showed genetic dissimilarity from vaccine strain A/Michigan/45/2015, with subclades 6B.1A.5 and 6B.1A.2 identified. All B/Victoria-lineage viruses (n = 21) aligned with clade V1A.3, presenting triple amino acid deletions at positions 162-164 in the hemagglutinin protein, significantly diverging from the vaccine strain B/Colorado/06/2017. Multiple amino acid substitutions were also found in the internal proteins of influenza viruses, some of which have been previously reported in hospitalized influenza patients in Thailand. Notably, the oseltamivir-resistant marker H275Y was present in one immunocompromised patient infected with A/H1N1pdm09 and the resistance-related mutation I222V was detected in another A/H3N2-infected patient. CONCLUSIONS: Considering antigenic drift and the constant evolution of circulating A and B strains, we believe continuous monitoring of influenza viruses in NSW via the high-throughput sequencing approach provides timely and pivotal information for both public health surveillance and clinical treatment.

Covid-19 and influenza vaccine effectiveness against associated hospital admission and death among individuals over 65 years in Norway: A population-based cohort study, 3 October 2022 to 20 June 2023.

BACKGROUND: Co-circulation of SARS-CoV-2 and influenza virus can lead to double epidemics and increased pressure on health systems. To evaluate the effect of both vaccines, we estimated the adjusted vaccine effectiveness (aVE) of influenza and Covid-19 vaccines against related severe disease in the elderly population in Norway during the 2022/2023 season. METHODS: In this population-based cohort study, we included data from the Emergency preparedness register for Covid-19 (Beredt C19) on all individuals ≥ 65 years living in Norway between 3 October 2022 and 20 June 2023. Using Cox-proportional hazard models, we estimated aVE of both influenza and Covid-19 vaccines (bivalent BA.1 and BA.4-5) against associated hospitalisation and death. Vaccine status was included as a time-varying covariate and all models were adjusted for potential confounders, including the other vaccine. RESULTS: We identified 2,437 influenza-associated hospitalisations and 178 deaths, alongside 5,824 Covid-19-associated hospitalisations and 621 deaths. The aVE was highest in the first three months after receiving either vaccine. Against influenza-associated hospitalisation the aVE was 34 % (26 %-42 %) among 65-79-year-olds and 40 % (30 %-48 %) among ≥ 80-year-olds, and 6.6 % (-64 %-47 %) and 37 % (0.5 %-61 %) against influenza-associated death, respectively. The aVE against Covid-19-associated hospitalisation was 65 % (61 %-69 %) among 65-79-year-olds and 55 % (49 %-60 %) among ≥ 80-year-olds (compared to having received the vaccine ≥ 180 days ago). Similarly, the aVE against Covid-19-associated death was 68 % (48 %-80 %) and 78 % (65 %-86 %), respectively. For Covid-19 we show a reduction in aVE with time since dose. CONCLUSION: Covid-19 and influenza vaccines reduced the risk of severe disease in the same high-risk population. Ensuring high uptake of both vaccines could thus limit the overall health care burden.

Comparing COVID-19 and influenza: Epidemiology, clinical characteristics, outcomes and mortality in the ICU.

