Cases Of Influenza Research Articles

Influenza Vaccination, Household Composition, and Race-Based Differences in Influenza Incidence: An Agent-Based Modeling Study.

Objectives. To estimate the effect of influenza vaccination disparities. Methods. We compared symptomatic influenza cases between Black and White races in 2 scenarios: (1) race- and age-specific vaccination coverage and (2) equal vaccination coverage. We also compared differences in household composition between races. We used the Framework for Reconstructing Epidemiological Dynamics, an agent-based model that assigns US Census‒based age, race, households, and geographic location to agents (individual people), in US counties of varying racial and age composition. Results. Influenza cases were highest in counties with higher proportions of children. Cases were up to 30% higher in Black agents with both race-based and race-equal vaccination coverage. Compared with corresponding categories of White households, cases in Black households without children were lower and with children were higher. Conclusions. Racial disparities in influenza cases persisted after equalizing vaccination coverage. The proportion of children in the population contributed to the number of influenza cases regardless of race. Differences in household composition may provide insight into racial differences and offer an opportunity to improve vaccination coverage to reduce influenza burden for both races. (Am J Public Health. Published online ahead of print November 14, 2024:e1-e8. https://doi.org/10.2105/AJPH.2024.307878).

Abstract 4123849: Respiratory Syncytial Virus (RSV) Cases Involving Hospitalization Are Associated with an Increased Risk of Myocardial Infarction and All−Cause Mortality Among Adults Aged 50 Years and Older

Background: Older adults and adults with comorbidities are at increased risk for severe respiratory syncytial virus (RSV) disease and related complications. Aims: To estimate the risk of myocardial infarction (MI) and all−cause mortality among adults aged ≥50 years hospitalized with RSV compared to those with no recent acute respiratory illness (ARI) and those hospitalized with influenza. Methods: Data from Optum’s de−identified Clinformatics® Data Mart Database were analyzed (October 2015–June 2023) in this retrospective cohort study. Adults aged ≥50 years with ≥12 months of continuous enrollment were assigned to cohorts based on RSV or influenza hospitalization (from ICD−10 codes; RSV and flu cohorts) or no recent ARI (control cohort). Index dates for RSV and flu cohorts were the start of an ARI that included hospitalization. Baseline characteristics were measured in the 12 months pre−index. MI (from ICD−10 codes) and all−cause mortality were measured during follow−up and compared between cohorts using time−varying coefficient multivariable adjusted Cox models (MI results accounted for the competing risk of death). Results: In the RSV cohort (n=14,759), mean age (76.5 years) and mean Charlson comorbidity index (CCI; 3.3) were higher than the flu (n=77,468; 75.4 years, CCI=2.9) and control (n=73,795; 69.5 years, CCI=1.0) cohorts. Adjusted HRs (95% CI) for MI and all−cause mortality risk were significantly higher in the RSV vs control cohort across follow−up, ranging from 30.96 (26.22–36.54) within 30 days post−index to 2.26 (2.04–2.51) >365 days post−index for MI and 10.77 (9.19–12.63) within 30 days post−index to 2.29 (2.18–2.42) >365 days post−index for mortality. Compared to the flu cohort, adjusted MI and mortality risk in the RSV cohort were lower during the 30 days post−index (MI: 0.87 [0.82–0.92]; mortality: 0.84 [0.78–0.90]) but higher >365 days post−index (MI: 1.11 [1.01–1.22]; mortality: 1.05 [1.01–1.10]). Conclusion: MI and all−cause mortality risk were higher for hospitalized RSV cases compared to controls. Smaller differences in outcomes were observed when comparing hospitalized RSV cases with hospitalized influenza cases, with varying direction over time. With existing evidence of increased MI and mortality risk after influenza and these findings on MI and mortality risk after RSV, future research should aim to further understand the impact of RSV on cardiovascular outcomes and assess the role of RSV prevention in lowering the risk of MI and mortality.

