Where has all the influenza gone? The impact of COVID-19 on the circulation of influenza and other respiratory viruses, Australia, March to September 2020

Respiratory virus circulation during pandemic: Why were some viruses still circulating?

A few months after the beginning of the coronavirus disease 2019 (COVID-19) pandemic in March 2020, several non-pharmacological measures were adopted worldwide, with varying degrees of strictness, to contain the transmission of the virus and mitigate its impacts. These measures, in addition to effectively reducing the circulation of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), these measures also appeared to impact the circulation of other respiratory viruses. Therefore, this study aims to discuss the most relevant data available regarding the circulation of the major respiratory viruses during the COVID-19 pandemic, exploring the factors that allowed some viruses to continue circulating while others experienced a decline. Several authors report that the detection of influenza, respiratory syncytial virus (RSV), human coronaviruses (hCoVs), human parainfluenza viruses (HPIVs), and human metapneumovirus (hMPV) dropped significantly. However, non-enveloped viruses such as adenovirus, and especially human rhinovirus (HRV), did not seem to be as affected. Hypotheses for this scenario include adopting of non-pharmacological measures to curb the spread of COVID-19, behavioral changes in hygiene habits, intrinsic characteristics of each virus such as transmission mode, the presence or absence of a viral envelope and viral interference. Rhinovirus is particularly intriguing, as it maintained a high prevalence during the years of the pandemic. Further investigation into the possible explanations for this phenomenon may be worthwhile.

Shifts in Respiratory Virus Epidemiology on Reunion Island From 2017 to 2023: Impact of COVID-19 Pandemic and Non-Pharmaceutical Interventions

Background

The COVID‐19 pandemic has reshaped the landscape of respiratory viral infections globally. This study examines these changes on Reunion Island, a French department in the southeastern Indian Ocean.

Methods

Retrospective data from 2017 to 2023, from over 24,000 samples collected across the hospital system, partner laboratories, and a network of sentinel physicians, were analyzed and correlated with the number of consultations at the hospital emergency department and with sentinel physicians for symptoms of acute respiratory infections (ARIs). The epidemiology of respiratory viruses was analyzed by comparing the pre‐ and post‐COVID‐19 periods to assess disruptions in seasonal patterns, changes in virus prevalence, and the affected age groups.

Results

Our database effectively captured the epidemiology of respiratory infections across the island, as demonstrated by its strong correlation with the number of consultations for ARI. Post‐COVID‐19, the influenza virus exhibited multiple epidemic waves within a single year, deviating from its traditional single annual peak and showing a significant decline in circulation from 2020 to 2023. The circulation of respiratory syncytial virus was also impacted post‐COVID‐19, with epidemics starting earlier and lasting longer compared with pre‐COVID‐19 years. Human rhinovirus circulated more prominently in the post‐COVID period, accounting for up to one‐third of positive cases, becoming the most prevalent respiratory virus (excluding SARS‐CoV‐2).

Conclusions

These findings suggest a notable impact of the COVID‐19 pandemic and associated NPIs on respiratory virus circulation on Reunion Island since mid‐2020. They underscore the complex interplay between viral interference, public health interventions, behavioral changes, and youth immunity, emphasizing the need for adaptable strategies in managing respiratory virus outbreaks in the post‐COVID‐19 era.

The role of masks and respirators in preventing respiratory infections in healthcare and community settings

The covid-19 pandemic saw frequent changes and conflicts in mask policies and politicization of masks. On reviewing the evidence, including studies published after the pandemic, the data suggest respirators are more effective than masks in healthcare, but must be continuously worn to be protective. Healthcare and aged care settings amplify outbreaks, so protection of patients and staff is paramount. Most guidelines assume risk is only present during close contact or aerosol generating procedures, but studies show intermittent use of respirators is not protective. New research in aerosol science confirms the risk of infection is widespread in health facilities. In community settings, any mask use is protective during epidemics, especially if used early, when combined with hand hygiene, and if wearers are compliant. Community use of N95 respirators is more protective than surgical masks, which are more protective than cloth masks, but even cloth masks provide some protection. Mask guidelines should be adaptable to the specific context and should account for rising epidemic activity, and whether a pathogen has asymptomatic transmission. The main rationale for universal masking during pandemics is asymptomatic transmission, which means risk of transmission cannot be self-identified. The precautionary principle should be applied during serious emerging infections or pandemics when transmission mode is not fully understood, or vaccines and drugs are not available. If respirators are not available, medical or cloth masks could be used as a last resort. Data exist to support extended use and reuse of masks and respirators during short supply. In summary, extensive evidence generated during the covid-19 pandemic confirms the superiority of respirators and supports the use of masks and respirators in the community during periods of high epidemic activity. Some gaps in research remain, including economic analyses, research in special population groups for whom masking is challenging, and research on countering disinformation.

Epidemiological Transitions in Influenza Dynamics in the United States: Insights from Recent Pandemic Challenges

The SARS-CoV-2 pandemic has reshaped the epidemiological landscape of respiratory diseases, with profound implications for seasonal influenza. Nonpharmaceutical interventions implemented globally during the pandemic significantly altered human behavior and reduced the prevalence of respiratory pathogens, including influenza. However, the post-pandemic resurgence of influenza activity to pre-pandemic levels highlights the persistent challenges posed by this virus. During the 2023-2024 influenza season in the United States, an estimated 40 million individuals contracted influenza, resulting in 470,000 hospitalizations and 28,000 deaths, with the elderly disproportionately affected. Pediatric mortality was also notable, with 724 deaths reported among children. This study examines trends in influenza incidence, vaccination rates, and mortality in the United States from the 2018-2019 through to the 2023-2024 influenza seasons. Additionally, it evaluates the interplay between influenza and SARS-CoV-2 during the pandemic, considering the impact of disrupted air travel, public health measures, and altered virus circulation dynamics. By integrating these insights, the study underscores the critical need for sustained vaccination campaigns and innovative public health strategies to mitigate the dual burden of respiratory diseases. Findings from this analysis highlight the urgency of strengthening prevention and surveillance systems to enhance pandemic preparedness and reduce the impact of respiratory pathogens in an evolving epidemiological landscape.

Changes in Seasonal Patterns for Common Pediatric Respiratory Viruses During the COVID Pandemic

OBJECTIVES

Observed alterations in seasonal patterns of common pediatric respiratory viruses during and immediately after the COVID-19 pandemic had far-reaching implications for the care of ill children. Here, we quantify the effects of the pandemic and related nonpharmaceutical interventions on the prevalence and seasonality of common pediatric respiratory illnesses.

METHODS

We performed a retrospective chart review within a large health network to identify incidence rates of common respiratory viruses and compared them to historical trends. Time series analyses using seasonal autoregressive integrated moving average models were utilized to identify seasonal patterns for the different virus types and quantify deviations from expected incidence rates.

RESULTS

Overall, we noted a steep decline in non-COVID viral infection rates at the onset of the COVID pandemic in March 2020, largely coincident with the institution of mask mandates and lockdown measures. This trend continued until the Spring of 2021, at which time non-COVID infections resurged to rates higher than pre-COVID levels. In addition, the historically observed seasonality of these viruses was significantly disrupted by the pandemic. In particular, the historical peaks for influenza A and human metapneumovirus shifted from February and March, respectively, to bimodal peaks in December 2021 and May 2022; respiratory syncytial virus demonstrated an unprecedented Spring/Summer season in 2021; parainfluenza type 1 was unusually active in 2022, an even-numbered year; and influenza B virtually disappeared during and immediately after the pandemic.

CONCLUSIONS

Our observations add to the growing body of literature supporting the hypothesis that human interactions are one of the key drivers of pediatric respiratory viral seasonality in addition to climate. Understanding the effect of human interactions on disease spread is crucial for the development of effective mitigation measures for future pandemics while avoiding dangerous spikes of other illnesses once those interventions are lifted.

Assessment of the impacts of public health and social measures on influenza activity during the COVID-19 pandemic from 2020 to 2022 in Beijing, China: a modelling study

INTRODUCTION

Understanding the impact of public health and social measures (PHSMs) on influenza transmission is crucial for developing effective influenza prevention and control strategies.

METHODS

This modeling study analyzed data from 2017 to 2022, in Beijing, China. Weekly influenza positive rate and influenza-like rate were incorporated to quantify the community-level influenza activities. The effective reproduction number and influenza attack rate were estimated using a branching process model and a transmission dynamics model, respectively. The impact of PHSMs was quantified through log-linear regression and counterfactual simulations under varying PHSM scenarios.

RESULTS

The transmissibility of influenza decreased by 68.41% (95%CI: 52.43, 78.80) in 2020, 67.07% (95%CI: 50.80, 77.89) in 2021 and 79.08% (95%CI: 63.18, 88.06) in 2022, and the attack rate dropped by 93.47% (95%CI: 85.86, 95.78), 95.37% (95%CI: 94.30, 96.89) and 71.61% (95%CI: 42.96, 81.24) over the same period, primarily due to the PHSMs. The simulation shows that strict PHSMs effectively suppressed the current flu epidemic effectively. When susceptible individuals drop to 50%, a relaxed strategy results in a smaller rebound in the next flu season, with epidemic sizes increasing to 1.18 (1.10, 1.30), 1.41 (1.20, 1.54), and 1.54 (1.35, 1.55) for relaxed, moderate, and strict measures, respectively.

CONCLUSIONS

Our study confirms the suppressive effect of coronavirus disease 2019 PHSMs on influenza transmission in Beijing. However, the relaxation of these measures' triggers resurgence, emphasizing the need for adaptive control strategies tailored to the population susceptibility and epidemic dynamics.

A 32-year trend analysis of lower respiratory infections in children under 5: insights from the global burden of disease study 2021

Objectives

Lower respiratory infections are the most significant health threat to children under 5 years old, leading to the highest disease burden across all age groups. This study aims to provide an up-to-date assessment of the global burden of lower respiratory infections in children under 5 years of age.

Methods

This study utilizes data and methodologies from the Global Burden of Disease Study 2021 to analyze changes in the burden of lower respiratory infections from 1990 to 2021, focusing on incidence, mortality, and disability-adjusted life years. A jointpoint model is employed to calculate trends and the average annual percentage change in the disease burden among children under 5 years old over the period 1990-2021. Additionally, frontier analysis is used to visually depict the potential for burden reduction in each country or region based on their level of development.

