Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data

Pharmacodynamic Effect of Different Dosage Regimes of Oseltamivir in Severe Influenza Patients Requiring Mechanical Ventilation: A Multicentre Randomised Controlled Trial

BACKGROUND AND OBJECTIVES

This randomised controlled trial evaluated whether higher doses of oseltamivir would improve virological and clinical outcomes in severe influenza patients requiring invasive mechanical ventilation.

METHODS

Forty intubated adult patients with severe influenza A or B from four intensive care units in Hong Kong were enrolled and randomised to receive either a double dose (300 mg/day) or a triple dose (450 mg/day) of oseltamivir for 10 days. Baseline data were collected, and outcomes were assessed daily using SOFA and Murray scores. Viral RNA was quantified from nasopharyngeal and tracheal aspirates. The primary outcome was the viral clearance rate after 5 days of treatment; secondary outcomes included 28-day and hospital mortality rates, changes in viral load, and serial SOFA and Murray scores.

RESULTS

Viral clearance rates after 5 days of treatment were low and similar between the double (3/20, 15%) and triple-dose groups (2/20, 10%). No significant differences were observed in 28-day mortality, hospital mortality, ICU length of stay or duration of mechanical ventilation between the double and triple-dose groups. However, patients receiving triple doses exhibited a faster decline in influenza A viral load but had a longer hospital length of stay.

CONCLUSIONS

Triple doses of oseltamivir did not significantly improve virological or clinical outcomes compared with double doses in severe influenza.

How to manage antivirals in critically ill patients with influenza?

BACKGROUND

Influenza is a significant cause of morbidity and mortality, particularly in critically ill patients. The availability of effective antiviral therapies is pivotal in mitigating the severity and complications associated with influenza.

OBJECTIVES

This review evaluates the antivirals available for the treatment of severe influenza in critically ill patients, focusing on the strength of recommendations and levels of evidence derived from clinical trials, observational studies, and guidelines. The aim is to provide clinicians with evidence-based insights to optimize antiviral strategies in the intensive care unit setting.

SOURCES

A comprehensive literature search was conducted using PubMed, Embase, and Cochrane Library databases for studies published up to January 2025. Keywords included "antiviral therapy," "influenza," "critically ill patients," "oseltamivir," "peramivir," "zanamivir," "lanimavir," "baloxavir," and "favipiravir." Additional references were identified from the bibliographies of relevant articles.

CONTENT

The following topics are covered: antivirals available for treating influenza and evidence supporting their use in critically ill patients, pharmacokinetic issues of enteral oseltamivir administration in critically ill patients, and neuraminidase inhibitors resistance.

IMPLICATIONS

Neuraminidase inhibitors constitute the vast majority of antivirals currently prescribed for influenza. The most commonly prescribed neuraminidase inhibitor to date is oseltamivir. Although its efficacy in nonsevere cases of influenza is well established, the evidence for its efficacy in critically ill patients is based on less robust studies, as no randomized controlled trials have been conducted in this population. Limited data on oseltamivir pharmacokinetics is available in critically ill patients. The selection of A(H1N1)pdm09 resistant variants to oseltamivir is particularly problematic in critically ill patients hospitalized in intensive care units. Data on other antivirals, such as neuraminidase inhibitors (i.e. zanamivir, peramivir and laninamivir) or baloxavir marboxil in critically ill patients are scarce. Further research is needed to develop new drugs and assess their efficacy in critically ill patients and to better assess the effect of oseltamivir in this population.

Cefepime versus carbapenem for treating complicated urinary tract infection caused by cefoxitin-nonsusceptible ESCPM organisms: a multicenter, real-world study

BACKGROUND

This investigation aimed to compare the efficacy of cefepime and carbapenem for complicated urinary tract infection (cUTI) caused by presumptive AmpC β-lactamase-producing Enterobacter spp., Serratia marcescens, Citrobacter freundii, Providencia spp., and Morganella morganii (ESCPM).

METHODS

Data of 458 individuals with cUTI caused by cefoxitin-nonsusceptible [minimum inhibitory concentration (MIC) > 8 µg/mL] and cefepime-susceptible (MIC ≤ 2 µg/mL) ESCPM was acquired from four Chinese hospitals between 2010 and 2022 and were reviewed retrospectively.

RESULTS

125 and 333 patients received cefepime and carbapenems, respectively, as antimicrobial therapy. The 28-day treatment failure rate was 15.7% (72/458). The following factors were identified as independent predictors for 28-day therapy: age, cefepime MIC = 2 µg/mL, immunocompromised status, infection source control, appropriate empirical therapy, and days from illness onset to active therapy. In patients who required cefepime MIC ≤ 1 µg/mL, a multivariate logistic model indicated that cefepime was linked with a similar risk of 28-day treatment failure [odd ratio (OR) 1.791, 95% confidence interval (CI) 0.600-5.350, p = 0.296] compared with carbapenems after controlling these predictors. Compared with individuals with cefoxitin-nonsusceptible ESCPM, those with isolates of cefepime (MIC = 2 µg/mL) had an enhanced risk of 28-day treatment failure (OR = 2.579, 95% CI = 1.012-6.572, p = 0.047). A propensity score for treatment analysis validated this relationship.

CONCLUSIONS

The cefepime and carbapenem had comparable efficacy for treating cUTI caused by cefoxitin-nonsusceptible ESCPM organisms with cefepime MIC ≤ 1 µg/mL, whereas carbapenems are potentially more effective for isolates with cefepime MIC = 2 µg/mL.

Modeling the impact of early vaccination in an influenza pandemic in the United States

We modeled the impact of initiating one-dose influenza vaccination at 3 months vs 6 months after declaration of a pandemic over a 1-year timeframe in the US population. Three vaccine effectiveness (VE) and two pandemic severity levels were considered, using an epidemic curve based on typical seasonal influenza epidemics. Vaccination from 3 months with a high, moderate, or low effectiveness vaccine would prevent ~95%, 84%, or 38% deaths post-vaccination, respectively, compared with 21%, 18%, and 8%, respectively following vaccination at 6 months, irrespective of pandemic severity. While the pandemic curve would not be flattened from vaccination from 6 months, a moderate/high effectiveness vaccine could flatten the curve if administered from 3 months. Overall, speed of initiating a vaccination campaign is more important than VE in reducing the health impacts of an influenza pandemic. Preparedness strategies may be able to minimize future pandemic impacts by prioritizing rapid vaccine roll-out.

Mortality Risk Among Patients With Influenza Illness Admitted to the ICU: A Systematic Review and Meta-Analysis

BACKGROUND

Despite vaccination programs and available treatments, seasonal influenza carries a large mortality burden, especially in intensive care unit (ICU) settings. Understanding the influenza mortality burden in ICU settings can inform treatment planning and resource allocation. Nonetheless, surveillance data on mortality in ICU-admitted patients are scarce and estimates vary greatly. This systematic literature review (SLR) and meta-analysis investigated all-cause mortality risk among ICU-admitted patients with influenza in Europe.

METHODS

We included observational studies conducted in Europe that reported mortality among patients ≥ 6 months of age with influenza admitted to the ICU. Studies published between January-2009 and December-2019 were included. Quality was assessed using a modified Newcastle-Ottawa scale. Pooled all-cause mortality risk was calculated as a proportion using a random-effects model with an inverse variance method. A sensitivity analysis was also conducted, including only studies identified as having low risk of bias.

RESULTS

Thirty-seven studies, reporting on 13,616 patients, were included. All-cause mortality ranged from 0% to 67%. The overall pooled mortality risk estimate was 0.24 (95% CI: 0.20, 0.27). Study heterogeneity was high (Cochran's Q test p < 0.01, I2 = 93%). The sensitivity analysis using only studies identified as having low risk of bias produced a pooled mortality risk of 0.25 (95%CI: 0.21, 0.29).

CONCLUSIONS

These results indicate that approximately a quarter of patients with influenza admitted to the ICU die, reinforcing the need for effective vaccination programs and treatment optimization.

Incidence of severe illness in pediatric influenza outpatients treated with baloxavir or neuraminidase inhibitors

INTRODUCTION

A single oral dose of baloxavir marboxil, a cap-dependent endonuclease inhibitor, is approved for patients with influenza A or B infection; however, real-world evidence is limited. We evaluated the effectiveness of baloxavir vs neuraminidase inhibitors in reducing the incidence of severe illness in influenza outpatients aged 5-11 years.

METHODS

In this retrospective cohort study, we analyzed individual-level data from patients treated with these antivirals, using a large, Japanese health insurance claims database (JMDC). Patients were included at the first date of diagnosis of the influenza virus infection (Day 1) in two influenza seasons. The primary outcome was the incidence of hospitalization from Day 2-14.

