Influence of school closure on the incidence of viral respiratory diseases among children and on health care utilization

Evaluating the dynamic interplay of social distancing policies regarding airborne pathogens through a temporal interaction-driven model that uses real-world and synthetic data

OBJECTIVE

The recent SARS-CoV-2 pandemic has exhibited diverse patterns of spread across countries and communities, emphasizing the need to consider the underlying population dynamics in modeling its progression and the importance of evaluating the effectiveness of non-pharmaceutical intervention strategies in combating viral transmission within human communities. Such an understanding requires accurate modeling of the interplay between the community dynamics and the disease propagation dynamics within the community.

METHODS

We build on an interaction-driven model of an airborne disease over contact networks that we have defined. Using the model, we evaluate the effectiveness of temporal, spatial, and spatiotemporal social distancing policies. Temporal social distancing involves a pure dilation of the timeline while preserving individual activity potential and thus prolonging the period of interaction; spatial distancing corresponds to social distancing pods; and spatiotemporal distancing pertains to the situation in which fixed subgroups of the overall group meet at alternate times. We evaluate these social distancing policies over real-world interactions' data and over history-preserving synthetic temporal random networks. Furthermore, we evaluate the policies for the disease's with different number of initial patients, corresponding to either the phase in the progression of the infection through a community or the number of patients infected together at the initial infection event. We expand our model to consider the exposure to viral load, which we correlate with the meetings' duration.

RESULTS

Our results demonstrate the superiority of decreasing social interactions (i.e., time dilation) within the community over partial isolation strategies, such as the spatial distancing pods and the spatiotemporal distancing strategy. In addition, we found that slow-spreading pathogens (i.e., pathogens that require a longer exposure to infect) spread roughly at the same rate as fast-spreading ones in highly active communities. This result is surprising since the pathogens may follow different paths. However, we demonstrate that the dilation of the timeline considerably slows the spread of the slower pathogens.

CONCLUSIONS

Our results demonstrate that the temporal dynamics of a community have a more significant effect on the spread of the disease than the characteristics of the spreading processes.

The Impact of COVID-19 Restrictions on Hospital Admissions of Common Head and Neck Infections

INTRODUCTION

Following the emergence of COVID-19, multiple preventative measures were implemented to limit the spread of the disease. This study aims to elucidate the impact of COVID-19 restrictions on hospital admissions of otolaryngology-related infections.

MATERIALS AND METHODS

A retrospective chart review was conducted to capture all admissions for otolaryngology-related infections in the 2 years pre- and post-COVID-19 at the Health Sciences Centre in Winnipeg, Manitoba. These infections included croup, tracheitis, neck abscess, peritonsillar abscess, otitis media, mastoiditis, sinus infection, orbital infection, pharyngotonsillitis, retro/parapharyngeal abscess, and acute epiglottitis. Demographic information and admission details were collected and analyzed to compare pre- and post-COVID-19 admissions. Further analysis was conducted to compare hospital admissions of patients from rural/remote regions.

RESULTS

Between March 2018 and March 2022, 253 pediatric patients and 197 adults were admitted for otolaryngology-related infections. Total pediatric admissions decreased post-COVID-19 (154 pre-COVID-19, 99 post-COVID-19; p < 0.001) whereas adult admissions remained stable (107 pre-COVID-19, 90 post-COVID-19; p = 0.25). No significant difference in mean patient age, admission duration, surgical rates or in the proportion of admissions from patients from rural/remote regions was observed in the pediatric or adult cohort when comparing pre-COVID-19 data to post-COVID-19 data. Diagnosis-specific changes in admissions were observed in pediatric croup (40 pre-COVID-19, 15 post-COVID-19; p < 0.001) and in adult orbital infections (30 pre-COVID-19, six post-COVID-19; p < 0.001).

CONCLUSION

Following the implementation of COVID-19 restrictions, there was a decrease in admissions due to pediatric croup and adult orbital infections with an overall decrease in pediatric Otolaryngology-infection related admissions.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

A beta-Poisson model for infectious disease transmission

Outbreaks of emerging and zoonotic infections represent a substantial threat to human health and well-being. These outbreaks tend to be characterised by highly stochastic transmission dynamics with intense variation in transmission potential between cases. The negative binomial distribution is commonly used as a model for transmission in the early stages of an epidemic as it has a natural interpretation as the convolution of a Poisson contact process and a gamma-distributed infectivity. In this study we expand upon the negative binomial model by introducing a beta-Poisson mixture model in which infectious individuals make contacts at the points of a Poisson process and then transmit infection along these contacts with a beta-distributed probability. We show that the negative binomial distribution is a limit case of this model, as is the zero-inflated Poisson distribution obtained by combining a Poisson-distributed contact process with an additional failure probability. We assess the beta-Poisson model's applicability by fitting it to secondary case distributions (the distribution of the number of subsequent cases generated by a single case) estimated from outbreaks covering a range of pathogens and geographical settings. We find that while the beta-Poisson mixture can achieve a closer to fit to data than the negative binomial distribution, it is consistently outperformed by the negative binomial in terms of Akaike Information Criterion, making it a suboptimal choice on parsimonious grounds. The beta-Poisson performs similarly to the negative binomial model in its ability to capture features of the secondary case distribution such as overdispersion, prevalence of superspreaders, and the probability of a case generating zero subsequent cases. Despite this possible shortcoming, the beta-Poisson distribution may still be of interest in the context of intervention modelling since its structure allows for the simulation of measures which change contact structures while leaving individual-level infectivity unchanged, and vice-versa.