Results

In 2021, the global burden of lower respiratory infections in children under 5 years old included 37,828,159 incidence cases, 501,909.50 deaths, and 44,779,174.70 disability-adjusted life years. From 1990 to 2021, the global burden of LRIs in this age group showed a marked decline. Incidence, mortality, and disability-adjusted life years decreased by 54.02, 37.57, and 39.49%, respectively. The average annual percent change for age-standardized incidence rate, age-standardized mortality rate, and age-standardized disability-adjusted life years rate were -3.35, -4.53%, and -4.52%, respectively. The disease burden was notably higher in children under 1 year old compared to those aged 2-4 years and the overall under-5 age group, with significant gender differences observed. Additionally, there was a strong negative correlation between the burden of lower respiratory infections in children under 5 and the socio-demographic index. Frontier analysis indicated that countries or regions with higher socio-demographic index values showed greater potential for reducing the burden.

Conclusion

The global burden of lower respiratory infections in children under 5 years old has declined significantly from 1990 to 2021. However, given the substantial disease burden, particularly in low-SDI countries, it is crucial to address risk factors and implement more effective interventions to further reduce the impact of lower respiratory infections on this vulnerable population.

Shifts in seasonal influenza patterns in Australia during and after COVID-19: A comprehensive analysis

BACKGROUND

During the COVID-19 pandemic, seasonal influenza virus circulation was heavily suppressed worldwide. In Australia, since the virus re-emerged in 2022, shifts in seasonal influenza patterns have been observed. Both the 2022 and 2023 seasons started earlier than pre-pandemic norms and were categorised as moderate to severe, highlighting the renewed importance of prevention strategies for seasonal influenza.

METHODS

We analysed influenza notification data from the Australian National Notifiable Diseases Surveillance System (2012-2022) and virological surveillance data from the FluNet database (2012-2023). Using generalised additive models, we compared predicted weekly influenza case counts during 2020-2022 with observed counts. Epidemic weeks were detected using a negative binomial threshold, and epidemic onset was estimated with a Bayesian Poisson count detection algorithm. Trends in epidemic magnitude and onset timing across influenza virus types and subtypes were compared for pre-, during, and post-COVID-19 periods.

RESULTS

Seasonal influenza activity was nearly absent in 2020 and 2021 but rebounded significantly in 2022 and 2023. Epidemic detection confirmed suppressed seasonal influenza circulation during the pandemic. While influenza A subtypes returned to pre-pandemic onset timings in 2022, influenza B exhibited a significantly delayed onset. The 2022 and 2023 seasons were moderate to severe, with earlier-than-average season starts, underscoring the ongoing changes in influenza dynamics post-pandemic.

CONCLUSIONS

This study provided a detailed analysis of the disruptions and subsequent shifts in seasonal influenza patterns in Australia during and after the COVID-19 pandemic. The rapid resurgence of influenza activity in 2022 and 2023, combined with altered onset timings, highlights the importance of ongoing surveillance and adaptive forecasting models to address the evolving complexity of influenza epidemiology in the post-pandemic era.

Monitoring mortality in the setting of COVID-19 pandemic control in Victoria, Australia: a time series analysis of population data

Objective

Mortality surveillance was established in the state of Victoria just before the COVID-19 pandemic. Here, we describe the establishment of this surveillance system, justify the modelling approach selected, and provide examples of how the interpretation of changes in mortality rates during the pandemic was influenced by the model chosen.

Methods

Registered deaths occurring in Victoria from 1 January 2015 to 31 December 2020 were sourced from the Victoria Death Index. Observed mortality rates were compared to a raw historical 5-year mean and to predicted means estimated from a seasonal robust regression. Differences between the observed mortality rate and the historical mean (∆MR) and excess mortality rate from the observed and predicted rates were assessed.

Results

There were 20 375 COVID-19 cases notified in Victoria as of 31 December 2020, of whom 748 (3.7%) died. Victorians aged ≥ 85 years experienced the highest case fatality ratio (34%). Mean observed mortality rates in 2020 (MR: 11.6; 95% confidence interval [CI]: 11.4, 11.9) were slightly reduced when compared with the annual rate expected using the historical mean method (mean MR: 12.2; 95% CI: 12.1-12.3; ∆MR: -0.57; 95% CI: -0.77, -0.38), but not from the rate expected using the robust regression (estimated MR: 11.7; 95% prediction interval [PI]: 11.5, 11.9; EMR: -0.05; 95% CI: -0.26, 0.16). The two methods yielded opposing interpretations for some causes, including cardiovascular and cancer mortality.

Discussion

Interpretation of how pandemic restrictions impacted mortality in Victoria in 2020 is influenced by the method of estimation. Time-series approaches are preferential because they account for population trends in mortality over time.

Epidemiological characteristics of eleven common respiratory viral infections in children

BACKGROUND

Lower respiratory tract infections (LRTIs) are one of the leading causes of hospital admissions among children. In this study, we aimed to describe the epidemiological characteristics of viral pathogens associated with LRTIs in hospitalized children in Yan'an; this has yet to be reported in the literature and may guide public health interventions and resource allocation in this region.

METHODS

Between June 2021 and May 2023, we conducted a retrospective analysis of the results of viral detection using oral pharyngeal swabs from 4565 children with LRTIs in the Inpatient Department of Yan'an University Affiliated Hospital. Eleven respiratory viruses, including influenza A virus (Flu A), influenza A H1N1 virus (H1N1), seasonal influenza A H3N2 virus (H3N2), influenza B virus (Flu B), parainfluenza virus (HPIV), adenovirus (HADV), bocavirus (HBoV), rhinovirus (HRV), metapneumovirus (HNPV), coronavirus (HCoV), and respiratory syncytial virus (HRSV), were confirmed by applying a multiplex real-time polymerase chain reaction (PCR) kit for respiratory viruses. We evaluated the epidemiological features of infections caused by respiratory pathogens, including aging, gender and the seasonal variations of different pathogens, and explored the high-risk factors associated with virus-caused pneumonia.

RESULTS

At least one virus was detected in all 4565 cases; the positivity rate was 27.95%. We also detected a total of 1,276 cases with mixed infections (with two or more viruses). Of the positive cases, 59.3% were male and 40.7% were female (x2 = 0.41, P = 0.68). The highest positivity rates for respiratory pathogens were observed for HRSV, HRV, and HADV, at 5.98%, 5.67%, and 4.38%, respectively. We also observed variations in the number and positivity rates of respiratory pathogen infections by season, age and gender. HPIV (x2 = 12.05, P < 0.05) and HADV (x2 = 11.73, P < 0.05) were more common in children under three years-of-age. Notably, with the exception of the 1 to < 3 years age group, males consistently demonstrated elevated infection rates across other age groups.

CONCLUSIONS

Our analysis revealed that respiratory pathogen infections varied by gender, season, and age in the enrolled population of children.

Irregular seasonality of respiratory syncytial virus infection persists in 2023 in Osaka, Japan

Objectives

Owing to the nonpharmaceutical interventions against COVID-19, respiratory syncytial virus (RSV) infection was nearly absent in 2020. An unusual epidemic size and irregular seasonal pattern were observed worldwide in 2021. In Osaka, Japan, after disrupting the regular pattern of RSV infection dynamics (before the COVID-19 pandemic, RSV epidemics typically start in summer and peak around fall), the epidemic size of RSV infection returned to normal in 2022. However, the epidemic onset timing remained irregular in 2022 and 2023. This study investigated whether the onset of the RSV infection epidemic in 2023 was predictable using previous seasonal patterns.

Methods

The weekly number of RSV infection cases obtained from sentinel pediatric sites between 2007 and the 15th week of 2023 was modeled using the time series susceptible-infected-recovered model. Forecasting of the remainder of 2023 was conducted based on estimated transmission parameters.

Results

None of the estimated transmission rates from previous years successfully forecast the epidemic onset in 2023. Only the transmission rate estimated in the early part of 2023 captured the trend for that year, indicating irregular seasonal transmission rates.

Conclusions

It is still hard to forecast RSV epidemics because of the changed landscape due to the COVID-19 pandemic. The seasonality of RSV infection dynamics has not returned to pre-pandemic level in 2023. Cautious attention to future RSV dynamics in Japan is warranted because further changes may occur in the near future.

Changes in entire acute bronchiolitis seasons before, during, and after the COVID-19 pandemic in Spain

Background

Paediatric acute bronchiolitis normally occurs from October to April in the temperate northern hemisphere, peaking in January. Nonpharmacological measures to control the spread of COVID-19 resulted in a decrease in the number of cases of bronchiolitis during the 2020-21 season. The discontinuation of these measures created an uncertain scenario.

Aim

To describe the epidemiological evolution of acute bronchiolitis seasons and the changes in the demographics of the affected population before, during, and after the implementation of nonpharmacological interventions for COVID-19 in Spain.

Methods

This was a multicentre and descriptive study. A total of 6,334 infants aged up to 12 months who were diagnosed with acute bronchiolitis were recruited from sixteen Spanish hospitals. We collected data from participants from September 1st, 2021, through August 31st, 2023, as part of the ECEALHBA research project. The study periods were before (P1), during (P2), and after (P3) the COVID-19 pandemic.

Findings

In P2 and after the discontinuation of nonpharmacological interventions, an unexpected increase in the number of acute bronchiolitis cases was observed from June-August 2021, resulting in an out-of-season peak. A subsequent peak was observed in November 2021, earlier than expected for the 2021-22 season. In the 2022-23 season, admissions followed a historical trend, with a greater number of cases than in the two previous seasons. Statistically significant differences in the length of stay (p<0.001), number of RSV infections (p=0.021), and number of paediatric intensive care unit admissions (p<0.001) were observed among the periods.

Conclusions

Two out-of-season peaks in the number of acute bronchiolitis cases were observed in 2020-2021 and 2021-2022. However, following the relaxation of nonpharmacological intervention measures, the peak observed in 2022-2023, although occurring 2-6 weeks earlier, was more similar to the peaks observed in the prepandemic seasons. Additionally, increased case severity was observed during these periods.