RATIONALE: Several authors have compared COVID-19 infection with influenza in the ICU. OBJECTIVE: This study aimed to compare the baseline clinical profiles, care procedures, and mortality outcomes of patients admitted to the intensive care unit, categorized by infection status (Influenza vs. COVID-19). METHODS: Retrospective observational study. Data were extracted from the Toulouse University Hospital from March 2014 to March 2021. To compare survival curves, we plotted the survival at Day-90 using the Kaplan-Meier curve and conducted a log-rank test. Additionally, we performed propensity score matching to adjust for confounding factors between the COVID-19 and influenza groups. Furthermore, we use the CART model for multivariate analysis. RESULTS: The study included 363 patients admitted to the ICU due to severe viral pneumonia: 152 patients (41.9 %) with influenza and 211 patients (58.1 %) with COVID-19. COVID-19 patients exhibited a higher prevalence of cardiovascular risk factors, whereas influenza patients had significantly higher severity scores (SOFA: 10 [6-12] vs. 6 [3-9], p<0.01 and SAPS II: 51 [35-67] vs. 37 [29-50], p<0.001). Overall mortality rates were comparable between the two groups (27.6 % (n = 42) in the influenza group vs. 21.8 % (n = 46) in the COVID-19 group, p=NS). Mechanical ventilation was more commonly employed in the influenza group (76.3 % (n = 116) vs. 59.7 % (n = 126), p<0.001); however, COVID-19 patients required longer durations of mechanical ventilation (18 [9-29] days vs. 13 [5-24] days, p<0.006) and longer hospital stays (23 [13-34] days vs. 18.5 [9-34.5] days, p = 0.009). The CART analysis revealed that the use of extra renal replacement therapy was the most influential prognostic factor in the influenza group, while the PaO2/FiO2-PEEP ratio played a significant role in the COVID-19 group. CONCLUSIONS: Despite differences in clinical presentation and prognostic factors, the mortality rates at 90 days, after adjusting for confounding factors, were similar between COVID-19 and influenza patients.

Impact of influenza immunity on the mortality among older adults hospitalized with COVID-19: a retrospective cohort study.

It has been suggested that the outcomes of coronavirus disease 2019 (COVID-19) are better in individuals having recently received an influenza vaccine than in non-vaccinated individuals. We hypothesized that this association depends on the humoral responses against influenza viruses. We aim to assess the relationship between the humoral immunity against influenza and the 3-month all-cause mortality among hospitalized older patients with COVID-19. We performed an exploratory retrospective study of older patients (aged 65 and over) hospitalized for confirmed COVID-19 between November 2020 and June 2021. Previous humoral responses to influenza viruses were assessed using a hemagglutination inhibition assay on routinely collected blood samples. The study's primary outcome was the 3-month all-cause mortality, and the secondary outcomes were severe COVID-19 (oxygen requirement ≥ 6 L/min or ventilatory support) and complications (kidney or heart failure, thrombosis and bacterial infection). In the cohort of 95 patients with COVID-19, immunity against influenza vaccine subtypes/lineages was not significantly associated with 3-month all-cause mortality, with an OR [95%CI] of 0.22 [0.02-1.95] (p = 0.174) for the H1N1pdm09 subtype, 0.21 [0.03-1.24] (p = 0.081) for A/Hong Kong/2671/2019 H3N2 subtype, 1.98 [0.51-8.24] (p = 0.329) for the B/Victoria lineage, and 1.82 [0.40-8.45] (p = 0.437) for the B/Yamagata lineage. Immunity against influenza vaccine subtypes/lineages was also not significantly associated with severity and complication. Immunity against influenza subtypes/lineages included in the 2020-2021 vaccine was not associated with a lower 3-month all-cause mortality among COVID-19 hospitalized patients.Trial registration: The study was approved by a hospital committee with competency for research not requiring approval by an institutional review board (Tours University Medical Center, Tours, France: reference: 2021_015). All patients give the informed consent.

Sex differences in adverse events following seasonal influenza vaccines: a meta-analysis of randomised controlled trials.