RESULTS

Of 196,749 included patients (Season 2018/2019, n = 103,709; Season 2019/2020, n = 93,040), 20.9 % received baloxavir, 38.8 % received oseltamivir, 28.7 % received laninamivir, and 11.6 % received zanamivir. In each treatment group, 61-70 % patients had influenza A. The incidence of hospitalization from Day 2-14 was significantly lower for baloxavir than for oseltamivir, laninamivir, and zanamivir. The adjusted risk ratio (95 % CI) for oseltamivir, laninamivir, and zanamivir were 1.86 (1.30-2.68), 2.11 (1.37-3.25), and 1.90 (1.31-2.77), respectively, compared with baloxavir. Comparative incidence of hospitalizations between agents were unaffected by season or virus type.

CONCLUSION

Using a large, Japanese health insurance claims database, a lower rate of hospitalization was demonstrated in children aged 5-11 years with an influenza virus infection when treated with baloxavir vs neuraminidase inhibitors. Thus, single dose, oral baloxavir may reduce the incidence of severe illness in these patients.

Coronavirus Disease 2019 and Emerging Lung Infections in the Immunocompromised Patient

The immunocompromised are at higher risk of COVID-19 and lung infections, and these are associated with more severe presentations and greater risk of complication, increasing the risks of intensive care unit admission and poor outcomes. However, only limited high-quality data are available about the diagnosis and management of lung infections in this population, with many clinical trials and other large studies excluding the immunocompromised. Well-designed studies are needed to better understand the optimal diagnostic and management options to improve outcomes in the increasingly heterogeneous group of immunocompromised patients.

Timing of Influenza Antiviral Therapy and Risk of Death in Adults Hospitalized With Influenza-Associated Pneumonia, Influenza Hospitalization Surveillance Network (FluSurv-NET), 2012-2019

BACKGROUND

Pneumonia is common in adults hospitalized with laboratory-confirmed influenza, but the association between timeliness of influenza antiviral treatment and severe clinical outcomes in patients with influenza-associated pneumonia is not well characterized.

METHODS

We included adults aged ≥18 years hospitalized with laboratory-confirmed influenza and a discharge diagnosis of pneumonia over 7 influenza seasons (2012-2019) sampled from a multistate population-based surveillance network. We evaluated 3 treatment groups based on timing of influenza antiviral initiation relative to admission date (day 0, day 1, days 2-5). Baseline characteristics and clinical outcomes were compared across groups using unweighted counts and weighted percentages accounting for the complex survey design. Logistic regression models were generated to evaluate the association between delayed treatment and 30-day all-cause mortality.

RESULTS

A total of 26 233 adults were sampled in the analysis. Median age was 71 years and most (92.2%) had ≥1 non-immunocompromising condition. Overall, 60.9% started antiviral treatment on day 0, 29.5% on day 1, and 9.7% on days 2-5 (median, 2 days). Baseline characteristics were similar across groups. Thirty-day mortality occurred in 7.5%, 8.5%, and 10.2% of patients who started treatment on day 0, day 1, and days 2-5, respectively. Compared to those treated on day 0, adjusted odds ratio for death was 1.14 (95% confidence interval [CI], 1.01-1.27) in those starting treatment on day 1 and 1.40 (95% CI, 1.17-1.66) in those starting on days 2-5.

CONCLUSIONS

Delayed initiation of antiviral treatment in patients hospitalized with influenza-associated pneumonia was associated with higher risk of death, highlighting the importance of timely initiation of antiviral treatment at admission.

Efficacy and Safety of Pimodivir Combined With Standard of Care in Hospitalized and Nonhospitalized High-Risk Adolescents and Adults With Influenza A Infection

BACKGROUND

An unmet need exists for effective antivirals to treat patients hospitalized with influenza. The results of 2 phase 3 studies that evaluated the efficacy and safety of pimodivir in combination with investigator-chosen standard of care (SoC) treatment are presented.

METHODS

Hospitalized patients (hospital study; NCT03376321) and high-risk outpatients (outpatient study; NCT03381196) with laboratory-confirmed influenza A infection were randomized 1:1 to 600 mg pimodivir twice daily + SoC or placebo twice daily + SoC for 5 days. For most patients, SoC included oseltamivir. Primary end points were Hospital Recovery Scale (HRS) at day 6 (hospital study) and median time to resolution (TTR) of influenza-related symptoms (outpatient study).

RESULTS

Pimodivir + SoC (oseltamivir) treatment showed no clinical benefit over placebo + SoC on HRS at day 6 (common odds ratio, 0.943; 95% confidence interval [CI], .609-1.462; P = .397; hospital study). A shorter median TTR of 7 symptoms was estimated with pimodivir + SoC versus placebo (92.6 hours; 95% CI, 77.6-104.2 vs 105.1 hours; 95% CI, 92.7-128.6; P = .0216; outpatient study).

CONCLUSIONS

Pimodivir + SoC showed no additional clinical benefit versus SoC treatment alone in hospitalized patients. Pimodivir + SoC demonstrated shorter TTR of influenza symptoms versus placebo + SoC in high-risk outpatients.

CLINICAL TRIAL REGISTRATION

NCT03376321 and NCT03381196.

Oseltamivir Reduces 30-Day Mortality in Older Adults With Influenza: A Pooled Analysis From the 2012-2019 Serious Outcomes Surveillance Network of the Canadian Immunization Research Network

Background

Oseltamivir is recommended for the treatment of adults hospitalized with influenza, but adherence is often suboptimal. This may be due to doubts about the reliability of the evidence supporting its benefits, particularly when initiation is delayed. We aimed to assess the effectiveness of oseltamivir in reducing mortality in older adults hospitalized with influenza, with a focus on the timing of initiation.

Methods

The CIRN-SOS Network gathered data on severe respiratory illnesses across 5 Canadian provinces during the influenza seasons 2012-2019. Individuals aged ≥65 years with confirmed influenza and available antiviral prescription data were included. We compared the 30-day survival rates of hospitalized patients based on oseltamivir prescription status. Kaplan-Meier estimated survival probability and inverse probability of treatment (IPT)-weighted Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. The analyses considered the time to antiviral initiation (>48 vs ≤48 hours).

Results

Among the 8135 influenza patients studied, 2126 did not receive antiviral treatment, whereas 6009 were treated with oseltamivir. A total of 395 patients were hospitalized for >30 days. The overall mortality rate was 8.32 per 1000 person-days, with 53.9% of the deaths occurring within the first week. Oseltamivir recipients had a 18% lower risk of 30-day mortality (IPT-weighted HR, 0.82 [95% CI, .69-.98]). The benefit was significant for influenza A (IPT-weighted HR, 0.74 [95% CI, .61-.91]) but not for influenza B (IPT-weighted HR, 1.12 [95% CI, .81-1.56]). Oseltamivir remained effective even when initiated after 48 hours (IPT-weighted HR, 0.66 [95% CI, .49-.90]). Influenza vaccination did not mediate the effectiveness of oseltamivir in reducing mortality.

Conclusions

Oseltamivir significantly reduces mortality risk in older adults hospitalized with influenza, even when administered after 48 hours, independent of vaccination status. Clinical Trials Registration. NCT01517191.

Influenza and Aging: Clinical Manifestations, Complications, and Treatment Approaches in Older Adults

Influenza, a highly contagious respiratory viral illness, poses significant global health risks, particularly affecting older and those with chronic health conditions. Influenza viruses, primarily types A and B, are responsible for seasonal human infections and exhibit a propensity for antigenic drift and shift, contributing to seasonal epidemics and pandemics. The severity of influenza varies, but severe cases often lead to pneumonia, acute respiratory distress syndrome, and multiorgan failure. Older adults, especially those over 65 years of age, face increased risks of immune senescence, chronic comorbidities, and decreased vaccine efficacy. Globally, influenza affects millions of people annually, with significant morbidity and mortality among older. Epidemiological patterns vary with climate, and risk factors include age, immunocompromised status, and preexisting chronic conditions. In older adults, influenza frequently results in hospitalization and death, which is exacerbated by immunosenescence and biological organ changes associated with aging. Clinical manifestations range from mild symptoms to severe complications such as viral pneumonia and multiorgan failure. Diagnosis often relies on antigen or molecular tests, with radiological examination aiding in severe cases. Treatment primarily involves antiviral agents, such as oseltamivir and peramivir, with the greatest benefit observed when initiated early. Management of severe cases may require hospitalization and supportive care, including addressing complications, such as secondary bacterial infections and cardiovascular events. This article highlights the need for improved vaccination strategies and novel treatments, including monoclonal antibodies and adoptive T cell therapies, to better manage severe influenza infections in vulnerable populations such as older.