Rhinovirus infection and co-infection in children with severe acute respiratory infection during the COVID-19 pandemic period

Rhinovirus causes respiratory tract infections in children and is found in co-infections. The objective of this research was to study the clinical profile of rhinovirus infection and co-infection in children with severe acute respiratory infection (SARI) during the COVID-19 pandemic period. We included 606 children ranging in age from 0.1 to 144 months of age from March 2020 to December 2021, hospitalized in the Pediatric Intensive Care Unit (PICU). The samples were collected by secretion from the nasopharynx region. A total of 259 children were tested positive for viral infection, 153 (59.07%) of them had a single rhinovirus infection and, 56 (36.6%) were aged between 60.1 and 144 months. Nine types of co-infections were identified and were found coinfection with three or more viruses (22/104, 21.15%). Observing the seasonality, the number of cases was similar between 2020 (49.53%) and 2021 (51.47%). Patients with a single infection (86.88%) and coinfection (67.30%) were more likely to have coughed. Patients with co-infection required the use of O2 for longer than those with a single rhinovirus infection. Hemogram results obtained from individuals with a single infection had higher levels of urea when compared to patients with co-infection with and other respiratory viruses. Multiple correspondence analyses indicated different clinical symptoms and comorbidities in patients with co-infection compared to those with single infection. The results found that the rhinovirus was much prevalent virus during the pandemic period and was found in co-infection with other virus types, what is important to diagnostic for the correct treatment of patients.

Epidemiological characteristics of respiratory pathogens infections among children after the removal of non-pharmaceutical interventions in central China

BACKGROUND

During the COVID-19 pandemic between 2020 and 2022 in China, various non-pharmaceutical interventions (NPIs) were implemented to reduce the spread of SARS-CoV-2 and other respiratory pathogens. From 2023, China downgraded the management of COVID-19, and compliance with NPIs was no longer mandatory. This study aimed to reveal the epidemiological characteristics of respiratory pathogens in 2023 after the removal of NPIs in central China.

METHODS

Respiratory specimens of children with acute respiratory infections (ARIs) were obtained to detect seven common respiratory pathogens, including influenza A (FluA), influenza B (FluB), adenovirus (ADV), human rhinovirus (HRV), human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), Mycoplasma pneumoniae (MP). From January 2022 to December 2023, a total of 5423 specimens were collected, including 1122 children in 2022 and 4301 children in 2023.

RESULTS

One or more pathogens were detected in 62.50% specimens in 2023, significantly higher than that in 2022 (44.12%). HRV (13.81%) was the most common pathogen in 2022, whereas MP (24.67%) was predominant in 2023. There was no significant difference in the overall prevalence of HRV, HRSV and HMPV between 2022 and 2023. HRSV was the most common pathogen in the < 1 years children both in 2022 and 2023. However in the ≥ 7 years group, FluB was the predominant pathogen in 2022 whereas MP ranked first in 2023. Co-detection were significantly more frequent in 2023 compared to 2022.

CONCLUSIONS

The removal of NPIs significantly increased the infection rates of the respiratory pathogens among children. Some NPIs, such as wearing mask and hand hygiene are necessary to decrease the prevalence of certain pathogens.

Respiratory Disease Surveillance in the Middle East and Latin America during the COVID-19 Pandemic, 2020-2022

Characterizing the epidemiology of circulating respiratory pathogens during the COVID-19 pandemic could clarify the burden of acute respiratory infections and monitor outbreaks of public health and military relevance. The US Department of Defense supported 2 regions for influenza-like illness and severe acute respiratory infections surveillance, one in the Middle East through US Naval Medical Research Unit EURAFCENT, and another in Latin America through US Naval Medical Research Unit SOUTH. During 2020‒2022, coinciding with the COVID-19 pandemic, we collected a total of 16,146 nasopharyngeal and oropharyngeal swab samples from sentinel sites in Jordan (n = 11,305) and Latin America (n = 4,841). Samples were tested for SARS-CoV-2, influenza, and other respiratory pathogens. SARS-CoV-2 was the most frequently detected pathogen during 2020; other respiratory pathogens had distinct temporal and frequency distributions according to geographic location. Our findings support the need for continued sentinel surveillance as a vital tool for assessing the burden of respiratory diseases globally.

Impact of COVID-19 on the Prevalence and Drug Resistance of Bacteria Isolated From Bacterial Meningitis Cerebrospinal Fluid in Shandong Province: A Multicenter Retrospective Study

Our objective was to evaluate the ramifications of the 2019 coronavirus disease (COVID-19) pandemic on the microbial profile and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid (CSF) specimens of patients with bacterial meningitis. We conducted a retrospective analysis of laboratory results and clinical records about positive CSF cultures reported by the SPARSS network from 2017 to 2023. The study covered three distinct periods: January 2017 to December 2019 (before the COVID-19 pandemic), January 2020 to December 2022 (during the COVID-19 pandemic), and January 2023 to December 2023 (after the COVID-19 pandemic), with a total of 5793 CSF isolates collected. Notably, the proportion of male patients (61.3%) was higher than that of females. After COVID-19, we observed a notable shift in the seasonal peak of CSF pathogens, with a delay of approximately 3 months. Remarkable alterations were evident in both pediatric and adult CSF isolate profiles. In children, the predominant pathogens included coagulase-negative Staphylococcus (CoNS), Streptococcus pneumonia, and Escherichia coli. Notably. After COVID-19, there was a significant decrease in the proportion of CoNS (p = 0.0039) and a notable increase in E. coli (p = 0.0067). In adults, the top three pathogens were CoNS, Acinetobacter baumannii, and Klebsiella pneumoniae. After the pandemic, we observed a significant reduction in the prevalence of A. baumannii (p = 0.0059), while the proportions of K. pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis increased significantly (p < 0.05). Additionally, among multidrug-resistant bacteria, the detection rate of carbapenem-resistant E. coli escalated (p = 0.0375). Antimicrobial susceptibility analysis indicated a declining trend in resistance rates for CoNS and A. baumannii to certain antibiotics following the pandemic. Conversely, resistance to imipenem in A. baumannii increased. In conclusion, the COVID-19 pandemic has significantly influenced the composition, antimicrobial resistance patterns, and epidemiological dynamics of CSF-isolated bacteria in Shandong province. To effectively address these changes, ongoing and dynamic surveillance of pathogen trends and antimicrobial resistance rate is essential.

The impact of the COVID-19 pandemic on RSV outbreaks in children: A multicenter study from China

OBJECTIVE

The aim of the study is to describe the season of RSV prevalence in China during the COVID-19 pandemic.

METHODS

This multicenter retrospective study analyzed the epidemiology of pediatric RSV infections and the possible factors contributing to its variations in China from January 1, 2019, to October 31, 2022.

RESULTS

A total of 872,565 children were included. During the pandemic, RSV detection rate increased across various regions, including South China, East China, Central China, and Northeast China. From 2019 to 2021, the detection rates of RSV showed an increasing trend among children aged <1 year, 1-2 years, and 3-5 years, but decreased in 2022. Among those tested positive for RSV, the proportion of children under 1 year old significantly decreased during the pandemic. The spring season of RSV in China in 2020 was shortened, and most regions experienced a summer season of RSV in 2021. This shift led to a year-round RSV outbreak throughout 2021. After April 2022, RSV positive rate significantly decreased, and no clear seasonal pattern was observed.

CONCLUSION

Our study found that the COVID-19 pandemic has disrupted the seasonal pattern of RSV outbreaks in China, leading to increased RSV positive rate and off-season outbreaks.

Advanced federated ensemble internet of learning approach for cloud based medical healthcare monitoring system

Medical image machines serve as a valuable tool to monitor and diagnose a variety of diseases. However, manual and centralized interpretation are both error-prone and time-consuming due to malicious attacks. Numerous diagnostic algorithms have been developed to improve precision and prevent poisoning attacks by integrating symptoms, test methods, and imaging data. But in today's digital technology world, it is necessary to have a global cloud-based diagnostic artificial intelligence model that is efficient in diagnosis and preventing poisoning attacks and might be used for multiple purposes. We propose the Healthcare Federated Ensemble Internet of Learning Cloud Doctor System (FDEIoL) model, which integrates different Internet of Things (IoT) devices to provide precise and accurate interpretation without poisoning attack problems, thereby facilitating IoT-enabled remote patient monitoring for smart healthcare systems. Furthermore, the FDEIoL system model uses a federated ensemble learning strategy to provide an automatic, up-to-date global prediction model based on input local models from the medical specialist. This assures biomedical security by safeguarding patient data and preserving the integrity of diagnostic processes. The FDEIoL system model utilizes local model feature selection to discriminate between malicious and non-malicious local models, and ensemble strategies use positive and negative samples to optimize the performance of the test dataset, enhancing its capability for remote patient monitoring. The FDEIoL system model achieved an exceptional accuracy rate of 99.24% on the Chest X-ray dataset and 99.0% on the MRI dataset of brain tumors compared to centralized models, demonstrating its ability for precision diagnosis in IoT-enabled healthcare systems.

Increased Incidence of Rhinovirus Pneumonia in Children During the COVID-19 Pandemic in Mexico

Background: Human rhinovirus (HRV), traditionally recognized as the primary etiological agent of the common cold, has become the second most important viral agent in bronchopulmonary conditions, such as pneumonia and asthma exacerbations. During the COVID-19 pandemic, several viruses exhibited changes in their epidemiological behavior. This study aims to evaluate the clinical and epidemiological characteristics of children with HRV pneumonia before and during the pandemic in Mexico. Methods: A comparative ambispective longitudinal epidemiological study of two cohorts (prepandemic and pandemic periods) was carried out. Two databases were compared: one from 2010 to 2013 and the other from 2021 to 2023. Children under 5 years of age diagnosed with HRV pneumonia were included. Student's t-test, χ 2 tests, and logistic regression were used to assess risk factors associated with severe pneumonia. Incidence density was calculated as HRV cases per 10 new cases of pneumonia per month for each year. Results: During the pandemic, the age of presentation shifted from 5 months to 16 months. There was a higher incidence of HRV pneumonia in children during the pandemic, particularly in the second half of 2021, with a peak in July and August. In addition, there was an increase in severity (53% vs. 63%, p=0.006) and coinfections (51.3% vs. 76% p < 0.001). A higher prevalence of all risk factors was observed in the second cohort. Conclusions: During the pandemic, a shift toward older age, a higher percentage of coinfections, and increased severity associated to HRV pneumonia were observed. These findings highlight the need for the development and implementation of targeted prevention and treatment measures for HRV.

Ocular Adverse Events After Influenza Vaccination in Older Adults: Self-Controlled Case Series Using a Large Database in Japan

BACKGROUND

To clarify the risk of adverse ocular events following influenza vaccination.

METHODS

This self-controlled case series study used a claims database linked to vaccination records of a large city in Japan between April 2014 and September 2021. Individuals aged ≥ 65 years who developed adverse ocular events during the follow-up period were included. The exposure was influenza vaccination. The primary outcome was defined as the occurrence of at least one of the following five eye diseases: uveitis, scleritis, retinal vein occlusion, retinal artery occlusion, or optic neuritis. Conditional Poisson regression was used to estimate the within-subject incidence rate ratio of ocular adverse events during the risk period (0-56 days after vaccination) compared to the control period.