Challenges in Influenza Control and Surveillance in the Republic of Kazakhstan

The COVID-19 pandemic has significantly disrupted the circulation of influenza viruses in Kazakhstan, highlighting the vulnerabilities in the country’s public health infrastructure. This review critically examines the challenges faced in infiltrating and controlling influenza in Kazakhstan, particularly in light of the shifting epidemiological landscape post-pandemic. Key issues include the decline in influenza cases during the pandemic, which complicates the assessment of influenza epidemiology, vaccine effectiveness, and planning of vaccination campaigns. Although part of the Global Influenza Hospital Surveillance Network (GIHSN), Kazakhstan's surveillance systems face data collection, coordination, and public awareness gaps. The review discusses the prevalence of various influenza strains, the impact of zoonotic infections, and the necessity for improved monitoring frameworks. Additionally, the historical context of infectious disease control in Kazakhstan is explored, emphasising the need for enhanced international collaboration and targeted public health strategies. The findings underscore the importance of vaccination and robust surveillance to mitigate the risks of seasonal and pandemic influenza, advocating for a comprehensive approach to safeguard public health in Kazakhstan.

Systematic Review on Influenza Burden in Emerging Markets in 2018–2023—An Evidence Update to Guide Influenza Vaccination Recommendations

Background: Influenza is a contagious respiratory illness responsible for seasonal epidemics and with potential to cause pandemics. The decline in influenza-related studies published since 2018 resulted in data gaps, particularly in emerging markets. Methods: This systematic review searched for studies in six databases and gray literature sources to define the clinical burden of influenza and influenza-like illness (ILIs) and their associated sequelae among humans across emerging markets. Eligible studies were published in English, Spanish, or Chinese between January 2018 and September 2023 and conducted in Asia, the Middle East, Africa, and Latin America. Results: In total, 256 articles were included, mostly on lab-confirmed influenza infections (n = 218). Incidences of lab-confirmed influenza cases in Asia (range 540–1279 cases/100,000 persons) and Sub-Saharan Africa (range 34,100–47,800 cases/100,000 persons) were higher compared to Latin America (range 0.7–112 cases/100,000 persons) and the Middle East and North Africa (range 0.1–10 cases/100,000 persons). Proportions of lab-confirmed influenza cases and influenza-associated outcomes (i.e., hospitalization, ICU admission and death) varied widely across regions. Temporal variation in influenza trend was observed before and during the COVID-19 pandemic. Conclusions: In conclusion, influenza causes significant disease burden in emerging markets. Robust large real-world studies using a similar methodology are needed to have more accurate estimates and compare studies within age groups and regions. Continuous monitoring of influenza epidemiology is important to inform vaccine programs in emerging markets with heavy influenza disease burden.

Health impact and cost-effectiveness of vaccination using potential next-generation influenza vaccines in Thailand: a modelling study

IntroductionThailand was one of the first low- and middle-income countries to publicly fund seasonal influenza vaccines, but the lack of predictability in the timing of epidemics and difficulty in predicting the dominant influenza subtypes present a challenge for existing vaccines. Next-generation influenza vaccines (NGIVs) are being developed with the dual aims of broadening the strain coverage and conferring longer-lasting immunity. However, there are no economic evaluations of NGIVs in Thailand.MethodsWe estimated the health impact and cost-effectiveness of NGIVs in Thailand between 2005 and 2009 using a combined epidemiological and economic model. We fitted the model to data on laboratory-confirmed influenza cases and then simulated the number of influenza infections, symptomatic cases, hospitalisations and deaths under different vaccination scenarios based on WHO-preferred product characteristics for NGIVs. We used previous estimates of costs and disability adjusted life years (DALYs) for influenza health outcomes to estimate incremental net monetary benefit, vaccine threshold prices and budget impact.ResultsWith the current vaccine programme, there were an estimated 61 million influenza infections. Increasing coverage to 50% using improved vaccines reduced infections to between 23 and 57 million, and with universal vaccines to between 21 and 49 million, depending on the age groups targeted. Depending on the comparator, threshold prices for NGIVs ranged from US$2.80 to US$12.90 per dose for minimally improved vaccines and US$24.60 to US$69.90 for universal vaccines.ConclusionInfluenza immunisation programmes using NGIVs are anticipated to provide considerable health benefits and be cost-effective in Thailand. However, although NGIVs might even be cost-saving in the long run, there could be significant budget implications for the Thai government even if the vaccines can be procured at a substantial discount to the maximum threshold price.