Antiviral Use Among Children Hospitalized With Laboratory-Confirmed Influenza Illness: A Prospective, Multicenter Surveillance Study

BACKGROUND

Guidelines state that all hospitalized children with suspected or confirmed influenza receive prompt treatment with influenza-specific antivirals. We sought to determine the frequency of, and factors associated with, antiviral receipt among hospitalized children.

METHODS

We conducted active surveillance of children presenting with fever or respiratory symptoms from 1 December 2016 to 31 March 2020 at 7 pediatric medical centers in the New Vaccine Surveillance Network. The cohort consisted of children hospitalized with influenza A or B confirmed by clinical or research testing. The primary outcome was frequency of antiviral receipt during hospitalization. We used logistic regression to obtain adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for factors associated with antiviral receipt.

RESULTS

A total of 1213 children with laboratory-confirmed influenza were included. Overall, 652 children (53.8%) received an antiviral. Roughly 63.0% of children received clinical influenza testing. Among those with clinical testing, 67.4% received an antiviral. Factors associated with higher odds of antiviral receipt included hematologic (aOR = 1.76; 95% CI = 1.03-3.02) or oncologic/immunocompromising (aOR = 2.41; 95% CI = 1.13-5.11) disorders, prehospitalization antiviral receipt (aOR = 2.34; 95% CI = 1.49-3.67), clinical influenza testing (aOR = 3.07; 95% CI = 2.28-4.14), and intensive care unit admission (aOR = 1.53; 95% CI = 1.02-2.29). Symptom duration >2 days was associated with lower odds of antiviral treatment (aOR = 0.40; 95% CI = .30-.52). Antiviral receipt varied by site with a 5-fold difference across sites.

CONCLUSIONS

Almost half of children hospitalized with influenza did not receive antivirals. Additional efforts to understand barriers to guideline adherence are crucial for optimizing care in children hospitalized with influenza.

Prevalence and Surveillance of Influenza Viruses in Hospitalized Patients with Respiratory Infections in and Around Chennai, Southern Part of India

The COVID-19 pandemic has heightened concerns about increasing cases of human influenza virus, which pose a significant public health threat to the population in and around Chennai. Therefore, this study analyzed the prevalence of influenza viruses, including influenza A (InfA) and its subtypes H1N1 and H3N2, influenza B (InfB), and respiratory syncytial virus (RSV), in the population of Chennai and surrounding areas. The study included 444 nasopharyngeal and oropharyngeal samples collected between September 2022 and March 2023 from hospitalized patients with severe respiratory symptoms. The sample group consisted of 249 men and 195 women between the ages of 1 and 100 years. The collected samples were processed for detection of InfA, H1N1, H3N2, InfB, and RSV according to the guidelines of the Indian Council of Medical Research (ICMR) and the Department of Public Health, Government of Tamil Nadu. InfA and H3N2 were found to be the most prevalent, with prevalence rates of 11.4%, and 5.1%, respectively. They were followed by H1N1 (3.1%), InfB (2.02%), and RSV (0.5%). H3N2 was more frequently observed in adults and elderly aged groups (4.5%). The most common symptoms associated with InfA infection were fever, body aches, cough, and headache. In addition, RSV, H1N1, and H3N2 viral positivity (11.4%, 5.1%, and 0.5%, respectively) were higher in children aged 1-5 years. This study shows that H1N1 and H3N2 viruses were the predominant strains during the study period in Chennai and provides valuable information for public awareness and preventive measures against early influenza virus infections.

Benefit of early oseltamivir therapy for adults hospitalized with influenza A: an observational study

BACKGROUND

clinical guidelines recommend initiation of antiviral therapy as soon as possible for patients hospitalized with confirmed or suspected influenza.

METHODS

A multicenter US observational sentinel surveillance network prospectively enrolled adults (aged ≥18 years) hospitalized with laboratory-confirmed influenza at 24 hospitals during October 1, 2022-July 21, 2023. A multivariable proportional odds model was used to compare peak pulmonary disease severity (no oxygen support, standard supplemental oxygen, high-flow oxygen/non-invasive ventilation, invasive mechanical ventilation, or death) after the day of hospital admission among patients starting oseltamivir treatment on the day of admission (early) versus those who did not (late or not treated), adjusting for baseline (admission day) severity, age, sex, site, and vaccination status. Multivariable logistic regression models were used to evaluate the odds of intensive care unit (ICU) admission, acute kidney replacement therapy or vasopressor use, and in-hospital death.

RESULTS

A total of 840 influenza-positive patients were analyzed, including 415 (49%) who started oseltamivir treatment on the day of admission, and 425 (51%) who did not. Compared with late or not treated patients, those treated early had lower peak pulmonary disease severity (proportional aOR: 0.60, 95% CI: 0.49-0.72), and lower odds of intensive care unit admission (aOR: 0.24, 95% CI: 0.13-0.47), acute kidney replacement therapy or vasopressor use (aOR: 0.40, 95% CI: 0.22-0.67), and in-hospital death (aOR: 0.36, 95% CI: 0.18-0.72).

CONCLUSION

Among adults hospitalized with influenza, treatment with oseltamivir on day of hospital admission was associated reduced risk of disease progression, including pulmonary and extrapulmonary organ failure and death.

Key performance evaluation of commercialized multiplex rRT-PCR kits for respiratory viruses: implications for application and optimization

Respiratory tract infections (RTIs) caused by viruses are prevalent and significant conditions in clinical settings. Accurate and effective detection is of paramount importance in the diagnosis, treatment, and prevention of viral RTIs. With technological advancements, multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been developed and extensively adopted for the diagnosis of viral RTIs. Given the potential challenges in the detection performance of multiplex assays, this study evaluated the analytical sensitivity and competitive interference of the six most commonly used multiplex rRT-PCR kits for detection of respiratory viruses in China. The results revealed that the limits of detection were variable across the viruses and kits. Most of the evaluated multiplex kits demonstrated comparable or enhanced analytical sensitivity compared with singleplex kits for clinically significant viruses, including human adenovirus (HAdV)-3, HAdV-7, Omicron BA.5, H1N1pdm09, H3N2, B/Victoria, respiratory syncytial virus subtype A, and respiratory syncytial virus subtype B, whereas multiplex kits showed relatively less analytical sensitivity for human rhinovirus-B72, human metapneumovirus-A2, parainfluenza virus (PIV)-1, and PIV-3. In addition, most multiplex kits successfully identified co-infections when one analyte was present at a low concentration and another analyte was present at a high concentration.

IMPORTANCE

The complexity and severity of viral respiratory tract infections (RTIs) emphasize the pivotal role of precise diagnosis for viral RTIs in guiding effective public health responses and ensuring appropriate medical interventions, given the substantial population at risk. This study highlights the necessity and importance of evaluating the analytical validity of multiplex real-time reverse transcription polymerase chain reaction assays, offering valuable insights into their optimization and application.

Targeted recruitment of immune effector cells for rapid eradication of influenza virus infections

Despite much research, considerable data suggest that influenza virus remains a serious health problem because i) the effectiveness of current vaccines ranges only from 19% to 60%, ii) available therapies remain ineffective in advanced stages of disease, iii) death rates vary between 25,000 and 72,000/year in the United States, and iv) avian influenza strains are now being transmitted to dairy cattle that in turn are infecting humans. To address these concerns, we have developed zanDR, a bispecific small molecule that binds and inhibits viral neuraminidase expressed on both free virus and virus-infected cells and recruits naturally occurring anti-rhamnose and anti-dinitrophenyl (DNP) antibodies with rhamnose and DNP haptens. Because the neuraminidase inhibition replicates the chemotherapeutic mechanism of zanamivir and oseltamivir, while rhamnose and DNP recruit endogenous antibodies much like an anti-influenza vaccine, zanDR reproduces most of the functions of current methods of protection against influenza virus infections. Importantly, studies on cells in culture demonstrate that both of the above protective mechanisms remain highly functional in the zanDR conjugate, while studies in lethally infected mice with advanced-stage disease establish that a single intranasal dose of zanDR not only yields 100% protection but also reduces lung viral loads faster and ~1,000× more thoroughly than current antiviral therapies. Since zanDR also lowers secretion of proinflammatory cytokines and protects against virus-induced damage to the lungs better than current therapies, we suggest that combining an immunotherapy with a chemotherapy in single pharmacological agent constitutes a promising approach for treating the more challenging forms of influenza.