RESULTS

A total of 4,527 cases were eligible for the study (median age, 74 years; male, 42%). The incidence rate ratio for the outcome during the risk period was 0.99 (95% confidence interval, 0.87 to 1.14). No increased risk was observed for individual components of the outcome either; the incidence rate ratio was 0.94 (0.78 to 1.13) for uveitis, 1.17 (0.86 to 1.59) for scleritis, 0.98 (0.76 to 1.27) for retinal vein occlusion, 0.89 (0.42 to 1.87) for retinal artery occlusion, and 0.87 (0.44 to 1.70) for optic neuritis.

CONCLUSIONS

This self-controlled case series showed no apparent increase in the risk of adverse ocular events after influenza vaccination among older adults. These results mitigate the concerns of older adults who may hesitate to receive influenza vaccination for fear of adverse ocular events.

ABBREVIATION

HR = hazard ratio; CI = confidence interval; RVO = retinal vein occlusion; SCCS = self-controlled case series.

The Effect of Mask Use on Seasonal Virus Diversity in SARS CoV-2 Negative Patients Treated as Inpatients During the 2021-2022 and 2022-2023 Seasonal Flu Period

The study aimed to explore the protective effect of mask use against respiratory tract viral agents during the pandemic. The study included patients with a COVID-19 negative test who were hospitalized in the pulmonary disease clinic with the diagnoses of asthma attack, chronic obstructive pulmonary disease (COPD) exacerbation, and pneumonia in two periods: during mandatory mask use (October 2021 - May 2022) and after the mask mandate was lifted (October 2022 - May 2023). Combined nose and throat swab samples taken from the patients were evaluated for viral agents by using the PCR test method. Viral agents isolated from the patients in the two periods were compared based on hospitalization diagnoses and periods. The study enrolled 1,335 patients, 483 female and 852 male. It was found that viral agents significantly increased during the period without a mask mandate compared to the period when the mask mandate was in effect (41.6% vs. 23.4%) (p < 0.001). During the period without mask mandate, influenza A, H1N1, and RSV/AB viruses significantly increased (p = 0.019, p = 0.003, p < 0.001, respectively). Our results indicated that mask use during the pandemic is protective against the transmission of respiratory tract viruses. Thus, it can be concluded that mask use is important not only in the coronavirus pandemic but also especially in influenza and RSV epidemics.

Internet-based Surveillance Systems and Infectious Diseases Prediction: An Updated Review of the Last 10 Years and Lessons from the COVID-19 Pandemic

The last decade has seen major advances and growth in internet-based surveillance for infectious diseases through advanced computational capacity, growing adoption of smart devices, increased availability of Artificial Intelligence (AI), alongside environmental pressures including climate and land use change contributing to increased threat and spread of pandemics and emerging infectious diseases. With the increasing burden of infectious diseases and the COVID-19 pandemic, the need for developing novel technologies and integrating internet-based data approaches to improving infectious disease surveillance is greater than ever. In this systematic review, we searched the scientific literature for research on internet-based or digital surveillance for influenza, dengue fever and COVID-19 from 2013 to 2023. We have provided an overview of recent internet-based surveillance research for emerging infectious diseases (EID), describing changes in the digital landscape, with recommendations for future research directed at public health policymakers, healthcare providers, and government health departments to enhance traditional surveillance for detecting, monitoring, reporting, and responding to influenza, dengue, and COVID-19.

Global, regional, and national incidence and mortality burden of non-COVID-19 lower respiratory infections and aetiologies, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021

BACKGROUND

Lower respiratory infections (LRIs) are a major global contributor to morbidity and mortality. In 2020-21, non-pharmaceutical interventions associated with the COVID-19 pandemic reduced not only the transmission of SARS-CoV-2, but also the transmission of other LRI pathogens. Tracking LRI incidence and mortality, as well as the pathogens responsible, can guide health-system responses and funding priorities to reduce future burden. We present estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 of the burden of non-COVID-19 LRIs and corresponding aetiologies from 1990 to 2021, inclusive of pandemic effects on the incidence and mortality of select respiratory viruses, globally, regionally, and for 204 countries and territories.

METHODS

We estimated mortality, incidence, and aetiology attribution for LRI, defined by the GBD as pneumonia or bronchiolitis, not inclusive of COVID-19. We analysed 26 259 site-years of mortality data using the Cause of Death Ensemble model to estimate LRI mortality rates. We analysed all available age-specific and sex-specific data sources, including published literature identified by a systematic review, as well as household surveys, hospital admissions, health insurance claims, and LRI mortality estimates, to generate internally consistent estimates of incidence and prevalence using DisMod-MR 2.1. For aetiology estimation, we analysed multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature data using a network analysis model to produce the proportion of LRI deaths and episodes attributable to the following pathogens: Acinetobacter baumannii, Chlamydia spp, Enterobacter spp, Escherichia coli, fungi, group B streptococcus, Haemophilus influenzae, influenza viruses, Klebsiella pneumoniae, Legionella spp, Mycoplasma spp, polymicrobial infections, Pseudomonas aeruginosa, respiratory syncytial virus (RSV), Staphylococcus aureus, Streptococcus pneumoniae, and other viruses (ie, the aggregate of all viruses studied except influenza and RSV), as well as a residual category of other bacterial pathogens.

FINDINGS

Globally, in 2021, we estimated 344 million (95% uncertainty interval [UI] 325-364) incident episodes of LRI, or 4350 episodes (4120-4610) per 100 000 population, and 2·18 million deaths (1·98-2·36), or 27·7 deaths (25·1-29·9) per 100 000. 502 000 deaths (406 000-611 000) were in children younger than 5 years, among which 254 000 deaths (197 000-320 000) occurred in countries with a low Socio-demographic Index. Of the 18 modelled pathogen categories in 2021, S pneumoniae was responsible for the highest proportions of LRI episodes and deaths, with an estimated 97·9 million (92·1-104·0) episodes and 505 000 deaths (454 000-555 000) globally. The pathogens responsible for the second and third highest episode counts globally were other viral aetiologies (46·4 million [43·6-49·3] episodes) and Mycoplasma spp (25·3 million [23·5-27·2]), while those responsible for the second and third highest death counts were S aureus (424 000 [380 000-459 000]) and K pneumoniae (176 000 [158 000-194 000]). From 1990 to 2019, the global all-age non-COVID-19 LRI mortality rate declined by 41·7% (35·9-46·9), from 56·5 deaths (51·3-61·9) to 32·9 deaths (29·9-35·4) per 100 000. From 2019 to 2021, during the COVID-19 pandemic and implementation of associated non-pharmaceutical interventions, we estimated a 16·0% (13·1-18·6) decline in the global all-age non-COVID-19 LRI mortality rate, largely accounted for by a 71·8% (63·8-78·9) decline in the number of influenza deaths and a 66·7% (56·6-75·3) decline in the number of RSV deaths.

INTERPRETATION

Substantial progress has been made in reducing LRI mortality, but the burden remains high, especially in low-income and middle-income countries. During the COVID-19 pandemic, with its associated non-pharmaceutical interventions, global incident LRI cases and mortality attributable to influenza and RSV declined substantially. Expanding access to health-care services and vaccines, including S pneumoniae, H influenzae type B, and novel RSV vaccines, along with new low-cost interventions against S aureus, could mitigate the LRI burden and prevent transmission of LRI-causing pathogens.

FUNDING

Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care (UK).

Molecular epidemiology and phylogenetic analysis of influenza viruses A (H3N2) and B/Victoria during the COVID-19 pandemic in Guangdong, China

BACKGROUND

Non-pharmaceutical measures and travel restrictions have halted the spread of coronavirus disease 2019 (COVID-19) and influenza. Nonetheless, with COVID-19 restrictions lifted, an unanticipated outbreak of the influenza B/Victoria virus in late 2021 and another influenza H3N2 outbreak in mid-2022 occurred in Guangdong, southern China. The mechanism underlying this phenomenon remains unknown. To better prepare for potential influenza outbreaks during COVID-19 pandemic, we studied the molecular epidemiology and phylogenetics of influenza A(H3N2) and B/Victoria that circulated during the COVID-19 pandemic in this region.

METHODS

From January 1, 2018 to December 31, 2022, we collected throat swabs from 173,401 patients in Guangdong who had acute respiratory tract infections. Influenza viruses in the samples were tested using reverse transcription-polymerase chain reaction, followed by subtype identification and sequencing of hemagglutinin (HA) and neuraminidase (NA) genes. Phylogenetic and genetic diversity analyses were performed on both genes from 403 samples. A rigorous molecular clock was aligned with the phylogenetic tree to measure the rate of viral evolution and the root-to-tip distance within strains in different years was assessed using regression curve models to determine the correlation.

RESULTS

During the early period of COVID-19 control, various influenza viruses were nearly undetectable in respiratory specimens. When control measures were relaxed in January 2020, the influenza infection rate peaked at 4.94% (39/789) in December 2021, with the influenza B/Victoria accounting for 87.18% (34/39) of the total influenza cases. Six months later, the influenza infection rate again increased and peaked at 11.34% (255/2248) in June 2022; influenza A/H3N2 accounted for 94.51% (241/255) of the total influenza cases in autumn 2022. The diverse geographic distribution of HA genes of B/Victoria and A/H3N2 had drastically reduced, and most strains originated from China. The rate of B/Victoria HA evolution (3.11 × 10-3, P < 0.05) was 1.7 times faster than before the COVID-19 outbreak (1.80 × 10-3, P < 0.05). Likewise, the H3N2 HA gene's evolution rate was 7.96 × 10-3 (P < 0.05), which is 2.1 times faster than the strains' pre-COVID-19 evolution rate (3.81 × 10-3, P < 0.05).

CONCLUSIONS

Despite the extraordinarily low detection rate of influenza infection, concealed influenza transmission may occur between individuals during strict COVID-19 control. This ultimately leads to the accumulation of viral mutations and accelerated evolution of H3N2 and B/Victoria viruses. Monitoring the evolution of influenza may provide insights and alerts regarding potential epidemics in the future.