Integrated sentinel surveillance of influenza, SARS-CoV-2, RSV and respiratory viruses in Serbia

Abstract Introduction Integrated sentinel SARI surveillance of influenza, SARS -CoV-2 and RSV has been established in Serbia since 2021-2022 influenza season. Nine sentinel hospitals in 3 cities participated in the SARI surveillance system. The aim of this study is to provide a review of integrated sentinel surveillance of SARI in Serbia in 2023-2024 influenza season, from October 2023 to April 2024. Methods On a weekly basis, both epidemiological and virological data were collected. Surveillance is be conducted year-round. Specimens were tested for influenza, SARS-CoV-2,RSV and other respiratory viruses. Respiratory disease wards, intensive care units (ICUs) and pediatric wards were all represented. Real time polymerase chain reaction (RT-PCR) was used. Results From October 2023 to April 2024, a total of 1571 SARI cases were reported with 100% recorded age. Of these, 35% were 0-4 years old, 16% were 5-14, 6% were 15-29, 14% were 30-64, 18% were 65-79 and 11% were 80+. Among these cases, 1002 (64%) respiratory specimens were collected. The number of positive samples for influenza was 294 (29%). The positivity rate was 10% for SARS-CoV-2 and 19 % for RSV. The highest proportion of laboratory-confirmed influenza cases was 67% in week 04/2023. Then above 50% in week 05/2023 and 06/2023. Type A viruses was predominated, accounting for 97% of all influenza SARI detections. Activity was dominated by A(H3) with 42% positivity rate. Also, collected swabs were tested for rhinoviruses, positivity rate was 26%, for adenoviruses, 12%, for human metapneumovirus, 7% and for parainfluenza 3 viruses, 4%. Conclusions Sustaining and intensified effective integrated surveillance for influenza, SARS-CoV-2,RSV and other respiratory viruses in Serbia is the priority especially in the frame of International Health Regulations. In this way, we improve national capacity for preparedness and emergency response to national and cross-border public health threats. Key messages • Building and maintaining integrated respiratory surveillance that can rapidly integrate the surveillance of a new viruses is crucial. • Establishing well structured surveillance of severe acute respiratory infections, strengthening and expanding respiratory viral surveillance is one the base pillars preparation for future pandemics.

A CDSS based Integrated Pathway for Influenza Vaccination Across Primary and Secondary Care

Abstract Background In Italy, influenza vaccination coverage in people ≥ 65 years is unsatisfactory (56.7%), underlining the need to improve current vaccination strategies. The objectives of this study have been: to define a novel pathway to increase influenza vaccination adherence among ≥ 65 years population in the Lazio region; to provide a predictive estimate of the epidemiological and economic pathway’s potential impact. Methods A multidisciplinary working group (WG) featuring cross-sectoral expertise was created and WG periodic meetings were held to define the patient journey and its flow-chart representation. The pathway’s potential impact was assessed through epidemiological and economic indicators and scenario analyses. Results An integrated pathway across primary and secondary care was defined, based on the active patient in-Hospital recruitment and vaccination and enhanced by a Clinical Decision Support System relying on a digital algorithm to identify eligible patients. Assuming an increase of influenza vaccination coverage from the current rate of 60% (scenario 1) to 65% (scenario 2) in ≥ 65 years population in the Lazio region thanks to the pathway implementation, an increase of 8% in avoided influenza cases, influenza- or pneumonia-related hospitalizations and influenza-related outpatient visits was estimated with a relative increase in savings for hospitalizations and outpatients visits of up 2,367,310 euros. Setting the vaccination coverage at 70% (scenario 3), an increase of 16% in avoided influenza cases, hospitalizations and outpatient visits was estimated with a relative increase in savings for hospitalizations and outpatients’ visits of up to 4,833,259 euros. Conclusions Alongside offering a predictive estimate of the relevant pathway’s potential impact, both epidemiological and economic, this project, with its robust methodology, may serve as a scalable and transferable model for enhancing vaccination coverage at national and international level. Key messages • The proposed pathway, offering the option of receiving flu vaccination within the Hospital, supports the paradigm shift towards primary prevention pathways in secondary care settings. • Another relevant aspect of the integrated pathway is the adoption of an Artificial Intelligence tool to identify suitable patients and improve their recruitment and adherence to vaccination.