Prolonged School Closure and Pediatric Respiratory Hospitalization: The Silver Lining of the COVID-19 Pandemic

Objective. This is a single-center retrospective cohort study that aimed to quantitatively assess the association between prolonged school closure (>2 weeks) and pediatric respiratory hospitalization during the COVID-19 pandemic. Methods. Subjects included 1243 patients presenting to Children's Hospital of Michigan during the winters of 2019, 2020, and 2021. The primary outcome measures were total respiratory hospitalizations and respiratory diagnoses. Results. Data was analyzed using a 2-sample z-test for proportions. We found that pediatric patients in the setting of prolonged school closure had significantly fewer hospitalizations in 2020 compared to 2019 (9% vs 47%; P < .001) and 2021 (9% vs 45%; P < .001). There were decreases in bronchiolitis, asthma/reactive airway disease (RAD), and pneumonia hospitalizations compared to 2019 and 2021. Conclusions. Our study showed that during prolonged school closure, there was a significant decrease in pediatric respiratory hospitalization. As such, it should be considered when creating a pandemic response strategy.

The impact of anthropogenic climate change on pediatric viral diseases

The adverse effects of climate change on human health are unfolding in real time. Environmental fragmentation is amplifying spillover of viruses from wildlife to humans. Increasing temperatures are expanding mosquito and tick habitats, introducing vector-borne viruses into immunologically susceptible populations. More frequent flooding is spreading water-borne viral pathogens, while prolonged droughts reduce regional capacity to prevent and respond to disease outbreaks with adequate water, sanitation, and hygiene resources. Worsening air quality and altered transmission seasons due to an increasingly volatile climate may exacerbate the impacts of respiratory viruses. Furthermore, both extreme weather events and long-term climate variation are causing the destruction of health systems and large-scale migrations, reshaping health care delivery in the face of an evolving global burden of viral disease. Because of their immunological immaturity, differences in physiology (e.g., size), dependence on caregivers, and behavioral traits, children are particularly vulnerable to climate change. This investigation into the unique pediatric viral threats posed by an increasingly inhospitable world elucidates potential avenues of targeted programming and uncovers future research questions to effect equitable, actionable change. IMPACT: A review of the effects of climate change on viral threats to pediatric health, including zoonotic, vector-borne, water-borne, and respiratory viruses, as well as distal threats related to climate-induced migration and health systems. A unique focus on viruses offers a more in-depth look at the effect of climate change on vector competence, viral particle survival, co-morbidities, and host behavior. An examination of children as a particularly vulnerable population provokes programming tailored to their unique set of vulnerabilities and encourages reflection on equitable climate adaptation frameworks.

Does social distancing impact pediatric upper airway infections? An observational controlled study and a brief literature review

PURPOSE

SARS-CoV-2 pandemic has reduced social interaction even among children. The objective of the study was to assess the role of social distancing in the course of common pediatric upper airway recurrent diseases.

MATERIALS AND METHODS

Patients aged ≤14 years with at least one ENT-related clinical condition were retrospectively recruited. All patients had two outpatient evaluations in the same period (April - September): the control group had the first evaluation in 2018 and second in 2019, whereas the case group had the first evaluation in 2019 and second in 2020. Patients of each group were individually compared between their two visits and deemed improved/unchanged/worsened for each specific ENT condition. The percentage of children improved/unchanged/worsened were then collectively compared between the two groups for each condition.

RESULTS

Patients who experienced social distancing presented a significantly higher improvement rate than controls for recurrent acute otitis media episodes (35.1 % vs. 10.8 %; Fisher's exact test p = 0.033) and for tympanogram type (54.5 % vs. 11.1 %, Fisher's exact test p = 0.009).

CONCLUSIONS

The anti-contagion social restrictions decreased the prevalence of middle ear infections and effusion in children. Further studies on larger cohorts are required to better elucidate these findings.

A Retrospective Database Analysis of Before and After Social Distancing in Relation to Pediatric Infection Rate and Healthcare Services Usage During the Coronavirus Disease 2019 Pandemic

BACKGROUND

Social distancing policy was introduced in Israel in 2020 to reduce the spread of coronavirus disease 2019 (COVID-19). The aim of this study was to analyze the effect of social distancing on other infections in children, by comparing disease rate and healthcare utilization before and after social distancing.