Surveillance of respiratory viruses by aerosol screening in indoor air as an early warning system for epidemics

The development of effective methods for the surveillance of seasonal respiratory viruses is required for the timely management of outbreaks. We aimed to survey Influenza-A, Influenza-B, RSV-A, Rhinovirus and SARS-CoV-2 surveillance in a tertiary hospital and a campus over 5 months. The effectiveness of air screening as an early warning system for respiratory viruses was evaluated in correlation with respiratory tract panel test results. The overall viral positivity was higher on the campus than in the hospital (55.0% vs. 38.0%). Influenza A was the most prevalent pathogen in both locations. There were two influenza peaks (42nd and 49th weeks) in the hospital air, and a delayed peak was detected on campus in the 1st-week of January. Panel tests indicated a high rate of Influenza A in late December. RSV-A-positivity was higher on the campus than the hospital (21.6% vs. 7.4%). Moreover, we detected two RSV-A peaks in the campus air (48th and 51st weeks) but only one peak in the hospital and panel tests (week 49). Although rhinovirus was the most common pathogen in panel tests, rhinovirus positivity was low in air samples. The air screening for Influenza-B and SARS-Cov-2 revealed comparable positivity rates with panel tests. Air screening can be integrated into surveillance programs to support infection control programs for potential epidemics of respiratory virus infections except for rhinoviruses.

Epidemiology and viral loads of respiratory syncytial virus in hospitalized children prior to and during COVID-19 pandemic in Hangzhou, China

Non-pharmaceutical interventions (NPIs) implemented to control SARS-CoV-2 have significantly influenced the activity of respiratory pathogens. This study investigated epidemiological changes among hospitalized patients with respiratory syncytial virus (RSV) before (2017-2019) and during (2020-2022) the COVID-19 pandemic in Hangzhou, China. We also examined viral load distribution across demographic and temporal variables. Nasopharyngeal swabs were collected and RSV loads were quantified using reverse transcriptase polymerase chain reaction (RT-qPCR). RSV epidemic characteristics, seasonal dynamics, and viral load distributions were compared between pre- and pandemic years. General linear models were employed to assess associations between viral loads and age. Among 19 742 cases, 1576 and 2092 tested positive during the pre- and pandemic years, respectively. From February to July 2020, the implementation of NPIs led to the cessation of RSV circulation. However, after these measures were relaxed, RSV cases resurged over two consecutive seasons during the pandemic, notably affecting older children compared to those in the pre-pandemic years (1.00 years, IQR: 0.50-2.00 vs. 0.58 years, IQR: 0.27-1.00, p < 0.001). Specifically, in 2021-2022, an off-season resurgence of RSV began earlier (mid-June), lasted longer (40 weeks), and involved more positive cases (1238 cases) than both 2020-2021 and pre-pandemic years. Viral load distribution demonstrated a clear age-related relationship in both pre- and pandemic years, with younger children consistently showing higher viral loads, independently of gender and season (all p-values for trends <0.001). These findings highlight the impact of NPIs on RSV epidemiology and underscore the need to prioritize RSV infection prevention in younger children from the perspective of viral load.

COVID-19 restrictions limited interactions of people and resulted in lowered E. coli antimicrobial resistance rates

Background

Antibiotic resistance is rising globally and is a major One Health problem. How much person-to-person transmission or 'contagion' contributes to the spread of resistant strains compared with antibiotic usage remains unclear. As part of its COVID-19 response, Australia introduced strict people movement restrictions in early 2020. Along with internal lockdown measures, movement of people into Australia from overseas was severely restricted. These circumstances provided a unique opportunity to examine the association of people movements with changes in resistance rates.

Methods

Monthly resistance data on over 646 000 Escherichia coli urine isolates from 2016 till 2023 were modelled for statistical changes in resistance trends during pre-lockdown, lockdown and post-lockdown periods. Data were available for three clinical contexts (community, hospital and aged-care facilities). Data were also available for antibiotic usage volumes and movements of people into Australia.

Results

In 2020, arrivals into Australia decreased by >95%. Antibiotic community use fell by >20%. There were sharp falls in trend rates of resistance for all antibiotics examined after restrictions were instituted. This fall in trend rates of resistance persisted during restrictions. Notably, trend rates of resistance fell in all three clinical contexts. After removal of restrictions, an upsurge in trend rates of resistance was seen for nearly all antibiotics but with no matching upsurge in antibiotic use.

Conclusions

Restricting the movement of people appeared to have a dramatic effect on resistance rates in E. coli. The resulting reduced person-to-person interactions seems more closely associated with changes in antibiotic resistance than antibiotic usage patterns.

A significant outbreak of respiratory human adenovirus infections among children aged 3-6 years in Hokkaido, Japan, in 2023

Human adenovirus (HAdV) infections present diverse clinical manifestations upon infecting individuals, with respiratory infections predominating in children. We surveyed pediatric hospitalizations due to respiratory HAdV infections across 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to March 2024, recording 473 admissions. While hospitalizations remained below five cases per week from July 2019 to September 2023, a notable surge occurred in late October 2023, with weekly admissions peaking at 15-20 cases from November to December. There were dramatic shifts in the age distribution of hospitalized patients: during 2019-2021, 1-year-old infants and children aged 3-6 years represented 51.4%-54.8% and 4.1%-13.3%, respectively; however, in 2023-2024, while 1-year-old infants represented 19.0%-20.1%, the proportion of children aged 3-6 years increased to 46.2%-50.0%. Understanding the emergence of significant outbreaks of respiratory HAdV infections and the substantial changes in the age distribution of hospitalized cases necessitates further investigation into the circulating types of HAdV in Hokkaido Prefecture and changes in children's neutralizing antibody titers against HAdV.

Molecular Genotyping of Circulating Enterovirus in the Lazio Region from 2012 to 2023

Enteroviruses (EVs) are ubiquitous viruses that circulate worldwide, causing sporadic or epidemic infections, typically during the summer and fall. They cause a broad spectrum of illnesses, ranging from an unspecified febrile clinical presentation to a severe illness. EVs are recognized to be the most frequent etiological agents of aseptic meningitis in children. However, as the infection is usually mild and self-limiting, it remains underestimated, and the epidemiology of EVs is poorly understood. To date, no vaccine or effective therapy for all types of enteroviruses is available, and EVs constitute a public health concern. Here, we investigated the molecular epidemiology of EV strains circulating in the Lazio region over a 10-year time span (2012-2023) by using a sequence-typing approach and phylogenetic analysis. The epidemiological trend of EV infection has undergone changes during the SARS-CoV-2 pandemic (2020-2021), which resulted in a modification in terms of the number of diagnosed cases and seasonality. From 2022, the circulation of EVs showed a behavior typical of the pre-pandemic period, although changes in predominantly circulating strains have been noted. Both epidemic and sporadic circulation events have been characterized in the Lazio region. Further analyses are needed to better characterize any strain with higher potential pathogenic power and to identify possible recombinant strains.

Mycoplasma pneumoniae detections in children with lower respiratory infection before and during the COVID-19 pandemic: a large sample study in China from 2019 to 2022

BACKGROUND

Nonpharmaceutical interventions (NPIs) implemented to reduce the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have suppressed the spread of other respiratory viruses during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to explore the epidemiological trends and clinical characteristics of Mycoplasma pneumoniae (MP) infection among inpatient children with lower respiratory tract infection (LRTI) before and during the COVID-19 pandemic, and investigate the long-term effects of China's NPIs against COVID-19 on the epidemiology of MP among inpatient children with LRTI.

METHODS

Children hospitalised for LRTI at the Department of Pulmonology, The Children's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between January 2019 and December 2022 were tested for common respiratory pathogens, including Mycoplasma pneumoniae (MP), Chlamydia trachomatis (CT) and other bacteria. Clinical data on age, sex, season of onset, disease spectrum, and combined infection in children with MP-induced LRTI in the past 4 years were collected and analysed.

RESULTS

Overall, 15909 patients were enrolled, and MP-positive cases were 1971 (34.0%), 73 (2.4%), 176 (5.8%), and 952 (20.6%) in 2019, 2020, 2021, and 2022, respectively, with a significant statistical difference in the MP-positive rate over the 4 years (p <0.001). The median age of these children was preschool age (3-6 years), except for 2022, when they were school age (7-12 years), with statistical differences. Comparing the positive rates of different age groups, the school-age children (7-12 years) had the highest positive rate, followed by the preschoolers (3-6 years) in each of the 4 years. Compared among different seasons, the positive rate of MP in children with LRTI was higher in summer and autumn, whereas in 2020, it was highest in spring. The monthly positive rate peaked in July 2019, remained low from 2020 to 2021, and rebounded until 2022. Regarding the disease spectrum, severe pneumonia accounted for the highest proportion (46.3%) pre-pandemic and lowest (0%) in 2020.

CONCLUSION

Trends in MP detection in children with LRTIs suggest a possible correlation between COVID-19 NPIs and significantly reduced detection rates. The positivity rate of MP gradually rose after 2 years. The epidemic season showed some differences, but school-age children were more susceptible to MP before and during the COVID-19 pandemic.

Impact of the COVID-19 pandemic on infectious diseases reporting

Introduction

COVID-19 pandemic had impacted the reporting of notifiable communicable diseases. Since the beginning of the pandemic and the introduction of relate public health measures, notifications for most notifiable diseases have declined compared to previous years. In this study, we aim to quantify the changes in the incidences of notifiable infectious diseases during and after the pandemic in Siracusa Local Health Authority, Italy.

Methods

We collected and analysed the infectious disease notifications made in two different three-years periods, 2017-2019 and 2020-2022 in Siracusa Local Health Authority, Italy. Descriptive statistics were used to find the percentages and the 95% confidence interval (CI). Exact "F-tests" was performed to compare the mean values between the studied periods to evaluate the hypothesis that the number of reported cases would not differ significantly between the two periods. Significance was assessed at the p < 0.05 level.

Results

The total number of notifications significantly decreased by 69.3% in the pandemic period compared to the pre-pandemic one, with the highest reduction of air-borne transmission diseases (-86.5%), followed by food-borne diseases (-68.2%) and sexually transmitted diseases (-39.3%). Conversely, an increase in number of notifications was found only for legionellosis.

Conclusions

The COVID-19 pandemic had the potential to influence communicable disease reporting at multiple points. While the effects could vary considerably, the results would be expected to reduce the number and the detection of notifiable cases. Included would be changes in exposures, diagnostic testing, reporting to public health agencies, and public health investigations.

Cause-Specific Excess Mortality During the COVID-19 Pandemic (2020-2021) in 12 Countries of the C-MOR Consortium

BACKGROUND

This study investigated cause-specific mortality rates in 12 countries during the COVID-19 pandemic in 2020 and 2021.