A Clinical and Economic Comparison of Cell-Based Versus Recombinant Influenza Vaccines in Adults 18–64 Years in the United States

Background: This analysis compares the cost-effectiveness of a cell-based influenza vaccine to a recombinant influenza vaccine, and each to no vaccination. The analysis is based on United States (US) commercial and societal perspectives. Methods: A Susceptible–Exposed–Infectious–Recovered (SEIR) transmission model of the total US population followed with a cost-effectiveness model for 18–64-year-olds was used to estimate the clinical and economic impact of vaccination over one influenza season (2018–2019). Deterministic and probabilistic sensitivity analyses were conducted. Results: Both enhanced vaccines prevented a substantial number of influenza cases and influenza-related deaths compared to no vaccination. The cell-based vaccine was associated with higher quality-adjusted life years (QALYs) gained compared to the recombinant vaccine or no vaccination. The cell-based vaccine had a 36% lower vaccination cost, amounting to $2.8 billion in cost savings, compared to the recombinant vaccine. The incremental cost-effectiveness ratios (ICERs) for the cell-based vaccine, compared to the recombinant vaccine or no vaccination, were dominant from all payer perspectives, regardless of risk groups. Conclusions: Overall, the cell-based vaccine was cost-saving compared to the recombinant vaccine for subjects aged 18–64 years in the US, achieving comparable health outcomes with a significant reduction in associated costs.

The results of vaccination against novel coronavirus infection in adolescents with allergic diseases

Novel coronavirus infection requires analyzing its course in patients with allergic diseases. Patients with atopic allergic diseases remain insufficiently studied with regard to the peculiarities of the course of both the underlying allergic disease and infectious processes caused by viruses and bacteria. Epithelial cells in bronchial asthma do not respond sufficiently to interferons, suggesting that SARS-CoV-2 infection may suppress spontaneous upregulation of angiotensin-converting enzyme expression, which ultimately reduces disease severity, but at the same time makes patients with allergic atopic diseases susceptible to other viral infections. The results obtained indicate statistically significant differences in the formation of anti-RBD IgG antibodies to SARS-CoV-2 between the group of adolescents with bronchial asthma vaccinated against a new coronavirus infection and those not vaccinated against it. During the follow-up period after 6 months, a statistically significant increase in anti-RBD IgG titer to SARS-CoV-2 due to novel coronavirus infection was observed among the unimmunized children. Clinical parameters indicated a favorable course of atopic process and control of bronchial asthma exacerbations in adolescents who received vaccination against both new coronavirus infection and influenza, while those who did not receive vaccination against these viral infections had bronchial asthma exacerbations due to respiratory infection. Also among patients with bronchial asthma who received influenza vaccination, there were no cases of influenza A and bronchial asthma exacerbations due to respiratory infections. In this regard, influenza vaccination is an important intervention to maintain control of asthma exacerbations. It is noteworthy that no new coronavirus infection was reported among vaccinated adolescents within a year after immunization. At the same time, 6 months after vaccination against a new coronavirus infection, we observed a statistically significant increase in antibody levels in unvaccinated adolescents, indicating the presence of high viral neutralizing activity. Vaccination against novel coronavirus infection in patients with bronchial asthma may be considered a possibility.

Evaluation of the preventive effectiveness of russian influenza vaccines in the epidemic seasons of 2018-2021

Monitoring the effectiveness of influenza vaccines annually enables the development of measures aimed at decreasing influenza incidence, hospitalization, and mortality rates. The epidemiological effectiveness of several Russian domestic influenza vaccines was evaluated in St. Petersburg in the 2018-2021 epidemic seasons. Male and female participants (N = 6912) aged 18-23 were monitored from 2018 to 2021. Sovigripp, Grippol Plus, Ultrix, and Ultrix Quadri inactivated influenza vaccines were used for immunization. In 2018-2019, when the vaccine strains fully matched the circulating influenza viruses, prophylactic vaccination resulted in a 2.7 to 7.1-fold reduction in influenza cases. The protective effectiveness of the vaccines against influenza and acute respiratory infections (ARIs) totalled 52.4%, reaching 73.0% effectiveness against influenza after laboratory confirmation. In the epidemic season 2019-2020, when the circulating viruses and vaccine strains did not fully match, the incidence of influenza and ARIs reduced twice due to vaccination; the total vaccine effectiveness against influenza and ARIs amounted to 50.0%. The Grippol Plus, Ultrix, and Ultrix Quadri vaccines proved to be the most effective, demonstrating a total effectiveness of 70.6%-75.0% and a 65.5%-83.5% effectiveness against influenza A and B. In the 2020-2021 epidemic season, no data on the preventive effectiveness of the influenza vaccines could be obtained due to the outbreak of COVID-19 and the absence of detectable influenza virus shedding in the study participants. The results obtained are consistent with WHO experts’ estimates which indicate that modern influenza vaccines reduce the incidence of influenza in adults by 70-90% if the vaccine strains match the circulating virus strains.