Committee on Infectious Diseases, O’Leary ST, Campbell JD, Ardura MI, Bryant KA, Caserta MT, Espinosa C, Frenck RW, Healy CM, John CC, Kourtis AP, Milstone A, Myers A, Pannaraj P, Ratner AJ, Bryant KA, Hofstetter AM, Chaparro JD, Michel JJ, Kimberlin DW, Banerjee R, Barnett ED, Lynfield R, Sawyer MH, Barton-Forbes M, Cardemil CV, Farizo KM, Kafer LM, Moore D, Okeke C, Prestel C, Patel M, Starke JR, Thompson J, Torres JP, Wharton M, Woods CR, Gibbs G. Recommendations for Prevention and Control of Influenza in Children, 2024-2025: Technical Report

This technical report accompanies the recommendations of the American Academy of Pediatrics for the routine use of influenza vaccine and antiviral medications in the prevention and treatment of influenza in children during the 2024 to 2025 season. The rationale for the American Academy of Pediatrics recommendation for annual influenza vaccination of all children without medical contraindications starting at 6 months of age is provided. Influenza vaccination is an important strategy for protecting children and the broader community against influenza. This technical report summarizes recent influenza seasons, morbidity and mortality in children, vaccine effectiveness, and vaccination coverage and provides detailed guidance on vaccine storage, administration, and implementation. The report also provides a brief background on inactivated (nonlive) and live attenuated influenza vaccines, available vaccines for the 2024-2025 influenza season, vaccination during pregnancy and breastfeeding, diagnostic testing for influenza, and antiviral medications for treatment and chemoprophylaxis. Strategies to promote vaccine uptake are emphasized.

Influenza in Pregnancy: Maternal, Obstetric, and Fetal Implications, Diagnosis, and Management

Influenza(flu) in pregnancy is associated with higher rates of hospitalization, ICU admission, and death and with increased odds of congenital anomalies and stillbirth, but not preterm birth. Clinical manifestations of flu in pregnancy are the same as nonpregnant patients. Pregnant individuals with flu-like symptoms or flu exposure should be treated with antivirals. Diagnostic testing is not needed. Oseltamivir is the mainstay of treatment(and prophylaxis), and when given within 48 hours of symptom onset, it decreases morbidity and mortality. Influenza is associated with worse maternal, obstetric, and neonatal outcomes. These risks are mitigated by early oseltamivir treatment and maternal vaccination; hence the recommendation for universal vaccination in pregnancy.

Antivirals for treatment of severe influenza: a systematic review and network meta-analysis of randomised controlled trials

BACKGROUND

The optimal antiviral drug for treatment of severe influenza remains unclear. To support updated WHO influenza clinical guidelines, this systematic review and network meta-analysis evaluated antivirals for treatment of patients with severe influenza.

METHODS

We systematically searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Global Health, Epistemonikos, and ClinicalTrials.gov for randomised controlled trials published up to Sept 20, 2023, that enrolled hospitalised patients with suspected or laboratory-confirmed influenza and compared direct-acting influenza antivirals against placebo, standard care, or another antiviral. Pairs of coauthors independently extracted data on study characteristics, patient characteristics, antiviral characteristics, and outcomes, with discrepancies resolved by discussion or by a third coauthor. Key outcomes of interest were time to alleviation of symptoms, duration of hospitalisation, admission to intensive care unit, progression to invasive mechanical ventilation, duration of mechanical ventilation, mortality, hospital discharge destination, emergence of antiviral resistance, adverse events, adverse events related to treatments, and serious adverse events. We conducted frequentist network meta-analyses to summarise the evidence and evaluated the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. This study is registered with PROSPERO, CRD42023456650.

FINDINGS

Of 11 878 records identified by our search, eight trials with 1424 participants (mean age 36-60 years for trials that reported mean or median age; 43-78% male patients) were included in this systematic review, of which six were included in the network meta-analysis. The effects of oseltamivir, peramivir, or zanamivir on mortality compared with placebo or standard care without placebo for seasonal and zoonotic influenza were of very low certainty. Compared with placebo or standard care, we found low certainty evidence that duration of hospitalisation for seasonal influenza was reduced with oseltamivir (mean difference -1·63 days, 95% CI -2·81 to -0·45) and peramivir (-1·73 days, -3·33 to -0·13). Compared with standard care, there was little or no difference in time to alleviation of symptoms with oseltamivir (0·34 days, -0·86 to 1·54; low certainty evidence) or peramivir (-0·05 days, -0·69 to 0·59; low certainty evidence). There were no differences in adverse events or serious adverse events with oseltamivir, peramivir, and zanamivir (very low certainty evidence). Uncertainty remains about the effects of antivirals on other outcomes for patients with severe influenza. Due to the small number of eligible trials, we could not test for publication bias.

INTERPRETATION

In hospitalised patients with severe influenza, oseltamivir and peramivir might reduce duration of hospitalisation compared with standard care or placebo, although the certainty of evidence is low. The effects of all antivirals on mortality and other important patient outcomes are very uncertain due to scarce data from randomised controlled trials.

FUNDING

World Health Organization.

The recommendations and the way forward to fight human infections caused by influenza A (H1N1) in Brazil

Many recent outbreaks of influenza A (H1N1) in the world, especially in Brazil, it has become clear that the severity of the disease is not known in the same form. On Wednesday, June 7, 2023, Brazil notified the WHO of a fatal case of human infection with a variant of the influenza A(H1N1) virus of swine origin, this case was confirmed in a laboratory in the region of the interior state of Paraná. This is the first human infection caused by an influenza A (H1N1) virus reported in 2023 nationwide in Brazil. To mitigate H1N1 flu in Brazil, we urge the Brazillian government through its Ministry of Health to improve on mass awareness about the signs and symptoms of H1N1 flu among the Brazillians. The Brazillian government should also implement the One Health approach towards the control of H1N1 flu in Brazil, as we believe that these recommendations would go a long way in preventing future cases and the spread of H1N1 flu in Brazil. This article aims to present the clinical presentations of the H1N1 flu and the implications, recommendations and the way forward to protect the Brazilian population against the H1N1 flu.

Safety and effectiveness of baloxavir marboxil and oseltamivir for influenza in children: a real-world retrospective study in China

Objectives

To evaluate the safety and effectiveness of baloxavir marboxil (baloxavir) and oseltamivir in pediatric influenza patients in China.

Methods

Patients filling a prescription for baloxavir or oseltamivir within 48 h following an influenza-related outpatient visit were identified in Children's Hospital of Fudan University in China between March 2023 and December 2023. Outcomes were assessed after antiviral treatment and included the incidence of adverse reactions and the duration of fever and other flu symptoms.

Results

A total of 1430 patients infected with influenza A were collected and 865 patients (baloxavir: n = 420; oseltamivir: n = 445) finally included. The incidence of adverse reactions of nausea and vomiting was significantly different between the baloxavir group (2.38%) and the oseltamivir group (12.13%) [P < 0.001, OR = 4.2526, 95%CI (2.0549, 9.6080)]. No differences in other adverse reactions were observed between the two groups. The mean duration of fever in baloxavir group (1.43d) was significantly shorter than that in oseltamivir group (2.31d) [P < 0.001, 95%CI (0.7815, 0.9917)]. There were no differences in the mean duration of nasal congestion and runny nose, sore throat, cough, and muscle soreness between two groups.

Conclusions

The incidence of nausea and vomiting is lower with baloxavir compared to oseltamivir, and the duration for complete fever reduction is shorter with baloxavir than with oseltamivir. The results indicate that baloxavir is well tolerated and effective in Chinese children.

The effect of early versus late remdesivir treatment in hospitalized mild to moderate COVID-19 patients in the Omicron era: A retrospective study

Although real-world studies have found that remdesivir is effective in preventing poor prognosis, more information is needed on the optimal timing of remdesivir administration in high-risk coronavirus disease 2019 (COVID-19) patients in the Omicron era. From February 2022 to January 2023, a single-center retrospective study was performed in Korea. We compared the clinical characteristics and treatment outcomes between early (remdesivir treatment within 0-3 days from symptom onset) and late (≥ 4 days from symptom onset) treatment groups of patients who received remdesivir monotherapy. Of 284 patients, 225 were classified into the early treatment group and 59 were classified into the late treatment group. The early treatment group had a lower rate of 28-day progression to severe disease than the late treatment group (1.4% vs 7.4%, P = .03). Delaying remdesivir treatment ≥ 4 days from symptom onset (adjusted odds ratio [aOR], 6.17; 95% CI, 1.18-32.44; P = .03) and Charlson comorbidity index ≥ 3 (aOR, 9.62; 95% CI, 1.65-56.10; P = .01) were independent risk factors for 28-day progression to severe disease. Our results suggest that early administration of remdesivir could be associated with better prognosis in COVID-19 patients with the Omicron variant, and within 3 days from symptom onset seems to be the appropriate timing.

Considerations when treating influenza infections with oseltamivir

INTRODUCTION

Since the coronavirus disease 2019-mandated social distancing policy has been lifted worldwide, the circulation of influenza is expected to resume. Currently, oseltamivir is approved as the first-line agent for influenza prevention and treatment.