METHODS

We collected weekly cause-specific mortality data from respiratory disease, pneumonia, cardiovascular disease (CVD) and cancer from national vital statistic databases. We calculated excess mortality for respiratory disease (excluding COVID-19 codes), pneumonia, and CVD in 2020 and 2021 by comparing observed weekly against expected mortality based on historical data (2015-2019), accounting for seasonal trends. We used multilevel regression models to investigate the association between country-level pandemic-related variables and cause-specific mortality.

RESULTS

Significant reductions in cumulative mortality from respiratory disease and pneumonia were observed in 2020 and/or 2021, except for Georgia, Northern Ireland, Kazakhstan, and Ukraine, which exhibited excess mortality for one or both causes. Australia, Austria, Cyprus, Georgia, and Northern Ireland experienced excess cumulative CVD mortality in 2020 and/or 2021. Australia, Austria, Brazil, Cyprus, Georgia, Northern Ireland, Scotland and Slovenia, experienced increased crude cumulative cancer mortality during 2020 and/or 2021 compared to previous years. Among pandemic-related variables, reported COVID-19 incidence was negatively associated with increased cancer mortality, excess respiratory, (2020) and pneumonia (2021) mortality, and positively associated with respiratory and CVD mortality (2021). Stringency of control measures were negatively associated with excess respiratory disease, CVD, and increased cancer mortality (2021).

CONCLUSIONS

This study provides evidence of substantial excess mortality from CVD, and notable reductions in respiratory disease and pneumonia in both years across most countries investigated. Our study also highlights the beneficial impact of stringent control measures in mitigating excess mortality from most causes in 2021.

The Changing Landscape of Respiratory Viruses Contributing to Hospitalizations in Quebec, Canada: Results From an Active Hospital-Based Surveillance Study

BACKGROUND

A comprehensive description of the combined effect of SARS-CoV-2 and respiratory viruses other than SARS-CoV-2 (ORVs) on acute respiratory infection (ARI) hospitalizations is lacking.

OBJECTIVE

This study aimed to compare the viral etiology of ARI hospitalizations before the pandemic (8 prepandemic influenza seasons, 2012-13 to 2019-20) and during 3 pandemic years (periods of increased SARS-CoV-2 and ORV circulation in 2020-21, 2021-22, and 2022-23) from an active hospital-based surveillance network in Quebec, Canada.

METHODS

We compared the detection of ORVs and SARS-CoV-2 during 3 pandemic years to that in 8 prepandemic influenza seasons among patients hospitalized with ARI who were tested systematically by the same multiplex polymerase chain reaction (PCR) assay during periods of intense respiratory virus (RV) circulation. The proportions of infections between prepandemic and pandemic years were compared by using appropriate statistical tests.

RESULTS

During prepandemic influenza seasons, overall RV detection was 92.7% (1384/1493) (respiratory syncytial virus [RSV]: 721/1493, 48.3%; coinfections: 456/1493, 30.5%) in children (<18 years) and 62.8% (2723/4339) (influenza: 1742/4339, 40.1%; coinfections: 264/4339, 6.1%) in adults. Overall RV detection in children was lower during pandemic years but increased from 58.6% (17/29) in 2020-21 (all ORVs; coinfections: 7/29, 24.1%) to 90.3% (308/341) in 2021-22 (ORVs: 278/341, 82%; SARS-CoV-2: 30/341, 8.8%; coinfections: 110/341, 32.3%) and 88.9% (361/406) in 2022-23 (ORVs: 339/406, 84%; SARS-CoV-2: 22/406, 5.4%; coinfections: 128/406, 31.5%). In adults, overall RV detection was also lower during pandemic years but increased from 43.7% (333/762) in 2020-21 (ORVs: 26/762, 3.4%; SARS-CoV-2: 307/762, 40.3%; coinfections: 7/762, 0.9%) to 57.8% (731/1265) in 2021-22 (ORVs: 179/1265, 14.2%; SARS-CoV-2: 552/1265, 43.6%; coinfections: 42/1265, 3.3%) and 50.1% (746/1488) in 2022-23 (ORVs: 409/1488, 27.5%; SARS-CoV-2: 337/1488, 22.6%; coinfections: 36/1488, 2.4%). No influenza or RSV was detected in 2020-21; however, their detection increased in the 2 subsequent years but did not reach prepandemic levels. Compared to the prepandemic period, the peaks of RSV hospitalization shifted in 2021-22 (16 weeks earlier) and 2022-23 (15 weeks earlier). Moreover, the peaks of influenza hospitalization shifted in 2021-22 (17 weeks later) and 2022-23 (4 weeks earlier). Age distribution was different compared to the prepandemic period, especially during the first pandemic year.

CONCLUSIONS

Significant shifts in viral etiology, seasonality, and age distribution of ARI hospitalizations occurred during the 3 pandemic years. Changes in age distribution observed in our study may reflect modifications in the landscape of circulating RVs and their contribution to ARI hospitalizations. During the pandemic period, SARS-CoV-2 had a low contribution to pediatric ARI hospitalizations, while it was the main contributor to adult ARI hospitalizations during the first 2 seasons and dropped below ORVs during the third pandemic season. Evolving RVs epidemiology underscores the need for increased scrutiny of ARI hospitalization etiology to inform tailored public health recommendations.

SARS-CoV-2 pandemic non-pharmacologic interventions temporally associated with reduced pediatric infections due to Mycoplasma pneumoniae and co-infecting respiratory viruses in Arkansas

Non-pharmacologic interventions (NPIs), such as universal masking, implemented during the SARS-CoV-2 pandemic have reduced respiratory infections among children. This study evaluated the impact of NPIs on Mycoplasma pneumoniae infections in children, analyzing data from two hospitals in Arkansas and examining age-related differences and co-infections with other respiratory viruses. The study was approved by the Institutional Review Board and included patients (≤18 years) with upper respiratory tract symptoms. Data generated from the FilmArray Respiratory Panel were divided into pre-NPI, NPI, and post-NPI periods for analysis. Overall test positivity rate and positivity rate interval changes were evaluated. Statistical differences were determined by Chi-square (χ2 independence) analysis. A total of 100,077 tests were performed, with a statistical increase in testing volume during the NPI and post-NPI periods. The number of positive M. pneumoniae tests decreased by 77% (77 to 18) during the NPI period, then increased by 50% (18 to 27) during the post-NPI period. Preschool and elementary school age groups had the highest number of positive tests during the study at 59 (48%) and 40 (33%), respectively. Reduced M. pneumoniae infections were consistent across age groups. Co-infections with other respiratory viruses, particularly human rhinovirus/enterovirus, were observed at much lower levels. Pediatric M. pneumoniae infections in Arkansas were temporally associated with implementation and discontinuation of NPIs. Specific viral co-infections still occurred, albeit at lower levels during the SARS-CoV-2 pandemic. Because of the slower growth of this bacterium, we expect M. pneumoniae infections to return to pre-pandemic levels within approximately 2 years.

IMPORTANCE

Non-pharmacologic interventions (NPIs) effectively curtailed the spread of SARS-CoV-2 and, fortuitously, many other aerosol-transmitted respiratory pathogens. This study included the largest data set of symptomatic, pediatric patients from within the United States spanning a period from November 2017 through December 2023, and encompassed individuals residing in both rural and urban settings. We observed a strong correlation between the implementation and cessation of NPIs with the rate of respiratory infections due to Mycoplasma pneumoniae and viral co-infections. These infections are returning to baseline levels approximately 2 years following NPI cessation. This observation was not unexpected since the replication time for viruses is exponentially faster than that of bacteria. The resurgence of M. pneumoniae and likely other atypical bacterial pathogens is currently in process. Healthcare providers should strongly consider these pathogens in individuals presenting with respiratory tract illnesses.

Investigation of air dispersal during a rhinovirus outbreak in a pediatric intensive care unit

BACKGROUND

While airborne transmission of rhinovirus is recognized in indoor settings, its role in hospital transmission remains unclear.

METHODS

We investigated an outbreak of rhinovirus in a pediatric intensive care unit (PICU) to assess air dispersal. We collected clinical, environmental, and air samples, and staff's surgical masks for viral load and phylogenetic analysis. Hand hygiene compliance and the number of air changes per hour in the PICU were measured. A case-control analysis was performed to identify nosocomial rhinovirus risk factors.

RESULTS

Between March 31, 2023, and April 2, 2023, three patients acquired rhinovirus in a cubicle (air changes per hour: 14) of 12-bed PICU. A portable air-cleaning unit was placed promptly. Air samples (72,000 L in 6 hours) from the cohort area, and outer surfaces of staff's masks (n = 8), were rhinovirus RNA-negative. Hand hygiene compliance showed no significant differences (31/34, 91.2% vs 33/37, 89.2%, P = 1) before and during outbreak. Only 1 environmental sample (3.8%) was positive (1.86 × 103 copies/mL). Case-control and next-generation sequencing analysis implicated an infected staff member as the source.

CONCLUSIONS

Our findings suggest that air dispersal of rhinovirus was not documented in the well-ventilated PICU during the outbreak. Further research is needed to better understand the dynamics of rhinovirus transmission in health care settings.

The impact of non-pharmaceutical interventions on community non-SARS-CoV-2 respiratory infections in preschool children

BACKGROUND

Effects of non-pharmaceutical interventions during the pandemic were mainly studied for severe outcomes. Among children, most of the burden of respiratory infections is related to infections which are not medically attended. The perspective on infections in the community setting is necessary to understand the effects of the pandemic on non-pharmaceutical interventions.

METHODS

In the unique prospective LoewenKIDS cohort study, we compared the true monthly incidence of self-reported acute respiratory infections (ARI) in about 350 participants (aged 3-4 years old) between October 2019 to March 2020 (pre-pandemic period) and October 2020 to March 2021 (pandemic period). Parents reported children's symptoms using a diary. Parents were asked to take a nasal swab of their child during all respiratory symptoms. We analysed 718 swabs using Multiplex PCR for 25 common respiratory viruses and bacteria.

RESULTS

During the pre-pandemic period, on average 44.6% (95% CI: 39.5-49.8%) of children acquired at least one ARI per month compared to 19.9% (95% CI: 11.1-28.7%) during the pandemic period (Incidence Rate Ratio = 0.47; 95% CI: 0.41-0.54). The detection of influenza virus decreased absolute by 96%, respiratory syncytial virus by 65%, metapneumovirus by 95%, parainfluenza virus by 100%, human enterovirus by 96% and human bocavirus by 70% when comparing the pre-pandemic to the pandemic period. However, rhinoviruses were nearly unaffected by NPI. Co-detection (detection of more than one virus in a single symptomatic swab) was common in the pre-pandemic period (222 of 390 samples with viral detection; 56.9%) and substantially less common during the pandemic period (46 of 216 samples; 21.3%).