Epidemiology and population-based incidence of influenza in two communities, Bandung district, West Java, Indonesia, 2008–2011

Influenza surveillance is important for monitoring influenza virus circulation and disease burden to inform influenza prevention and control measures. The aim of this study was to describe the epidemiology and to estimate the incidence of influenza in two communities in West Java, Indonesia, before and after the 2009 H1N1 pandemic. A population-based surveillance study in the community health care setting was conducted to estimate the annual incidence of influenza. A real-time reverse transcription polymerase chain reaction (RT-PCR) assay was used for influenza case ascertainment. A population census was implemented to calculate the population at risk and estimate community health care utilization rate. The mean annual incidence of influenza A and B, adjusted for healthcare utilization, was 1.6 (95%CI: 1.3–2.0) and 0.7 (95%CI: 0.5–1.0) per 1000 persons, respectively, with the most affected group being young and school-age children. The annual cumulative incidence of influenza A for children under five in 2009, 2010, and 2011 was 7.0 (95%CI: 4.4–11.2), 10.6 (95%CI: 7.3–15.4), and 6.3 (95%CI: 3.8–10.2). For influenza B was 4.3 (95%CI: 2.4–7.8), 2.0 (95%CI: 0.8–4.7), and 0.4 (95%CI: 0.1–2.8), respectively. This study highlights that the incidence of influenza among young and school-age children is consistently higher compared to adults and the elderly throughout these periods. These populations are potential targets for influenza vaccination in Indonesia.

Birth Outcomes After Pertussis and Influenza Diagnosed in Pregnancy: A Retrospective, Population-Based Study.

Adverse birth outcomes and the maternal severity of influenza in pregnancy are well documented but information on pertussis is limited. Population-based linkage data were collected during 2001-2016. New South Wales, Australia. A total of 1 453 037 singleton births. Cox regression was used to estimate the associations between pertussis or influenza during pregnancy and birth outcomes with adjustment of covariates. Adverse birth outcomes (preterm birth and low birth weight). Among 1 453 037 singleton births over 16 years, we identified pertussis in 925 (49; 5.3% hospitalised) and influenza in 2850 (1092; 38.3% hospitalised) women during pregnancy. Cases of pertussis were similarly distributed by trimester (32% 3rd) whereas 46% of influenza cases were in the 3rd trimester. Younger age, previous birth, and being overseas-born were associated with both pertussis and influenza, whereas identifying as Aboriginal or Torres Strait Islander, hypertension or diabetes before and during pregnancy, and a number of other factors were only associated with influenza. Both pertussis and influenza in pregnancy were associated with increased risk of preterm birth (pertussis: aHR = 1.30, 95% CI 1.01-1.68; influenza: aHR = 1.56, 95% CI 1.36-1.79) and these increased risks were greater when infections in the period within 2 weeks of birth were considered (pertussis: aHR = 2.36, 95% CI 1.26-4.41; influenza: aHR = 2.29, 95% CI 1.78-2.96). Maternal pertussis and influenza infections close to the time of birth were associated with adverse birth outcomes. These findings highlight the benefits of vaccination during pregnancy.