AREAS COVERED

This paper reviews the updated evidence in the pharmacology, resistance mechanisms, clinical pharmacy management, and real-world data on oseltamivir for influenza.

EXPERT OPINION

Oseltamivir is an oral prodrug of oseltamivir carboxylate, an influenza A and B neuraminidase inhibitor. Recently, the therapeutic efficacy of oseltamivir has been demonstrated in several trials. Oseltamivir is generally well-tolerated but may lead to neuropsychiatric events and bleeding. Oseltamivir-resistant influenza virus has been associated with the H275Y mutation in the influenza A(H1N1)pdm09 virus, while most strains are still sensitive to oseltamivir. Dose adjustment for oseltamivir should be based on creatinine clearance and body weight in pediatric patients with renal failure. According to real-world data from Nanfang Hospital, the annual number of patients prescribed oseltamivir declined from 35,711 in 2019 to 8,971 in 2020, with marked increases in 2022 (20,213) and 2023 (18,071). Among the 206 inpatients, children aged < 6 years who were treated with oseltamivir had the shortest duration to defervescence.

Cost-consequence analysis of a combined COVID-19/influenza rapid diagnostic test in the Brazilian private healthcare setting

Combination COVID-19/influenza rapid tests provide a way to quickly and accurately differentiate between the two infections. The goal of this economic evaluation was to assess the cost and health benefits of a combination COVID-19/influenza Rapid Diagnostic Test (RDT) vs. current standard-of-care in the Brazilian private healthcare setting. A dual decision tree model was developed to estimate the impact of rapid differentiation of COVID-19 and influenza in a hypothetical cohort of 1,000 adults with influenza-like illness in an ambulatory healthcare setting. The model compared the use of a combination COVID-19/influenza RDT to Brazil standard diagnostic practice of a COVID-19 RDT and presumptive influenza diagnosis. Different levels of influenza prevalence were modeled with co-infection estimated as a function of the COVID-19 prevalence. Outcomes included accuracy of diagnosis, antiviral prescriptions and healthcare resource use (hospital bed days and ICU occupancy). Depending on influenza prevalence, considering 1,000 patients with influenza-like illness, a combination RDT compared to standard practice was estimated to result in between 88 and 149 fewer missed diagnoses of influenza (including co-infection), 161 to 185 fewer cases of over-diagnosis of influenza; a 24 to 34% reduction in hospital bed days and a 16 to 26% reduction in ICU days. In the base case scenario (20% influenza, 5% COVID-19), the combination RDT was estimated to result in cohort cost savings of $99. Based upon a de novo economic model, this analysis indicates that use of a combination RDT could positively impact influenza antiviral prescriptions and lower healthcare resource use.

Treating influenza with neuraminidase inhibitors: an update of the literature

INTRODUCTION

Influenza affects individuals of all ages and poses a significant threat during pandemics, epidemics, and sporadic outbreaks. Neuraminidase inhibitors (NAIs) are currently the first choice in the treatment and prevention of influenza, but their use can be hindered by viral resistance.

AREAS COVERED

This review summarizes current NAIs pharmacological profiles, their current place in therapy, and the mechanisms of viral resistance and outlines possible new indications, ways of administration, and novel candidate NAIs compounds.

EXPERT OPINION

NAIs represent a versatile group of compounds with diverse administration methods and pharmacokinetics. While the prevalence of influenza virus resistance to NAIs remains low, there is heightened vigilance due to the pandemic potential of influenza. Several novel NAIs and derivatives are currently under assessment at various stages of development for the treatment and prevention of influenza.

Further preclinical characterization of molnupiravir against SARS-CoV-2: Antiviral activity determinants and viral genome alteration patterns

The SARS-CoV-2 pandemic has highlighted the need for broad-spectrum antiviral drugs to respond promptly to viral emergence. We conducted a preclinical study of molnupiravir (MOV) against SARS-CoV-2 to fully characterise its antiviral properties and mode of action. The antiviral activity of different concentrations of MOV was evaluated ex vivo on human airway epithelium (HAE) and in vivo in a hamster model at three escalating doses (150, 300 and 400 mg/kg/day) according to three different regimens (preventive, pre-emptive and curative). We assessed viral loads and infectious titres at the apical pole of HAE and in hamster lungs, and MOV trough concentration in plasma and lungs. To explore the mode of action of the MOV, the entire genomes of the collected viruses were deep-sequenced. MOV effectively reduced viral titres in HAE and in the lungs of treated animals. Early treatment after infection was a key factor in efficacy, probably associated with high lung concentrations of MOV, suggesting good accumulation in the lung. MOV induced genomic alteration in viral genomes with an increase in the number of minority variants, and predominant G to A transitions. The observed reduction in viral replication and its mechanism of action leading to lethal mutagenesis, supported by clinical trials showing antiviral action in humans, provide a convincing basis for further research as an additional means in the fight against COVID-19 and other RNA viruses.

Clinical Diagnosis Is Highly Predictive of Laboratory-Confirmed Mpox in a Sexual Health Clinic

BACKGROUND

Promptly recognizing mpox can facilitate earlier diagnosis and appropriate treatment. How accurately clinicians can diagnose mpox based on clinical data and before receiving molecular test results is not known.

METHODS

Leveraging public health and clinical data collected in Seattle-King County's Sexual Health Clinic (SHC) from July 29, 2022, to September 30, 2022, we analyzed the proportion of patients who received presumptive versus results-based tecovirimat when clinicians had a high, intermediate, or low suspicion for mpox after clinical evaluation. We calculated the sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) of this approach against criterion standard mpox polymerase chain reaction (PCR) results.

RESULTS

Of 321 patients evaluated for mpox in the SHC, median age was 34.5 years and 88% were cisgender men. Overall, 121 of 319 (38%) tested positive by mpox PCR. Clinicians had high suspicion for mpox in 122 patients and offered empiric tecovirimat to 92 (88%), of whom 85 (92%) tested PCR positive. Of 13 intermediate suspicion patients offered presumptive therapy, all accepted but none tested positive by PCR. The sensitivity, specificity, PPV, and NPV of high/intermediate clinical suspicion for mpox were 99%, 90%, 86%, and 99%, respectively. A higher proportion of people with HIV were diagnosed with mpox (57% vs. 36%, P = 0.01, χ2 test), and sensitivity and PPV of high/intermediate clinical suspicion in this subgroup were 100% and 86%, respectively.

CONCLUSIONS

Clinical providers working in a high-volume, public SHC were able to both accurately identify and rule out mpox based on clinical examination before receiving PCR test results.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Latest developments in early diagnosis and specific treatment of severe influenza infection

Influenza pandemics are unpredictable recurrent events with global health, economic, and social consequences. The objective of this review is to provide an update on the latest developments in early diagnosis and specific treatment of the disease and its complications, particularly with regard to respiratory organ failure. Despite advances in treatment, the rate of mortality in the intensive care unit remains approximately 30%. Therefore, early identification of potentially severe viral pneumonia is extremely important to optimize treatment in these patients. The pathogenesis of influenza virus infection depends on viral virulence and host response. Thus, in some patients, it is associated with an excessive systemic response mediated by an authentic cytokine storm. This process leads to severe primary pneumonia and acute respiratory distress syndrome. Initial prognostication in the emergency department based on comorbidities, vital signs, and biomarkers (e.g., procalcitonin, ferritin, human leukocyte antigen-DR, mid-regional proadrenomedullin, and lactate) is important. Identification of these biomarkers on admission may facilitate clinical decision-making to determine early admission to the hospital or the intensive care unit. These decisions are reached considering pathophysiological circumstances that are associated with a poor prognosis (e.g., bacterial co-infection, hyperinflammation, immune paralysis, severe endothelial damage, organ dysfunction, and septic shock). Moreover, early implementation is important to increase treatment efficacy. Based on a limited level of evidence, all current guidelines recommend using oseltamivir in this setting. The possibility of drug resistance should also be considered. Alternative options include other antiviral drugs and combination therapies with monoclonal antibodies. Importantly, it is not recommended to use corticosteroids in the initial treatment of these patients. Furthermore, the implementation of supportive measures for respiratory failure is essential. Current recommendations are limited, heterogeneous, and not regularly updated. Early intubation and mechanical ventilation is the basic treatment for patients with severe respiratory failure. Prone ventilation should be promptly performed in patients with acute respiratory distress syndrome, while early tracheostomy should be considered in case of planned prolonged mechanical ventilation. Clinical trials on antiviral treatment and respiratory support measures specifically for these patients, as well as specific recommendations for different at-risk populations, are necessary to improve outcomes.

Comparison of influenza- and COVID-19-associated pulmonary aspergillosis in China

PURPOSE

We conducted a monocentric retrospective study using the latest definitions to compare the demographic, clinical, and biological characteristics of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA).