BACKGROUND: Despite being a vaccine-preventable disease, influenza remains a major public health threat with vaccine safety concerns reducing vaccine acceptability. Immune responses to vaccines and adverse events may differ between males and females, but most studies do not report results by sex. Using data from clinical trials, we explored sex differences in adverse events following seasonal influenza vaccines. METHODS: We obtained data for phase III randomised controlled trials identified through a systematic review and clinical trials registries, and performed a two-stage meta-analysis. Risk ratios (RR) and 95% confidence intervals (95% CI) comparing solicited reactions in females versus males were pooled using the Mantel-Haenszel method and a random-effects model. We used the ROBINS-I tool to assess risk of bias and the I2 statistic for heterogeneity. Main analysis was stratified by age: 18-64 years and ≥65 years. RESULTS: The dataset for this analysis included 34 343 adults from 18 studies (12 with individual-level data and 6 with aggregate data). There was a higher risk of injection site reactions in females compared with males for both younger and older participants, with RRs of 1.29 (95% CI 1.21 to 1.37) and 1.43 (95% CI 1.28 to 1.60), respectively. Higher risk in females was also observed for systemic reactions, with RRs of 1.25 (95% CI 1.20 to 1.31) and 1.27 (95% CI 1.20 to 1.34) for younger and older participants, respectively. We also observed elevated risks of severe reactions in females, with a higher RR in younger versus older participants for systemic reactions (RRs 2.12 and 1.48, p=0.03, I2=79.7%). RRs were not found to vary between quadrivalent and trivalent vaccines. CONCLUSION: This meta-analysis suggested a higher risk of solicited reactions following influenza vaccines for females compared with males, irrespective of age and vaccine type. Transparent communication of this risk could increase the trust in vaccines and limit vaccine hesitancy. Future studies should report results stratified by sex and explore the role of gender in the occurrence of adverse events.

Evaluating the performance of WHO and CDC case definitions for influenza-like illness in diagnosing influenza during the 2022-2023 flu season in Mexico.

OBJECTIVE: This study aimed to evaluate the performance of the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) case definitions for influenza-like illness (ILI) in diagnosing influenza during the 2022-2023 flu season in Mexico. STUDY DESIGN: We conducted a cross-sectional analysis of national epidemiological surveillance data in Mexico, focusing on respiratory viral pathogens. METHODS: We analyzed data from 6027 non-hospitalized patients between 5 and 65 years old who underwent molecular testing for respiratory viral pathogens. The performance of both case definitions was evaluated in terms of sensitivity, specificity, and the area under the receiver operating characteristic (AUROC) curve. RESULTS: Overall, the diagnostic accuracy of the evaluated ILI definitions in identifying influenza patients was low, particularly among older patients. When compared to the CDC, the WHO definition had a lower sensitivity but a higher specificity, resulting in a higher AUROC (P = 0.031) for the WHO criteria. CONCLUSIONS: Our findings suggest that the WHO and CDC ILI case definitions have limited accuracy for diagnosing influenza in non-hospitalized patients and highlight the need for more specific diagnostic tools to improve the detection of influenza cases during the flu season.

Low uptake of seasonal influenza vaccination in Al-Jouf region of Saudi Arabia.

Introduction: Seasonal influenza is a contagious viral respiratory condition typically occurring in the fall to early spring months of the year globally. The risk of infection from seasonal influenza can be greatly reduced with vaccination. Unfortunately, research has indicated that the seasonal influenza vaccination rate in Saudi Arabia is low. This study assessed the uptake of seasonal influenza vaccination among adults residing in Al-Jouf region, Saudi Arabia. Materials and Methods: A cross-sectional survey targeting adults (20-80 years) residing in Al-Jouf region, Saudi Arabia, was conducted to gather information about their sociodemographic characteristics, chronic conditions, knowledge about periodic health examinations (PHE), regular use of PHE, and uptake of seasonal influenza vaccination. Comparative statistics and a multivariate logistic regression analysis were conducted to determine characteristics associated with the uptake of seasonal influenza vaccination. Results: A total of 624 respondents completed the survey and participated in this study. Among the participants, 27.4% indicated they visited their primary healthcare centers or hospitals every year to get a seasonal influenza vaccination. The regression analysis showed that the odds of getting a seasonal influenza vaccination were higher among employed respondents (Odds Ratio [OR] = 1.73; P = 0.039), respondents who were employees of the healthcare sector (OR = 2.31; P = 0.001), and those with a higher PHE Knowledge Score (OR = 1.22; P = 0.008), compared to their counterparts. Conclusions: Seasonal influenza is a serious condition warranting appropriate prevention measures, including vaccination. However, this study confirmed low rates of seasonal influenza vaccination in Al-Jouf Region of Saudi Arabia. Interventions to boost vaccination uptake, in particular among unemployed individuals, those not working in the healthcare sector, and those with lower PHE knowledge Scores, are therefore recommended.