Comparison of Efficacy and Safety of Baloxavir and Oseltamivir in Children With Influenza: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis compared the efficacy and safety of baloxavir marboxil and oseltamivir in treating influenza in children. A comprehensive literature search was conducted across multiple databases, identifying five studies (four observational and one randomized controlled trial) with a pooled sample size of 2,261 patients. The analysis revealed that baloxavir marboxil significantly reduced the duration of fever compared to oseltamivir (mean difference: -13.49 hours, 95% CI: -23.75 to -3.24). However, there was no significant difference in the time to resolution of overall influenza symptoms between the two treatments (mean difference: -4.55 hours, 95% CI: -19.48 to 10.37). Safety analysis, though limited by available data, suggested a lower incidence of nausea and vomiting with baloxavir marboxil compared to oseltamivir. Both drugs demonstrated comparable safety profiles for other adverse events. These findings indicate that while both medications remain viable options for managing pediatric influenza, baloxavir marboxil may offer advantages in terms of rapid fever reduction and potentially fewer gastrointestinal side effects. However, the study highlights the need for more robust, large-scale randomized controlled trials focusing exclusively on pediatric populations to strengthen the evidence base. Clinicians should consider individual patient factors, local resistance patterns, and current guidelines when making treatment decisions. Future research should explore combination therapies and their potential to manage severe influenza cases in children and conduct more comprehensive safety assessments in pediatric populations.

The Recent Increase in Invasive Bacterial Infections: A Report From the National COVID Cohort Collaborative

Background: When coronavirus disease 2019 (COVID-19) mitigation efforts waned, viral respiratory infections (VRIs) surged, potentially increasing the risk of postviral invasive bacterial infections (IBIs). We sought to evaluate the change in epidemiology and relationships between specific VRIs and IBIs [complicated pneumonia, complicated sinusitis and invasive group A streptococcus (iGAS)] over time using the National COVID Cohort Collaborative (N3C) dataset. Methods: We performed a secondary analysis of all prospectively collected pediatric (<19 years old) and adult encounters at 58 N3C institutions, stratified by era: pre-pandemic (January 1, 2018, to February 28, 2020) versus pandemic (March 1, 2020, to June 1, 2023). We compared the characteristics and outcomes of patients with prespecified VRIs and IBIs, including correlation between VRI cases and subsequent IBI cases. Results: We identified 965,777 pediatric and 9,336,737 adult hospitalizations. Compared with pre-pandemic, pandemic-era children demonstrated higher mean monthly cases of adenovirus (121 vs. 79.1), iGAS (5.8 vs. 3.3), complicated pneumonia (282 vs. 178) and complicated sinusitis (29.8 vs. 16.3), P < 0.005 for all. Among pandemic-era children, peak correlation between RSV cases and subsequent complicated sinusitis cases occurred with a 60-day lag (correlation coefficient 0.56, 95% confidence interval: 0.52–0.59, P < 0.001) while peak correlation between influenza and complicated sinusitis occurred with a 33-day lag (0.55, 0.51–0.58, P < 0.001). Correlation among other VRI–IBI pairs was modest during the pandemic and often lower than during the pre-pandemic era. Conclusions: Since COVID-19 emerged, mean monthly cases of iGAS, complicated pneumonia, and complicated sinusitis have been higher. Pandemic-era RSV and influenza cases were correlated with subsequent cases of complicated sinusitis in children. However, many other VRI–IBI correlations decreased during the pandemic.

Temperature variability and influenza incidence in China: Effect modification by ambient fine particulate matter

This study aims to examine the association between temperature variabilit (TV) exposure and influenza incidence in China, and the modification effect of PM2.5 levels. Data on daily influenza cases, weather conditions, and PM2.5 concentrations were collected from 339 cities across mainland China from 2014 to 2019. TV was computed as the standard deviation of daily maximum and minimum temperatures for the current day and the previous several days (i.e., TV0–1 to TV0–7). A space-time-stratified case-crossover design with conditional Poisson regression was employed. Overall, each 1 °C increase in TV0–6 was linked to 3.3 % (95 % CI: 3.1 %, 3.5 %) rise in influenza incidence, potentially attributing 14.73 % (95 % CI: 14.08 %, 15.37 %) of cases to this exposure. PM2.5 concentration showed substantial modification effect on the association, such that the relative risk (RR) of influenza incidence grew from 1.027 (95 % CI: 1.025, 1.029) to 1.040 (95 % CI: 1.038, 1.042) as PM2.5 levels increased from 15 to 75 μg/m³ . Females and individuals over 65 years old were more susceptible to TV exposure and the PM2.5 modification. Stronger effects were observed during cold season and in North region. The findings highlight the integrating considerations of TV and PM2.5 exposures into public health measures for influenza prevention and control.