METHODS

The study retrospectively enrolled 180 patients, including 70 influenza/IPA patients (with positive influenza A/B and Aspergillus) and 110 COVID-19/IPA patients (with positive SARS-CoV-2 and Aspergillus). Among them, 42 (60%) and 30 (27.3%) patients fulfilled the definitions of IAPA and CAPA, respectively.

RESULTS

The CAPA patients had significantly higher in-hospital mortality (13/31, 41.9%) than IAPA patients (8/42, 19%) with a P-value of 0.033. Kaplan-Meier survival curve also showed significantly higher 30-day mortality for CAPA patients (P = 0.025). Additionally, the CAPA patients were older, though insignificantly, than IAPA patients (70 (60-80) vs. 62 (52-72), P = 0.075). A lower percentage of chronic pulmonary disease (12.9 vs. 40.5%, P = 0.01) but higher corticosteroids use 7 days before and after ICU admission (22.6% vs. 0%, P = 0.002) were found in CAPA patients. Notably, there were no significant differences in the percentage of ICU admission or ICU mortality between the two groups. In addition, the time from observation to Aspergillus diagnosis was significantly longer in CAPA patients than in IAPA patients (7 (2-13) vs. 0 (0-4.5), P = 0.048).

CONCLUSION

Patients infected with SARS-CoV-2 and Aspergillus during the concentrated outbreak of COVID-19 in China had generally higher in-hospital mortality but a lower percentage of chronic pulmonary disease than those infected with influenza and Aspergillus. For influenza-infected patients who require hospitalization, close attention should be paid to the risk of invasive aspergillosis upfront.

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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Adherence to seasonal influenza vaccination and starting antiviral treatment within 48 h of symptom onset can reduce pneumonia risk in severe influenza cases.

Can Haematological Parameters Discriminate COVID-19 from Influenza?

Symptoms of COVID-19 are similar to the influenza virus, but because treatments and prognoses are different, it is important to accurately and rapidly differentiate these diseases. The aim of this study was to evaluate whether the analysis of complete blood count (CBC), including cellular population (CPD) data of leukocytes and automated flow cytometry analysis, could discriminate these pathologies. In total, 350 patients with COVID-19 and 102 patients with influenza were included between September 2021 and April 2022 in the tertiary hospital of Suresnes (France). Platelets were lower in patients with influenza than in patients with COVID-19, whereas the CD16pos monocyte count and the ratio of the CD16pos monocytes/total monocyte count were higher. Significant differences were observed for 9/56 CPD of COVID-19 and flu patients. A logistic regression model with 17 parameters, including among them 11 CPD, the haemoglobin level, the haematocrit, the red cell distribution width, and B-lymphocyte and CD16pos monocyte levels, discriminates COVID-19 patients from flu patients. The sensitivity and efficiency of the model were 96.2 and 86.6%, respectively, with an area under the curve of 0.862. Classical parameters of CBC are very similar among the three infections, but CPD, CD16pos monocytes, and B-lymphocyte levels can discriminate patients with COVID-19.

A Pan-Respiratory Antiviral Chemotype Targeting a Host Multi-Protein Complex

We present a novel small molecule antiviral chemotype that was identified by an unconventional cell-free protein synthesis and assembly-based phenotypic screen for modulation of viral capsid assembly. Activity of PAV-431, a representative compound from the series, has been validated against infectious virus in multiple cell culture models for all six families of viruses causing most respiratory disease in humans. In animals this chemotype has been demonstrated efficacious for Porcine Epidemic Diarrhea Virus (a coronavirus) and Respiratory Syncytial Virus (a paramyxovirus). PAV-431 is shown to bind to the protein 14-3-3, a known allosteric modulator. However, it only appears to target the small subset of 14-3-3 which is present in a dynamic multi-protein complex whose components include proteins implicated in viral lifecycles and in innate immunity. The composition of this target multi-protein complex appears to be modified upon viral infection and largely restored by PAV-431 treatment. Our findings suggest a new paradigm for understanding, and drugging, the host-virus interface, which leads to a new clinical therapeutic strategy for treatment of respiratory viral disease.

Impact of antiviral therapy on short- and long-term outcomes of patients with chronic obstructive pulmonary disease after influenza infection

Background

Respiratory complications often accompany influenza in patients with chronic obstructive pulmonary disease (COPD). In this retrospective study, we quantified the impact of antiviral therapy on exacerbations, healthcare resource utilization (HRU), and costs in patients with COPD across 5 influenza seasons.

Methods

Using claims data from US MarketScan® databases, we identified patients with COPD who had an influenza diagnosis during the 2012-2016 influenza seasons. Patients who received a neuraminidase inhibitor within 48 h of diagnosis (N = 4134) were identified and propensity score-matched 1:1 to a comparator cohort of untreated patients. We determined COPD- and pneumonia-related HRU and costs during month 1, each subsequent quarter, and months 2-13.

Results

Antiviral-treated patients had a significantly lower frequency of COPD-related outcomes than untreated patients during all periods (exacerbations: 10.4% vs 18.2% [month 1] and 17.7% vs 24.2% [months 2-13]; inpatient visit: 2.5% vs 7.9% [month 1] and 3.8% vs 6.7% [months 2-13]; P < 0.0001, all comparisons). Treated patients also had significantly lower outpatient and emergency department (ED) visits beyond month 1. Pneumonia-related inpatient, ED, and outpatient visits were significantly lower in antiviral-treated patients than in untreated patients over all periods (P < 0.0001, all comparisons). In all HRU categories, COPD- and pneumonia-related costs were significantly lower in treated patients over all periods (month-1 ED visit costs were higher).

Conclusions

Antiviral treatment in patients with COPD and influenza is associated with significantly lower HRU and costs in the postinfection month and for an entire year following infection compared with untreated patients.

Distinguishing Swine Flu (H1N1) from COVID-19: Clinical, Virological, and Immunological Perspectives

This article provides an in-depth examination on the differences between the influenza A strain, H1N1 (also called Swine Flu) and Covid-19 focusing on the immune response and clinical symptoms. Flu symptoms due to influenza A strain, H1N1, were initially discovered in 2009. This variant of influenza A is believed to have emerged through reassortment, a process where the resulting virus inherits gene segments from each of its parental viruses. This reassortment event has resulted in a variant with altered characteristics, potentially affecting the level of immunity in humans. The symptoms of this strain typically manifest 1-4 days after exposure and include fever, cough, sore throat, runny/stuffy nose, body aches, fatigue, and gastrointestinal symptoms such as diarrhea. The transmission dynamics of this new variant, including human-to-human transmission, are still under investigation by health authorities. Individuals with weakened immune systems are generally more susceptible to severe illness. Risk factors associated with swine flu can include older adults, young children, pregnant women, and individuals with obesity. Historical variants of swine flu, such as the 2015 variant in India, have been associated with significant case numbers and deaths, often due to respiratory failure. Since the epidemic of Covid-19 due to SARS-CoV2 in early 2020, several symptoms of COVID-19 and swine flu overlap. In this article, we critically reviewed the differences and similarities in the immune response and clinical symptoms due to H1N1 virus and SARS-CoV2 in human.

Application of Nanopore Sequencing in the Diagnosis and Treatment of Pulmonary Infections

This review provides an in-depth discussion of the development, principles and utility of nanopore sequencing technology and its diverse applications in the identification of various pulmonary pathogens. We examined the emergence and advancements of nanopore sequencing as a significant player in this field. We illustrate the challenges faced in diagnosing mixed infections and further scrutinize the use of nanopore sequencing in the identification of single pathogens, including viruses (with a focus on its use in epidemiology, outbreak investigation, and viral resistance), bacteria (emphasizing 16S targeted sequencing, rare bacterial lung infections, and antimicrobial resistance studies), fungi (employing internal transcribed spacer sequencing), tuberculosis, and atypical pathogens. Furthermore, we discuss the role of nanopore sequencing in metagenomics and its potential for unbiased detection of all pathogens in a clinical setting, emphasizing its advantages in sequencing genome repeat areas and structural variant regions. We discuss the limitations in dealing with host DNA removal, the inherent high error rate of nanopore sequencing technology, along with the complexity of operation and processing, while acknowledging the possibilities provided by recent technological improvements. We compared nanopore sequencing with the BioFire system, a rapid molecular diagnostic system based on polymerase chain reaction. Although the BioFire system serves well for the rapid screening of known and common pathogens, it falls short in the identification of unknown or rare pathogens and in providing comprehensive genome analysis. As technological advancements continue, it is anticipated that the role of nanopore sequencing technology in diagnosing and treating lung infections will become increasingly significant.