Prevalence of chronic conditions and influenza vaccination coverage rates in Germany: Results of a health insurance claims data analysis.

BACKGROUND: The significant annual burden caused by seasonal influenza has led to global calls for increased influenza vaccination coverage rates (VCRs). We aimed to estimate the proportion of the German population at high risk of serious illness from influenza due to chronic conditions and to estimate age-specific VCRs of people with/without chronic conditions. METHODS: Using health insurance claims data covering nine influenza seasons (2010-2019), we assessed up to 7 million insured individuals per season across all German regions. Individuals were classified according to age and presence of chronic health conditions. VCRs were estimated using outpatient healthcare utilization documentation. RESULTS: In the 2018-2019 influenza season, 47.3% of individuals had ≥1 chronic condition. Most common were circulatory disorders, accounting for more than a third of individuals with ≥1 condition. Prevalence of chronic diseases, and therefore the proportion of high-risk individuals, increased slightly over time across most age groups. A downward trend in influenza VCRs was observed in all age groups until the 2017-2018 season, followed by a noticeable increase in the 2018-2019 season. Highest VCRs occurred among individuals of ≥60 years, with a 38.5% VCR for this age group in the 2018-2019 season. Several factors, including age, chronic condition type, and geographical location, affected VCRs. CONCLUSIONS: Influenza VCRs in individuals at high risk of severe complications from influenza infection are insufficient. Our results suggest that intensified public health efforts are necessary to reach the World Health Organization vaccination coverage target of 75%.

An outbreak of school influenza complicated with mycoplasma pneumoniae infection / 中国学校卫生

Objective@#To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai.@*Methods@#Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing.@*Results@#A total of 16 influenza like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59% (15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone( P <0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled.@*Conclusion@#This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

Ethical considerations on placebo-controlled vaccine trials in pregnant women / Consideraciones éticas sobre los ensayos de vacunas controlados con placebo en mujeres embarazadas / Considerações éticas sobre estudos de vacina controlada com placebo em gestantes

Abstract Placebo use in clinical trials, whenever a proven effective treatment exists, is one of the most debated topics in contemporary research ethics. This article addresses the ethical framework for placebo use in clinical trials assessing vaccine efficacy in pregnant women. Vaccine trial participants are healthy at the outset and some must be infected during the study to demonstrate the product's efficacy, meaning that placebo-treated participants are under risk of serious and irreversible harm. If effective vaccines exist, such risk precludes placebo use. This interdiction should be extended to any clinical trial of vaccine efficacy in pregnant women, because a demonstration of clinical efficacy in nonpregnant individuals and comparable immunogenic responses in pregnant women are predictors of efficacy in pregnancy as well. Moreover, product effectiveness in real-world use scenarios can be ascertained by observational studies conducted after its inclusion in vaccination campaigns.

Resumen El uso de placebo en ensayos clínicos es uno de los principales temas debatidos sobre la ética en investigación contemporánea cuando existe un tratamiento eficaz probado. Este artículo aborda la ética en el uso de placebo en ensayos clínicos sobre la eficacia de vacuna en mujeres embarazadas. Las participantes en los ensayos de vacunas estaban sanas al inicio del estudio, y algunas fueron vacunadas durante el estudio para demostrar la eficacia del producto. Las participantes tratadas con placebo corren el riesgo de sufrir daños graves e irreversibles. Si existen vacunas efectivas, este riesgo impide el uso de placebo. Este impedimento debe extenderse a cualquier ensayo clínico de eficacia de vacuna en embarazadas, pues la eficacia clínica demostrada en mujeres no embarazadas y las respuestas inmunogénicas comparables con las embarazadas son predictores de eficacia en el embarazo. Además, la efectividad del producto se constata en estudios observacionales realizados tras las campañas de vacunación.