Evaluation and control strategy analysis of influenza cases in Jiujiang City, Jiangxi Province, China from 2018 to 2022.

According to World Trade Organization (WTO) statistics, the incidence of seasonal influenza in China has been on the rise since 2018. The aim of this study was to identify and investigate the influence of factors related to the incidence of four common types of influenza viruses. Data of patients with common cold and associated virus infections are described, and a logistic regression model based on gender, age and season was established. The relationship between virus type and the above three factors was analyzed in depth and significant (p<0.05) associations noted. We noted a fluctuation trend, with the infection rate of influenza virus showing an upward trend from 2018 to 2019 and from 2021 to 2022 and a downward trend from 2019 to 2021. The total number of cases in adolescents aged 18-30 years was higher than that in the elderly. The impact of different types of influenza virus on the population ranked from large to small, with special roles played by Influenza B/Victoria, H3N2, Influenza A/H1N1 pdm and Influenza B/Yamagata.

The Clinical Effectiveness and Tolerability of Oseltamivir in Unvaccinated Pediatric Influenza Patients during Two Influenza Seasons after the COVID-19 Pandemic: The Impact of Comorbidities on Hospitalization for Influenza in Children

Antiviral therapy such as oseltamivir has been recommended for hospitalized children with suspected and confirmed influenza for almost 20 years. The therapy is officially authorized for newborns two weeks of age or older, however, questions about its safety and effectiveness still surround it. Our goals were to assess the epidemiological features of two consecutive seasonal influenza cases in children following the COVID-19 pandemic; to observe the clinical effectiveness and tolerability of oseltamivir in hospitalized children who were not vaccinated against influenza and had different influenza subtypes, including A(H1N1), A(H3N2), and B; and to identify specific comorbidities associated with influenza in children. We performed an observational study on 1300 children, enrolled between 1 October 2022 and 30 May 2023 and between 1 October 2023 and 4 May 2024, to the IX Pediatric Infectious Diseases Clinical Section of the National Institute of Infectious Diseases “Prof. Dr. Matei Balș”. During the 2022–2023 influenza season, 791 pediatric patients tested positive for influenza and received oseltamivir. Of these, 89% (704/791) had influenza A, with 86.4% having subtype A(H1N1) and 13.6% of cases having A(H3N2), and for influenza B, 11% (87/791) of the pediatric patients. Of the total group, 59% were male, and the median age was 2.4 years (1.02–9.28). For the 2023–2024 influenza season, 509 pediatric patients tested positive for influenza, with 56.9% being of the male gender and who were treated with oseltamivir. Of these patients, 81.6% had influenza A and 18.4% had influenza B. Treatment with neuraminidase inhibitors, specifically oseltamivir, 2 mg/kg/dose administered twice daily for 5 days, was well tolerated by the children, and we recorded no deaths. The duration of hospitalization for patients with a fever after the oseltamivir administration was significantly longer for patients with A(H1N1) infection than A(H3N2), during both seasons. We identified more complications in the 2022–2023 season and a decreasing number of influenza B for the 2023–2024 season. Among children with comorbidities, the most common were asthma, gastrointestinal diseases, and metabolic and endocrine diseases. In terms of effectiveness, oseltamivir significantly reduced the intensity of influenza symptoms, thus reducing the number of days of hospitalization (p = 0.001) as well as post-infection complications (p = 0.005) in both groups. In this study, we evaluated the clinical effectiveness of oseltamivir therapy for all influenza types/subtypes in children, and the length of hospitalization. We identified comorbidities associated with the prolonged duration of hospitalization. Influenza vaccination should be the main tool in the prevention of influenza and its complications in children, especially those with comorbidities.

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.