Structural Investigations of Interactions between the Influenza a Virus NS1 and Host Cellular Proteins

The Influenza A virus is a continuous threat to public health that causes yearly epidemics with the ever-present threat of the virus becoming the next pandemic. Due to increasing levels of resistance, several of our previously used antivirals have been rendered useless. There is a strong need for new antivirals that are less likely to be susceptible to mutations. One strategy to achieve this goal is structure-based drug development. By understanding the minute details of protein structure, we can develop antivirals that target the most conserved, crucial regions to yield the highest chances of long-lasting success. One promising IAV target is the virulence protein non-structural protein 1 (NS1). NS1 contributes to pathogenicity through interactions with numerous host proteins, and many of the resulting complexes have been shown to be crucial for virulence. In this review, we cover the NS1-host protein complexes that have been structurally characterized to date. By bringing these structures together in one place, we aim to highlight the strength of this field for drug discovery along with the gaps that remain to be filled.

Developing and validating clinical features-based machine learning algorithms to predict influenza infection in influenza-like illness patients

BACKGROUND

Seasonal influenza poses a significant risk, and patients can benefit from early diagnosis and treatment. However, underdiagnosis and undertreatment remain widespread. We developed and compared clinical feature-based machine learning (ML) algorithms that can accurately predict influenza infection in emergency departments (EDs) among patients with influenza-like illness (ILI).

MATERIAL AND METHODS

We conducted a prospective cohort study in five EDs in the US and Taiwan from 2015 to 2020. Adult patients visiting the EDs with symptoms of ILI were recruited and tested by real-time RT-PCR for influenza. We evaluated seven ML algorithms and compared their results with previously developed clinical prediction models.

RESULTS

Out of the 2189 enrolled patients, 1104 tested positive for influenza. The eXtreme Gradient Boosting achieved superior performance with an area under the receiver operating characteristic curve of 0.82 (95% confidence interval [CI] = 0.79-0.85), with a sensitivity of 0.92 (95% CI = 0.88-0.95), specificity of 0.89 (95% CI = 0.86-0.92), and accuracy of 0.72 (95% CI = 0.69-0.76) in the testing set over cut-offs of 0.4, 0.6 and 0.5, respectively. These results were superior to those of previously proposed clinical prediction models. The model interpretation revealed that body temperature, cough, rhinorrhea, and exposure history were positively associated with and the days of illness and influenza vaccine were negatively associated with influenza infection. We also found the week of the influenza season, pulse rate, and oxygen saturation to be associated with influenza infection.

CONCLUSIONS

The clinical feature-based ML model outperformed conventional models for predicting influenza infection.

COMMITTEE ON INFECTIOUS DISEASES, O’Leary ST, Campbell JD, Ardura MI, Banerjee R, Bryant KA, Caserta MT, Frenck RW, Gerber JS, John CC, Kourtis AP, Myers A, Pannaraj P, Ratner AJ, Shah SS, Bryant KA, Hofstetter AM, Chaparro JD, Michel JJ, Kimberlin DW, Barnett ED, Lynfield R, Sawyer MH, Bernstein HH, Cardemil CV, Farizo KM, Kafer LM, Kim D, López Medina E, Moore D, Panagiotakopoulos L, Romero JR, Sauvé L, Starke JR, Thompson J, Wharton M, Woods CR, Frantz JM, Gibbs G. Recommendations for Prevention and Control of Influenza in Children, 2023-2024

This technical report accompanies the recommendations of the American Academy of Pediatrics for the routine use of influenza vaccine and antiviral medications in the prevention and treatment of influenza in children during the 2023-2024 season. The rationale for the American Academy of Pediatrics recommendation for annual influenza vaccination of all children without medical contraindications starting at 6 months of age is provided. Influenza vaccination is an important strategy for protecting children and the broader community against influenza. This technical report summarizes recent influenza seasons, morbidity and mortality in children, vaccine effectiveness, and vaccination coverage, and provides detailed guidance on vaccine storage, administration, and implementation. The report also provides a brief background on inactivated and live-attenuated influenza vaccines, available vaccines this season, vaccination during pregnancy and breastfeeding, diagnostic testing for influenza, and antiviral medications for treatment and chemoprophylaxis. Strategies to promote vaccine uptake are emphasized.

Effectiveness of prolonged versus standard-course of oseltamivir in critically ill patients with severe influenza infection: A multicentre cohort study

The aim of this study is to investigate the effectiveness of prolonged versus standard course oseltamivir treatment among critically ill patients with severe influenza. A retrospective study of a prospectively collected database including adults with influenza infection admitted to 184 intensive care units (ICUs) in Spain from 2009 to 2018. Prolonged oseltamivir was defined if patients received the treatment beyond 5 days, whereas the standard-course group received oseltamivir for 5 days. The primary outcome was all-cause ICU mortality. Propensity score matching (PSM) was constructed, and the outcome was investigated through Cox regression and RCSs. Two thousand three hundred and ninety-seven subjects were included, of whom 1943 (81.1%) received prolonged oseltamivir and 454 (18.9%) received standard treatment. An optimal full matching algorithm was performed by matching 2171 patients, 1750 treated in the prolonged oseltamivir group and 421 controls in the standard oseltamivir group. After PSM, 387 (22.1%) patients in the prolonged oseltamivir and 119 (28.3%) patients in the standard group died (p = 0.009). After adjusting confounding factors, prolonged oseltamivir significantly reduced ICU mortality (odds ratio [OR]: 0.53, 95% confidence interval [CI]: 0.40-0.69). Prolonged oseltamivir may have protective effects on survival at Day 10 compared with a standard treatment course. Sensitivity analysis confirmed these findings. Compared with standard treatment, prolonged oseltamivir was associated with reduced ICU mortality in critically ill patients with severe influenza. Clinicians should consider extending the oseltamivir treatment duration to 10 days, particularly in higher-risk groups of prolonged viral shedding. Further randomized controlled trials are warranted to confirm these findings.

The effect of oseltamivir use in critically ill patients with COVID-19: A multicenter propensity score-matched study

Background

Oseltamivir has been used as adjunctive therapy in the management of patients with COVID-19. However, the evidence about using oseltamivir in critically ill patients with severe COVID-19 remains scarce. This study aims to evaluate the effectiveness and safety of oseltamivir in critically ill patients with COVID-19.

Methods

This multicenter, retrospective cohort study includes critically ill adult patients with COVID-19 admitted to the intensive care unit (ICU). Patients were categorized into two groups based on oseltamivir use within 48 hours of ICU admission (Oseltamivir vs. Control). The primary endpoint was viral load clearance.

Results

A total of 226 patients were matched into two groups based on their propensity score. The time to COVID-19 viral load clearance was shorter in patients who received oseltamivir (11 vs. 16 days, p = 0.042; beta coefficient: -0.84, 95%CI: (-1.33, 0.34), p = 0.0009). Mechanical ventilation (MV) duration was also shorter in patients who received oseltamivir (6.5 vs. 8.5 days, p = 0.02; beta coefficient: -0.27, 95% CI: [-0.55,0.02], P = 0.06). In addition, patients who received oseltamivir had lower odds of hospital/ventilator-acquired pneumonia (OR:0.49, 95% CI:(0.283,0.861), p = 0.01). On the other hand, there were no significant differences between the groups in the 30-day and in-hospital mortality.

Conclusion

Oseltamivir was associated with faster viral clearance and shorter MV duration without safety concerns in critically ill COVID-19 patients.

Sensitive and rapid detection of influenza A virus for disease surveillance using dual-probe electrochemical biosensor

Influenza A virus (IAV) can cause influenza, a highly infectious zoonotic respiratory disease, and early detection is essential to prevent and control its rapid spread in the population. Given the limitations of traditional detection methods in clinical laboratories, we report a large surface TPB-DVA COFs (TPB: 1,3,5-Tris(4-aminophenyl) benzene, DVA: 1,4-Benzenedicarboxaldehyd, COFs: Covalent organic frameworks) nanomaterial modified electrochemical DNA biosensor, which has dual-probe specific recognition and signal amplification. The biosensor enables quantitative detection of influenza A viruses' complementary DNA (cDNA) from 10 fM to 1 × 10³ nM (LOD = 5.42 fM) with good specificity and high selectivity. The reliability of the biosensor and portable device was verified by comparing the virus concentrations in animal tissues with those measured by digital droplet PCR (ddPCR) (P > 0.05). Moreover, the potential for influenza surveillance in this work was demonstrated by detecting the tissue samples from mice at different stages of infection. In summary, the good performance of this electrochemical DNA biosensor we proposed suggested it has the potential to be a rapid detection device for the influenza A virus, which could assist doctors or other professionals in obtaining rapid and accurate results for outbreak investigation and disease diagnosis.