Resumo O uso de placebo em ensaios clínicos, quando um tratamento comprovadamente eficaz existe, é um dos principais tópicos debatidos na ética em pesquisa contemporânea. Este artigo aborda o quadro ético para o uso de placebo em ensaios clínicos que avaliam a eficácia de vacina em gestantes. Participantes em ensaios de vacina são saudáveis no início e alguns devem ser inoculados durante o estudo para demonstrar a eficácia do produto. Ou seja, participantes tratados com placebo estão sob risco de danos graves e irreversíveis. Se existirem vacinas eficazes, esse risco impede o uso de placebo. Essa interdição deve ser estendida a qualquer ensaio clínico de eficácia de vacina em gestantes, pois a demonstração de eficácia clínica em não gestantes e as respostas imunogênicas comparáveis em gestantes também são preditoras de eficácia na gravidez. Ademais, a eficácia do produto em cenários reais de uso pode ser verificada por estudos observacionais realizados após sua inclusão em campanhas de vacinação.

Analysis of an outbreak of influenza A in a primary school in Jing an District, Shanghai / 中国学校卫生

Objective@#To investigate the epidemiological data of an outbreak of influenza A in a primary school in Shanghai, to provide reference for targeted prevention and control measures.@*Methods@#A field epidemiological method was used to investigate and collect the data of influenza A outbreak in a primary school in Jing an District from November 8 to December 6, 2022, through on site follow up and telephone return visit to health teachers and cases. The distribution characteristics of the epidemic were analyzed by descriptive epidemiology.@*Results@#The first case developed symptoms of cough, sore throat, and fever on the morning of November 8th 2022, with a maximum body temperature of 38.6 ℃. Later, the clinical diagnosis was influenza A. The total number of influenza like cases reported in this outbreak is 99, including 92 students and 7 teachers. The total incidence rate was 9.45%. The clinical symptoms of all cases were fever, sore throat, and cough; 27 cases of influenza A were diagnosed by hospital rapid diagnostic reagents. The second grade students had the highest case incidence rate(24.46%), and there was a statistically significant difference in case incidence rates among students of different grades ( χ 2=48.28, P ＜0.01). The case incidence rate on the second floor was the highest (23.47%), and there was a statistically significant difference between the case incidence rates on different floors ( χ 2=52.38, P ＜ 0.01 ). Etiological testing showed that the influenza virus causing this outbreak was type A H3N2 virus.@*Conclusion@#This outbreak is a campus cluster outbreak caused by influenza A (H3N2) virus. The health and education departments should strengthen cooperation to effectively implement prevention and control measures of infectious diseases, and timely identify the source of infection and cut off the transmission route.

Special considerations for influenza in the elderly / 中华老年医学杂志

Influenza is a common disease that affects the population in many ways.When the elderly contract influenza, they are prone to complications, leading to severe illness and even death.Influenza has serious consequences to the health of older people.Identification and prevention of influenza in the elderly are of critical importance.This paper summarizes certain distinctive features of influenza in the elderly.

The impact of repeated vaccination on relative influenza vaccine effectiveness among vaccinated adults in the United Kingdom.

Annual seasonal influenza vaccination is recommended for individuals at high risk of developing post-infection complications in many locations. However, reduced vaccine immunogenicity and effectiveness have been observed among repeat vaccinees in some influenza seasons. We investigated the impact of repeated influenza vaccination on relative vaccine effectiveness (VE) among individuals who were recommended for influenza vaccination in the United Kingdom with a retrospective cohort study using primary healthcare data from the Clinical Practice Research Datalink, a primary care database in the United Kingdom. Relative VE was estimated against general practitioner-diagnosed influenza-like illnesses (GP-ILI) and medically attended acute respiratory illnesses (MAARI) among participants who have been repeatedly vaccinated compared with first-time vaccinees using proportional hazards models. Relative VE against MAARI may be reduced for individuals above 65 years old who were vaccinated in the current and previous influenza seasons for some influenza seasons. However, these findings were not conclusive as we could not exclude the possibility of residual confounding in our dataset. The use of routinely collected data from electronic health records to examine the effects of repeated vaccination needs to be complemented with sufficient efforts to include negative control outcomes to rule out residual confounding.