CONCLUSION

Non-pharmaceutical interventions strongly reduced the incidence of all respiratory infections in preschool children but did not affect rhinovirus.

Use of Sentinel Surveillance Platforms for Monitoring SARS-CoV-2 Activity: Evidence From Analysis of Kenya Influenza Sentinel Surveillance Data

BACKGROUND

Little is known about the cocirculation of influenza and SARS-CoV-2 viruses during the COVID-19 pandemic and the use of respiratory disease sentinel surveillance platforms for monitoring SARS-CoV-2 activity in sub-Saharan Africa.

OBJECTIVE

We aimed to describe influenza and SARS-CoV-2 cocirculation in Kenya and how the SARS-CoV-2 data from influenza sentinel surveillance correlated with that of universal national surveillance.

METHODS

From April 2020 to March 2022, we enrolled 7349 patients with severe acute respiratory illness or influenza-like illness at 8 sentinel influenza surveillance sites in Kenya and collected demographic, clinical, underlying medical condition, vaccination, and exposure information, as well as respiratory specimens, from them. Respiratory specimens were tested for influenza and SARS-CoV-2 by real-time reverse transcription polymerase chain reaction. The universal national-level SARS-CoV-2 data were also obtained from the Kenya Ministry of Health. The universal national-level SARS-CoV-2 data were collected from all health facilities nationally, border entry points, and contact tracing in Kenya. Epidemic curves and Pearson r were used to describe the correlation between SARS-CoV-2 positivity in data from the 8 influenza sentinel sites in Kenya and that of the universal national SARS-CoV-2 surveillance data. A logistic regression model was used to assess the association between influenza and SARS-CoV-2 coinfection with severe clinical illness. We defined severe clinical illness as any of oxygen saturation <90%, in-hospital death, admission to intensive care unit or high dependence unit, mechanical ventilation, or a report of any danger sign (ie, inability to drink or eat, severe vomiting, grunting, stridor, or unconsciousness in children younger than 5 years) among patients with severe acute respiratory illness.

RESULTS

Of the 7349 patients from the influenza sentinel surveillance sites, 76.3% (n=5606) were younger than 5 years. We detected any influenza (A or B) in 8.7% (629/7224), SARS-CoV-2 in 10.7% (768/7199), and coinfection in 0.9% (63/7165) of samples tested. Although the number of samples tested for SARS-CoV-2 from the sentinel surveillance was only 0.2% (60 per week vs 36,000 per week) of the number tested in the universal national surveillance, SARS-CoV-2 positivity in the sentinel surveillance data significantly correlated with that of the universal national surveillance (Pearson r=0.58; P<.001). The adjusted odds ratios (aOR) of clinical severe illness among participants with coinfection were similar to those of patients with influenza only (aOR 0.91, 95% CI 0.47-1.79) and SARS-CoV-2 only (aOR 0.92, 95% CI 0.47-1.82).

CONCLUSIONS

Influenza substantially cocirculated with SARS-CoV-2 in Kenya. We found a significant correlation of SARS-CoV-2 positivity in the data from 8 influenza sentinel surveillance sites with that of the universal national SARS-CoV-2 surveillance data. Our findings indicate that the influenza sentinel surveillance system can be used as a sustainable platform for monitoring respiratory pathogens of pandemic potential or public health importance.

The impact of the COVID-19 pandemic on the circulation, seasonal distribution, and research of other respiratory pathogens in Turkey

INTRODUCTION

Respiratory infections are one of the world's most common infectious diseases. Following the species, numbers, and seasonal distribution of acute respiratory agents is important for the protection of public health. Our study aimed to determine the effect of the COVID-19 pandemic on the circulation and seasonal distribution of non-SARS-CoV-2 respiratory tract agents and research on non-SARS-CoV-2 agents.

METHODS

The results of the Multiplex PCR respiratory panel of 3702 nasopharyngeal swab samples sent between January 2018 and December 2021 were evaluated retrospectively. Scientific articles on acute respiratory infections between 2010 and 2021 from Turkey were analyzed in Scopus for bibliometric analysis.

RESULTS

1.382 pathogens were detected. During the pandemic, the number of non-SARS-CoV-2 pathogens was found to be statistically significantly lower than before the pandemic. It was determined that while the most frequent agent before the pandemic was the Adenovirus, the most frequent agent was the RSV-A during the pandemic. Our network analysis of keywords indicated that academic interest in 2020-21 was directed toward COVID-19, which coincides with the pandemic period.

CONCLUSIONS

Our study determined the fact that the incidence, species, and seasonal distribution of non-SARS-COV-2 respiratory agents changed after the onset of the pandemic. Increasing the identification and following-up of these pathogens in health organizations and also presenting these data to literature and sharing with academics is important. We are of the opinion that the results of our study shall shed light on the epidemiology of changing respiratory infections and the prevention and following-up of future health problems.

Influenza A (H1N1) Virus Outbreak in the Districts of Chhattisgarh: A Cross-Sectional Study

Background The H1N1 flu is a subtype of the influenza A virus, also known as the swine flu. An entirely new strain of the H1N1 virus started sickening people in the 2009-2010 flu season. It was a novel influenza virus combination that can infect humans, pigs, and birds. It was frequently referred to as the "swine flu." The virus may be able to spread for a little while longer in children and individuals with compromised immune systems. Objective The objective is to investigate the outbreaks of H1N1 among young adults in the Bastar District of Chhattisgarh. Methods Collection of the blood samples of 342 individuals between December 2015 and November 2017 was done. Thirty-one cases of Influenza A (H1N1) PDM09 virus infection were identified and confirmed. The molecular relationship between viruses is identified by the real-time polymerase chain reaction (RT-PCR) method. Result The majority of samples (n=13) were sourced from Raipur Medical College, followed by contributions from Durg District Hospital (n=5), Raigarh Medical College (n=4), Rajnandgaon District Hospital (n=3), Jagdalpur Medical College (n=2), Bilaspur Medical College (n=2), and smaller contributions from Dhamtari District Hospital and Gariyabandh Primary Health Care. Among these, 31 samples tested positive for Influenza A (H1N1) PDM 2009 virus, with a slightly higher prevalence among 19 female patients. Age-wise distribution revealed higher proportions of positive cases in the age groups of 0-10 years, 31-40 years, and 21-30 years. In the molecular analysis, 154 samples showed no target amplification, while 125 samples exhibited amplification of only Influenza A without subtype (H1) amplification. Remarkably, 31 patients who tested positive for Influenza A (H1N1) died from the virus; most of the deaths were in children under five and middle-aged adults. Conclusion The detection of Influenza A (H1N1) PDM 2009 virus, especially among females, indicates its persistent circulation. Positive cases were prevalent among younger and middle-aged individuals. Molecular analysis showed subtype variations, with significant fatalities observed in children under five and middle-aged adults, emphasizing the severity of the virus across different age groups. It is advised that in order to keep Indian influenza surveillance up to date and robust, more epidemiological data should be gathered, along with information on risk factors like immunization status, hospitalization, and mortality rates should be estimated, and influenza case subtyping should be improved.

Impact of the COVID-19 related border restrictions on influenza and other common respiratory viral infections in New Zealand

BACKGROUND

New Zealand's (NZ) complete absence of community transmission of influenza and respiratory syncytial virus (RSV) after May 2020, likely due to COVID-19 elimination measures, provided a rare opportunity to assess the impact of border restrictions on common respiratory viral infections over the ensuing 2 years.

METHODS

We collected the data from multiple surveillance systems, including hospital-based severe acute respiratory infection surveillance, SHIVERS-II, -III and -IV community cohorts for acute respiratory infection (ARI) surveillance, HealthStat sentinel general practice (GP) based influenza-like illness surveillance and SHIVERS-V sentinel GP-based ARI surveillance, SHIVERS-V traveller ARI surveillance and laboratory-based surveillance. We described the data on influenza, RSV and other respiratory viral infections in NZ before, during and after various stages of the COVID related border restrictions.

RESULTS

We observed that border closure to most people, and mandatory government-managed isolation and quarantine on arrival for those allowed to enter, appeared to be effective in keeping influenza and RSV infections out of the NZ community. Border restrictions did not affect community transmission of other respiratory viruses such as rhinovirus and parainfluenza virus type-1. Partial border relaxations through quarantine-free travel with Australia and other countries were quickly followed by importation of RSV in 2021 and influenza in 2022.

CONCLUSION

Our findings inform future pandemic preparedness and strategies to model and manage the impact of influenza and other respiratory viral threats.

Prevalence of Endemic Respiratory Viruses During the COVID-19 Pandemic in Urban and Rural Malawi

Background

We investigated endemic respiratory virus circulation patterns in Malawi, where no lockdown was imposed, during the COVID-19 pandemic.

Methods

Within a prospective household cohort in urban and rural Malawi, adult participants provided upper respiratory tract (URT) samples at 4 time points between February 2021 and April 2022. Polymerase chain reaction (PCR) was performed for SARS-CoV-2, influenza, and other endemic respiratory viruses.

Results

1626 URT samples from 945 participants in 542 households were included. Overall, 7.6% (n = 123) samples were PCR- positive for >1 respiratory virus; SARS-CoV-2 (4.4%) and rhinovirus (2.0%) were most common. No influenza A virus was detected. Influenza B and respiratory syncytial virus (RSV) were rare. Higher virus positivity were detected in the rural setting and at earlier time points. Coinfections were infrequent.

Conclusions

Endemic respiratory viruses circulated in the community in Malawi during the pandemic, though influenza and RSV were rarely detected. Distinct differences in virus positivity and demographics were observed between urban and rural cohorts.

Influence of COVID-19 over seasonal influenza activity in southern India

Basic epidemiological data is urgently needed in order to ascertain the changes brought about by COVID-19 pandemic, and help researchers, clinicians, and policy makers in addressing these issues. Data on influenza positivity from 2009 to 2019 was collected from Regional Influenza laboratory, JIPMER. Being COVID testing centre we tested samples (2020-2023) from Tamilnadu and Pondicherry. All SARI samples which were negative for COVID-19 were subjected to Influenza testing as regular surveillance activity was suspended. On comparison we found significant reduction in detection rates of influenza A H1N1, H3N2 and influenza B (p value = <0.01).