Antimicrobial prescribing after rapid influenza PCR implementation in the emergency department

INTRO

Influenza shares common symptoms with bacterial pneumonia, which may result in unnecessary antibiotic prescriptions in the emergency department (ED) when the diagnosis is unknown. Rapid influenza polymerase chain reaction (PCR) tests have reduced turnaround times compared to standard multiplex PCR respiratory panels allowing for earlier diagnosis, which may improve antimicrobial stewardship outcomes in the ED. This study aims to compare antibiotic and antiviral use before and after deployment of the rapid influenza PCR in the ED.

METHODS

This single-center, retrospective, cohort study included pediatric and adult patients discharged from the ED with a positive influenza test using a standard multiplex PCR respiratory panel (January 2017 - July 2019) or rapid PCR (July 2019 - February 2020). The primary endpoint was number of antibiotic prescriptions pre- and post-implementation of the rapid influenza PCR in the ED. Secondary endpoints included number of antiviral prescriptions, duration of antimicrobial therapy, test turnaround time, ED length of stay, 30-day readmission, and adverse events. A multivariable logistic regression evaluated patient factors associated with antimicrobial prescribing.

RESULTS

A total of 620 positive influenza results were identified with 280 patients (standard multiplex PCR = 33; rapid PCR = 247) meeting inclusion criteria. Patients were less likely to be prescribed antibiotics (39.4% vs 8.9%, OR 0.15, 95% CI 0.067-0.34) and more likely to be prescribed antivirals (24.2% vs 61.1%, OR 4.92, 95% CI 2.13-11.34) with the rapid influenza PCR. Rapid influenza PCR significantly reduced ED length of stay (4.9 vs 3.4 h, p < 0.01) and test turnaround time (27 h vs 3.5 h, p < 0.01). Patients at high risk for complications associated with influenza were more likely to be prescribed antiviral therapy (22.7% vs 67.8%, OR 7.16, 95% CI 2.52-20.40). Based on the regression analysis conducted, asthma, (OR 3.5, 95% CI 1.48-8.26), immunosuppression (OR 9.6, 95% CI 1.18-78.2), and age <5 years old (OR 3.1, 95% CI 1.80-5.45) were predictors of antiviral prescribing.

CONCLUSION

Implementation of a rapid influenza PCR in the ED reduced antibiotic use and optimized antiviral therapy for patients with influenza including those at higher risk of complications.

T-705-Derived Prodrugs Show High Antiviral Efficacies against a Broad Range of Influenza A Viruses with Synergistic Effects When Combined with Oseltamivir

Emerging influenza A viruses (IAV) bear the potential to cause pandemics with unpredictable consequences for global human health. In particular, the WHO has declared avian H5 and H7 subtypes as high-risk candidates, and continuous surveillance of these viruses as well as the development of novel, broadly acting antivirals, are key for pandemic preparedness. In this study, we sought to design T-705 (Favipiravir) related inhibitors that target the RNA-dependent RNA polymerase and evaluate their antiviral efficacies against a broad range of IAVs. Therefore, we synthesized a library of derivatives of T-705 ribonucleoside analogues (called T-1106 pronucleotides) and tested their ability to inhibit both seasonal and highly pathogenic avian influenza viruses in vitro. We further showed that diphosphate (DP) prodrugs of T-1106 are potent inhibitors of H1N1, H3N2, H5N1, and H7N9 IAV replication. Importantly, in comparison to T-705, these DP derivatives achieved 5- to 10-fold higher antiviral activity and were non-cytotoxic at the therapeutically active concentrations. Moreover, our lead DP prodrug candidate showed drug synergy with the neuraminidase inhibitor oseltamivir, thus opening up another avenue for combinational antiviral therapy against IAV infections. Our findings may serve as a basis for further pre-clinical development of T-1106 prodrugs as an effective countermeasure against emerging IAVs with pandemic potential.

Assessment of the relative benefits of monotherapy and combination therapy approaches to the treatment of hospital-acquired Stenotrophomonas maltophilia pneumonia: a multicenter, observational, real-world study

PURPOSE

Stenotrophomonas maltophilia is a Gram-negative pathogen that most commonly causes hospital-acquired infections that can be extremely challenging to treat, contributing to underrecognized mortality throughout the world. The relative benefits of monotherapy as compared to combination therapy in patients diagnosed with S. maltophilia pneumonia, however, have yet to be established.

METHODS

Data from 307 patients diagnosed with S. maltophilia hospital-acquired pneumonia (HAP) across four Chinese teaching hospitals from 2016 to 2022 were retrospectively analyzed.

RESULTS

Of the analyzed patients, 55.7% (171/307) were administered combination definitive therapy, with a 30-day all-cause mortality rate of 41.0% (126/307). A propensity score weighting analysis revealed that compared with monotherapy, combination definitive therapy was associated with a comparable 30-day mortality risk in the overall patient cohort (OR 1.124, 95% CI 0.707-1.786, P = 0.622), immunocompetent patients (OR 1.349, 95% CI 0.712-2.554, P = 0.359), and patients with APACHE II scores < 15 (OR 2.357, 95% CI 0.820-6.677, P = 0.111), whereas it was associated with a decreased risk of death in immunocompromised patients (OR 0.404, 95% CI .170-0.962, P = 0.041) and individuals with APACHE II scores ≥ 15 (OR 0.494, 95% CI 0.256-0.951, P = 0.035).

CONCLUSION

The present data suggest that when treating S. maltophilia-HAP, immunocompromised patients and individuals with APACHE II scores ≥ 15 may potentially benefit from combination therapy.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Influenza presentations and use of neuraminidase inhibitors by Australian general practice registrars: a cross-sectional analysis from the ReCEnT study

OBJECTIVE

This study aims to establish prevalence and associations of (1) influenza and influenza-like illness (IILI) presentations to Australian general practice (GP) registrars (trainees) and (2) the use of neuraminidase inhibitors (NAIs) by GP registrars for new presentations of IILI, for the 10 years leading up to the COVID-19 pandemic in Australia (2010-2019).

DESIGN

This was a cross-sectional analysis of the Registrar Clinical Encounters in Training ongoing inception cohort study of the in-consultation experience and clinical behaviours of GP registrars. Data are collected by individual registrars three times (from 60 consecutive consultations each time) at 6 monthly intervals. Data include diagnoses/problems managed and medicines prescribed, along with multiple other variables. Univariate and multivariable logistic regression was used to establish associations of registrars seeing patients with IILI and of prescribing NAIs for IILI.

SETTING

Teaching practices within the Australian general practitioner specialist vocational training programme. Practices were located in five of the six Australian states (plus one territory).

PARTICIPANTS

GP registrars in each of their three compulsory 6-month GP training terms.

RESULTS

From 2010 to 2019, 0.2% of diagnoses/problems seen by registrars were IILI. 15.4% of new IILI presentations were prescribed an NAI. IILI diagnoses were less likely in younger (0-14) and older (65+) age groups, and more likely in an area of higher socioeconomic advantage. There was considerable variation in NAI prescribing between regions. There was no significant association of prescribing NAIs with age or Aboriginal and/or Torres Strait Islander patients.

CONCLUSIONS

IILI presentations were more likely among working-age adults and not among those groups at higher risk. Similarly, high-risk patient groups who would benefit most were not more likely to receive NAIs. The epidemiology and management of IILI has been distorted by the COVID-19 pandemic, but the burden of influenza in vulnerable populations must not be overlooked. Appropriately targeted antiviral therapy with NAIs influences outcomes for vulnerable patients. General practitioners manage the majority of IILI in Australia, and understanding GP IILI presentation and NAI prescribing patterns is a key first step to enabling sound and rational prescribing decisions for better patient outcomes.

Trends in Molecular Diagnosis of Nosocomial Pneumonia Classic PCR vs. Point-of-Care PCR: A Narrative Review

Nosocomial pneumonia is one of the most frequent hospital-acquired infections. One of the types of nosocomial pneumonia is ventilator-associated pneumonia, which occurs in endotracheally intubated patients in intensive care units (ICU). Ventilator-associated pneumonia may be caused by multidrug-resistant pathogens, which increase the risk of complications due to the difficulty in treating them. Pneumonia is a respiratory disease that requires targeted antimicrobial treatment initiated as early as possible to have a good outcome. For the therapy to be as specific and started sooner, diagnostic methods have evolved rapidly, becoming quicker and simpler to perform. Polymerase chain reaction (PCR) is a rapid diagnostic technique with numerous advantages compared to classic plate culture-based techniques. Researchers continue to improve diagnostic methods; thus, the newest types of PCR can be performed at the bedside, in the ICU, so-called point of care testing-PCR (POC-PCR). The purpose of this review is to highlight the benefits and drawbacks of PCR-based techniques in managing nosocomial pneumonia.