Comparing antibiotic prescriptions in primary care between SARS-CoV-2 and influenza: a retrospective observational study.

BACKGROUND: Antibiotics are frequently prescribed during viral respiratory infection episodes in primary care. There is limited information about antibiotic prescription during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in primary care and its association with risk factors for an adverse course. AIM: To compare the proportion of antibiotic prescriptions between patients with COVID-19 and influenza or influenza-like symptoms, and to assess the association between antibiotic prescriptions and risk factors for an adverse course of COVID-19. DESIGN & SETTING: An observational cohort study using pseudonymised and coded routine healthcare data extracted from 85 primary care practices in the Netherlands. METHOD: Adult patients with influenza and influenza-like symptoms were included from the 2017 influenza season to the 2020 season. Adult patients with suspected or confirmed COVID-19 were included from the first (15 February 2020-1 August 2020) and second (1 August 2020-1 January 2021) SARS-CoV-2 waves. Proportions of antibiotic prescriptions were calculated for influenza and COVID-19 patients. Odds ratios (ORs) were used to compare the associations of antibiotic prescriptions in COVID-19 patients with risk factors, hospital admission, intensive care unit (ICU) admission, and mortality. RESULTS: The proportion of antibiotic prescriptions during the first SARS-CoV-2 wave was lower than during the 2020 influenza season (9.6% versus 20.7%), difference 11.1% (95% confidence interval [CI] = 8.7 to 13.5). During the second SARS-CoV-2 wave, antibiotic prescriptions were associated with being aged ≥70 years (OR 2.05; 95% CI = 1.43 to 2.93), the number of comorbidities (OR 1.46; 95% CI = 1.18 to 1.82), and admission to hospital (OR 3.19; 95% CI = 2.02 to 5.03) or ICU (OR 4.64; 95% CI = 2.02 to 10.62). CONCLUSION: Antibiotic prescription was less common during the SARS-CoV-2 pandemic than during influenza seasons, and was associated with an adverse course and its risk factors. The findings suggest a relatively targeted prescription policy of antibiotics in primary care during COVID-19.

A Population-Based Susceptible, Infected, Recovered Simulation Model of the Spread of Influenza-Like-Illness in the Homeless versus Non-Homeless Population.

PURPOSE: To examine the prevalence and characteristics of influenza-like illness (ILI) related presentations among people experiencing homelessness compared to the general population as well as to use the Susceptible, Infected, Recovered (SIR) simulation model parameters ß and γ to model infectious interactivity, recovery rate, and population-level basic reproduction number (R0). METHODS: Using administrative health data from emergency department (ED) visits in the province of Ontario, Canada from 2010 to 2017, an SIR model was used to calculate the R0 for ILI in both the general population and the population of homeless individuals. RESULTS: From 2010 to 2017, a total of 17,056 homeless and 85,553 non-homeless individuals presented with an ILI to an ED in Ontario. The estimated infectious interactivity (ß) was lower while the recovery rate (γ) was longer for infected people experiencing homelessness. CONCLUSIONS: Our results suggest that infections of ILI will result in more secondary cases in the homeless population compared to the homed population. This evaluation of the dynamics of ILI spread in the homeless population provides insight into how illnesses such as COVID-19 may be much more infectious in this population compared to the homed population.

Scientific publication speed and retractions of COVID-19 pandemic original articles.