Vaccination against influenza viruses reduces infection, not hospitalization or death, from respiratory COVID-19: A systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has brought a huge burden in terms of human lives. Strict social distance and influenza vaccination have been recommended to avoid co-infections between influenza viruses and SARS-CoV-2. Scattered reports suggested a protective effect of influenza vaccine on COVID-19 development and severity. We analyzed 51 studies on the capacity of influenza vaccination to affect infection with SARS-CoV-2, hospitalization, admission to Intensive Care Units (ICU), and mortality. All subjects taken into consideration did not receive any anti-SARS-CoV-2 vaccine, although their status with respect to previous infections with SARS-CoV-2 is not known. Comparison between vaccinated and not-vaccinated subjects for each of the four endpoints was expressed as odds ratio (OR), with 95% confidence intervals (CIs); all analyses were performed by DerSimonian and Laird model, and Hartung-Knapp model when studies were less than 10. In a total of 61 029 936 subjects from 33 studies, influenza vaccination reduced frequency of SARS-CoV-2 infection [OR plus 95% CI = 0.70 (0.65-0.77)]. The effect was significant in all studies together, in health care workers and in the general population; distance from influenza vaccination and the type of vaccine were also of importance. In 98 174 subjects from 11 studies, frequency of ICU admission was reduced with influenza vaccination [OR (95% CI) = 0.71 (0.54-0.94)]; the effect was significant in all studies together, in pregnant women and in hospitalized subjects. In contrast, in 4 737 328 subjects from 14 studies hospitalization was not modified [OR (95% CI) = 1.05 (0.82-1.35)], and in 4 139 660 subjects from 19 studies, mortality was not modified [OR (95% CI) = 0.76 (0.26-2.20)]. Our study emphasizes the importance of influenza vaccination in the protection against SARS-CoV-2 infection.

The impact of non-pharmacologic interventions on respiratory syncytial virus hospitalization during the COVID-19 pandemic: A retrospective study from Saudi Arabia

BACKGROUND

Acute respiratory tract infections (ARTIs) are frequently observed in infants and young children. The dynamics and transmission of ARTIs have been significantly impacted by the global COVID-19 pandemic. This study investigates the change in admission rates of Respiratory Syncytial virus (RSV) in a hospital in Saudi Arabia.

METHODS

The study included hospitalized pediatric patients who underwent RSV testing in three periods: pre-pandemic (2019), during the pandemic (2020-2021), and the immediate post-pandemic (2022). RSV testing was conducted using either PCR or antigen tests.

RESULTS

Between January 2019 to December 2022, out of 927 tested patients, 173 (18.7%) were positive for RSV. The yearly positivity rates were as follows: 42 (35.6%) of 118, 24 (33.3%) of 72, 15 (18.5%) of 81, and 92 (14%) of 656, yearly from 2019 to 2022, respectively (P < 0.00001). Among all cases, 150 (16.2%) required hospitalization, including 94 (62.7%) males and 56 (37.3%) females. The admission rate to the intensive care unit (ICU) was 25 (16.7%), and mechanical ventilation was required for 10 (6.6%) patients. The overall case fatality rate was 0.7%. A Binary logistic regression analysis showed upper respiratory tract symptoms were more common in patients admitted in 2019 compared to 2022 (odd ratio:20.9, 95% CI: 4.2-104.1, P value < 0.0001).

CONCLUSION

The study showed that there were differences in RSV infection before and after COVID-19. Understanding how COVID-19 mitigation measures affect RSV transmission can aid in the development of effective prevention and control strategies.

Effects of Coronavirus Disease 2019 on Prevalence of Acute Respiratory Viruses: Changes during the Pandemic

Introduction

The coronavirus disease 2019 (COVID-19) pandemic may have influenced the prevalence and seasonality of acute respiratory viral infections. The aim of the study was to investigate the prevalence of all viruses causing acute viral respiratory infections before and after social distancing measures were lifted.

Methods

Cross-sectional study where outpatients and inpatients at Kyunghee University Hospital were examined. From January 2021 to December 2022, respiratory samples were analyzed using multiplex reverse transcriptase real-time polymerase chain reaction.

Results

Of 3953 samples obtained, 412 (10.42%) were positive for acute respiratory viral infection, and 502 viruses were detected. The number of viral infections increased from 184 in 2021 to 318 in 2022. Human metapneumovirus was detected from August to November 2022. Human bocavirus (HBoV) was frequently detected from April to June 2021; however, in 2022, HBoV was frequently detected from July to October. Human parainfluenza virus 3 was rarely detected after its initial frequent detection from October to December 2021 but was continuously observed after frequent detection in September 2022. Co-infection occurred in 78 (18.9%) cases. The most common combination of simultaneous infections was human rhinovirus-HBoV (n = 30, 38.5%).

Conclusions

During the COVID-19 pandemic, the incidence of acute respiratory viral infection decreased significantly but increased in 2022 when measures were lifted. The prevalence and seasonality of respiratory viral infections have changed since the pandemic. Our findings contribute to the prediction of an effective response to changes in the prevalence of respiratory viruses.

Outpatient antibiotic prescribing during the first two years of the COVID-19 pandemic: A nationwide register-based time series analysis

The COVID-19 pandemic has imposed an enormous burden on health care systems around the world. Simultaneously, many countries have reported a decrease in the incidence of other infectious diseases, such as acute respiratory infections, leading to a decline in outpatient antibiotic use. The aim of this study is to assess the impact of the COVID-19 pandemic on outpatient antibiotic prescribing in Finland during the first 2 years of the pandemic. We used nationwide register data, applied descriptive methods, and conducted an interrupted time series analysis (ITSA) using ARIMA modelling. Results from the ARIMA modelling showed that at the baseline, before the pandemic, the level of monthly number of antibiotic prescriptions was 248,560 (95% CI: 224,261 to 272,856; p<0.001) and there was a decreasing trend of 1,202 in monthly number of prescriptions (95% CI: -2,107 to -262; p<0.01). After the COVID-19 pandemic began, there was a statistically significant decline of 48,470 (95% CI: -76,404 to -20,535, p<0.001) prescriptions (-19.5% from the baseline level). The greatest decrease in antibiotic prescribing was observed among children aged 0-17 years. While antibiotic prescribing declined in all antibiotic groups associated with respiratory tract infections, the decrease from 2019 to 2020 was the largest with azithromycin (52.6%), amoxicillin (44.8%), and doxycycline (43.8%). Future studies should continue exploring antibiotic prescribing trends during the COVID-19 pandemic and beyond.

Urgent Hospitalizations Related to Viral Respiratory Disease in Children during Autumn and Winter Seasons 2022/2023

AIM

The loosening of social distancing measures over the past two years has led to a resurgence of seasonal epidemics associated with respiratory viral infections in children. We aim to describe the impact of such infections through urgent hospitalizations in a pediatric emergency department.

METHODS

We performed a retrospective review of medical records of all children and adolescents with a positive nasal swab admitted at the children's hospital IRCCS Burlo Garofolo of Trieste, in Italy, from September 2021 to March 2022, and September 2022 to March 2023.

RESULTS

Respiratory Syncytial Virus and Influenza viruses accounted for up to 55% of hospitalizations for respiratory infections during the study periods. During the last season, the number of hospitalizations related to the Influenza virus was five times higher than those related to SARS-CoV-2 (25% vs. 5%). Respiratory Syncytial Virus was associated with a greater need for respiratory support, mostly HFNC (High Flow Nasal Cannula).

CONCLUSIONS

Respiratory Syncytial Virus and Influenza virus had a more significant impact on urgent hospitalizations during the past wintery seasons than SARS-CoV-2.

Resurgence of human metapneumovirus infection and influenza after three seasons of inactivity in the post-COVID-19 era in Hokkaido, Japan, 2022-2023

Following the coronavirus disease 2019 (COVID-19) outbreak in February 2020, incidences of various infectious diseases decreased notably in Hokkaido Prefecture, Japan. However, Japan began gradually easing COVID-19 infection control measures in 2022. Here, we conducted a survey of children hospitalized with human metapneumovirus (hMPV), influenza A and B, and respiratory syncytial virus infections in 18 hospitals across Hokkaido Prefecture, Japan, spanning from July 2019 to June 2023. From March 2020 to June 2022 (28 months), only 13 patients were hospitalized with hMPV, and two patients had influenza A. However, in October to November 2022, there was a re-emergence of hMPV infections, with a maximum of 27 hospitalizations per week. From July 2022 to June 2023 (12 months), the number of hMPV-related hospitalizations dramatically increased to 317 patients, with the majority aged 3-6 years (38.2%, [121/317]). Influenza A also showed an increase from December 2022, with a peak of 13 hospitalizations per week in March 2023, considerably fewer than the pre-COVID-19 outbreak in December 2019, when rates reached 45 hospitalizations per week. These findings suggest the possibility of observing more resurgences in infectious diseases in Japan after 2023 if infection control measures continue to be relaxed. Caution is needed in managing potential outbreaks.

The effect of quercetin supplementation on clinical outcomes in COVID-19 patients: A systematic review and meta-analysis

Coronavirus disease (COVID-19) affects both the respiratory system and the body as a whole. Natural molecules, such as flavonoid quercetin, as potential treatment methods to help patients combat COVID-19. The aim of this systematic review and meta-analysis is to give a comprehensive overview of the impact of quercetin supplementation on inflammatory factors, hospital admission, and mortality of patients with COVID-19. The search has been conducted on PubMed, Scopus, Web of Science, EMBASE, and the Cochrane Library using relevant keywords until August 25, 2023. We included randomized controlled trials (RCTs) comparing COVID-19 patients who received quercetin supplementation versus controls. We included five studies summarizing the evidence in 544 patients. Meta-analysis showed that quercetin administration significantly reduced LDH activity (standard mean difference (SMD): -0.42, 95% CI: -0.82, -0.02, I 2 = 48.86%), decreased the risk of hospital admission by 70% (RR: 0.30, 95% CI: 0.14, 0.62, I 2 = 00.00%), ICU admission by 73% (RR: 0.27, 95% CI: 0.09, 0.78, I 2 = 20.66%), and mortality by 82% (RR: 0.18, 95% CI: 0.03, 0.98, I 2 = 00.00%). No significant changes in CRP, D-dimmer, and ferritin were found between groups. Quercetin was found to significantly reduce LDH levels and decrease the risk of hospital and ICU admission and mortality in patients with COVID-19 infection.