Out of focus but still relevant? Influenza-related resource utilization and vaccination coverage gaps in adults below 60 years of age with underlying conditions: an analysis of 2016–2024 real-world data in Germany

Background In 2003, the WHO aimed for a 75% or higher influenza vaccination rate among at-risk populations. However, this target was achieved in a few groups during selected seasons in some European countries, and never in Germany. Adults with underlying conditions (UCs) are a critical negleted group for influenza vaccination. This study aimed to identify data gaps in influenza burden and vaccination coverage among adults under 60 with UCs in Germany and bridge these gaps using real-world data. Material and methods We conducted systematic research and analyses using German administrative and claims databases from June 2016 to April 2024. We report on epidemiology, direct care costs, indirect costs from work incapacity, vaccination coverage rates, and describe data gaps. Results Influenza data for high-risk populations are limited. Comprehensive data on influenza epidemiology and vaccination coverage rates (VCR) is available, though with a delay in data availability. Before and after the pandemic, individuals aged 50-59 had the highest rates of influenza-related hospitalization and ICU admission compared to younger age groups. Across all age groups and seasons, individuals with UC experienced higher rates of medically attended influenza cases, hospitalizations, and healthcare costs, with those aged 35–59 being particularly vulnerable. Vaccine coverage was higher in adults aged 35–59 compared to those aged 18–24, and in females compared to males. Limitations Discrepancies of vaccination status, limited data availability, and variations among the extent of UCs. Conclusion In Germany, recent policy measures have mainly targeted those aged 60 and above. While this elderly population experiences the highest disease-related impact, influenza can also lead to substantial healthcare resource utilization (HCRU) and costs in younger populations with chronic UCs; Facilitating vaccination access for this group, such as through pharmacies, is essential. Definition of quantifiable vaccination targets and measures to increase vaccination rates based on these targets are required.

Study of the driving factors of the abnormal influenza A (H3N2) epidemic in 2022 and early predictions in Xiamen, China

BackgroundInfluenza outbreaks have occurred frequently these years, especially in the summer of 2022 when the number of influenza cases in southern provinces of China increased abnormally. However, the exact evidence of the driving factors involved in the prodrome period is unclear, posing great difficulties for early and accurate prediction in practical work.MethodsIn order to avoid the serious interference of strict prevention and control measures on the analysis of influenza influencing factors during the COVID-19 epidemic period, only the impact of meteorological and air quality factors on influenza A (H3N2) in Xiamen during the non coronavirus disease 2019 (COVID-19) period (2013/01/01-202/01/24) was analyzed using the distribution lag non-linear model. Phylogenetic analysis of influenza A (H3N2) during 2013–2022 was also performed. Influenza A (H3N2) was predicted through a random forest and long short-term memory (RF-LSTM) model via actual and forecasted meteorological and influenza A (H3N2) values.ResultsTwenty nine thousand four hundred thirty five influenza cases were reported in 2022, accounting for 58.54% of the total cases during 2013–2022. A (H3N2) dominated the 2022 summer epidemic season, accounting for 95.60%. The influenza cases in the summer of 2022 accounted for 83.72% of the year and 49.02% of all influenza reported from 2013 to 2022. Among them, the A (H3N2) cases in the summer of 2022 accounted for 83.90% of all A (H3N2) reported from 2013 to 2022. Daily precipitation(20–50 mm), relative humidity (70–78%), low (≤ 3 h) and high (≥ 7 h) sunshine duration, air temperature (≤ 21 °C) and O3 concentration (≤ 30 µg/m3, > 85 µg/m3) had significant cumulative effects on influenza A (H3N2) during the non-COVID-19 period. The daily values of PRE, RHU, SSD, and TEM in the prodrome period of the abnormal influenza A (H3N2) epidemic (19–22 weeks) in the summer of 2022 were significantly different from the average values of the same period from 2013 to 2019 (P < 0.05). The minimum RHU value was 70.5%, the lowest TEM value was 16.0 °C, and there was no sunlight exposure for 9 consecutive days. The highest O3 concentration reached 164 µg/m3. The range of these factors were consistent with the risk factor range of A (H3N2). The common influenza A (H3N2) variant genotype in 2022 was 3 C.2a1b.2a.1a. It was more accurate to predict influenza A (H3N2) with meteorological forecast values than with actual values only.ConclusionThe extreme weather conditions of sustained low temperature and wet rain may have been important driving factors for the abnormal influenza A (H3N2) epidemic. A low vaccination rate, new mutated strains, and insufficient immune barriers formed by natural infections may have exacerbated this epidemic. Meteorological forecast values can aid in the early prediction of influenza outbreaks. This study can help relevant departments prepare for influenza outbreaks during extreme weather, provide a scientific basis for prevention strategies and risk warnings, better adapt to climate change, and improve public health.