Objective: To describe the editorial processing time of published COVID-19 research articles and compare this with a similar topic, human influenza, and analyze the number of publications, withdrawals, and retractions. Methods: A descriptive-analytical study using PubMed on research articles with the MeSH terms human influenza and COVID-19. Time to acceptance (from submission to acceptance) and time to publication (from acceptance to publication) were compared. Retractions and withdrawals were reviewed both qualitatively and quantitatively. Results: There were 31 319 research articles on COVID-19 and 4 287 on human influenza published during 2020. The median time to acceptance for COVID-19 was lower than that for human influenza (8 vs. 92 days). The median time to publication for COVID-19 articles was shorter than those on human influenza (12 vs. 16 days); 47.0% of COVID-19 research articles were accepted within the first week of submission, and 19.5% within one day. There were 82 retractions and withdrawals for COVID-19 articles, 1 for human influenza, and 5 for articles that contain both terms; these were mainly related to ethical misconduct, and 27 (31.0%) were published by the same group of authors in one highest-quartile journal. Conclusions: The conundrum between fast publishing and adequate standards is shown in this analysis of COVID-19 research articles. The speed of acceptance for COVID-19 manuscripts was 11.5 times faster than for human influenza. The high number of acceptances within a day or week of submission and the number of retractions and withdrawals of COVID-19 papers might be a warning sign about the possible lack of a quality control process in scientific publishing and the peer review process.

[Clinical characteristics of influenza pneumonia in the elderly and relationship between D-dimer and disease severity].

OBJECTIVE: To clarify the clinical characteristics of influenza pneumonia in the elderly patients and the relationship between D-dimer and the severity of influenza pneumonia. METHODS: In the study, 52 hospitalized patients older than 65 years with confirmed influenza pneumonia diagnosed in Peking University People's Hospital on 5 consecutive influenza seasons from 2014 were retrospectively analyzed. General information, clinical symptoms, laboratory data, treatment methods and prognosis of the patients were collected. The relationship between D-dimer and pneumonia severity was analyzed, and receiver operating characteristic (ROC) curve was used to evaluate the predictive value of D-dimer. RESULTS: Among the 52 patients, 31 were male (31/52, 59.6%), the average age was (77.1±7.4) years, and 19 of them (36.5%) were diagnosed with severe pneumonia. About 70% patients presenting with fever. In the severe group, the patients were more likely to complain of dyspnea than in the non-severe group (14/19, 73.7% vs. 10/33, 30.3%, P=0.004), severe pneumonia group had higher level of CURB-65 (confusion, urea, respiratory rate, blood pressure, and age>65), pneumonia severity index (PSI), C-reactive protein, urea nitrogen, lactate dehydrogenase, fasting glucose, and D-dimer (P value was 0.004, < 0.001, < 0.001, 0.003, 0.038, 0.018, and < 0.001, respectively), albumin was lower than that in the non-severe group [(35.8±5.6) g/L vs. (38.9±3.5) g/L, t=-2.348, P=0.018]. There was a significant positive correlation between the D-dimer at the first admission and PSI score (r=0.540, 95%CI: 0.302 to 0.714, P < 0.001), while a significant negative correlation with PaO2/FiO2 (r=-0.559, 95%CI: -0.726 to -0.330, P < 0.001). Area under the curve of D-dimer was 0.765 (95%CI: 0.627 to 0.872). Area under the curve of PSI was 0.843 (95%CI: 0.716 to 0.929). There was no statistically significant difference in test efficacy between the two (Z=2.360, P=0.174). D-dimer level over 1 225 µg/L had a positive predict value for influenza pneumonia in hospital death with a sensitivity of 76.92% and a specificity of 74.36%. CONCLUSION: Influenza pneumonia in the elderly always has atypical symptoms, dyspnea is a prominent feature in severe cases, D-dimer level is associated with the severity of influenza pneumonia, and greater than 1 200 µg/L has a good predictive value for in-hospital death in the elderly.