METHODS

This was a before-and-after study. Within this retrospective database analysis of parallel periods in 2019 (periods 1 and 2) and 2020 (periods 3 [prelockdown period] and 4 [lockdown period]) we included all pediatric population registered in the electronic medical records of the Maccabi Healthcare Services, Israel, looking at the occurrence of non-COVID-19 infections, antibiotic purchasing, physician visits, ambulatory emergency care center visits, emergency department visits, and hospitalizations.

RESULTS

A total of 776 828 children were included from 2019, and 777 729 from 2020. We found a lower infection rate in 2020 versus 2019. We did not find a difference in infection rate between periods 1 and 2, while there was a significant difference between periods 3 and 4. We found a significant difference between periods 2 and 4, with a higher RR than for the comparison between periods 1 and 3. There was a modest decrease in ambulatory emergency care center visits in 2020, and lower increases in emergency department visits and hospital admissions. We found decreases in antibiotic purchasing between periods 1 and 3 and between periods 2 and 4, more pronounced in 2020 than in 2019.

CONCLUSIONS

Analysis of findings before and after social distancing and masking showed reduced prevalence of non-COVID-19 pediatric infections and reduced consumption of healthcare services and antibiotics related with the lockdown period.

Influence of epidemics and pandemics on paediatric ED use: a systematic review

OBJECTIVE

To assess the impact of epidemics and pandemics on the utilisation of paediatric emergency care services to provide health policy advice.

SETTING

Systematic review.

DESIGN

Searches were conducted of Medline, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Library for studies that reported on changes in paediatric emergency care utilisation during epidemics (as defined by the WHO).

PATIENTS

Children under 18 years.

INTERVENTIONS

National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies was used.

MAIN OUTCOME MEASURES

Changes in paediatric emergency care utilisation.

RESULTS

131 articles were included within this review, 80% of which assessed the impact of COVID-19. Studies analysing COVID-19, SARS, Middle East respiratory syndrome (MERS) and Ebola found a reduction in paediatric emergency department (PED) visits, whereas studies reporting on H1N1, chikungunya virus and Escherichia coli outbreaks found an increase in PED visits. For COVID-19, there was a reduction of 63.86% (95% CI 60.40% to 67.31%) with a range of -16.5% to -89.4%. Synthesis of results suggests that the fear of the epidemic disease, from either contracting it or its potential adverse clinical outcomes, resulted in reductions and increases in PED utilisation, respectively.

CONCLUSIONS

The scale and direction of effect of PED use depend on both the epidemic disease, the public health measures enforced and how these influence decision-making. Policy makers must be aware how fear of virus among the general public may influence their response to public health advice. There is large inequity in reporting of epidemic impact on PED use which needs to be addressed.

TRIAL REGISTRATION NUMBER

CRD42021242808.

An Old Acquaintance: Could Adenoviruses Be Our Next Pandemic Threat?

Human adenoviruses (HAdV) are one of the most important pathogens detected in acute respiratory diseases in pediatrics and immunocompromised patients. In 1953, Wallace Rowe described it for the first time in oropharyngeal lymphatic tissue. To date, more than 110 types of HAdV have been described, with different cellular tropisms. They can cause respiratory and gastrointestinal symptoms, even urinary tract inflammation, although most infections are asymptomatic. However, there is a population at risk that can develop serious and even lethal conditions. These viruses have a double-stranded DNA genome, 25-48 kbp, 90 nm in diameter, without a mantle, are stable in the environment, and resistant to fat-soluble detergents. Currently the diagnosis is made with lateral flow immunochromatography or molecular biology through a polymerase chain reaction. This review aimed to highlight the HAdV variability and the pandemic potential that a HAdV3 and 7 recombinant could have considering the aggressive outbreaks produced in health facilities. Herein, we described the characteristics of HAdV, from the infection to treatment, vaccine development, and the evaluation of the social determinants of health associated with HAdV, suggesting the necessary measures for future sanitary control to prevent disasters such as the SARS-CoV-2 pandemic, with an emphasis on the use of recombinant AdV vaccines to control other potential pandemics.

Evolution in the incidence of infectious diseases in the pediatric ENT area during the COVID-19 pandemic

INTRODUCTION

SARS COV-2 infection is an emerging disease that has become a global pandemic since the beginning of 2020. To reduce transmission, measures have been imposed by governments such as home confinement, the use of masks, social distancing or promotion of hand hygiene. The aim of this study is to determine if the measures adopted to reduce the COVID-19 pandemic have produced a decrease in the incidence of infectious diseases and their complications in the ENT area in our center.

MATERIAL AND METHODS

A retrospective descriptive study was carried out in a tertiary hospital of patients aged between 0 and 15 years who required admission due to deep cervical infections, complications derived from acute otitis media (mastoiditis or facial paralysis) or complicated acute sinusitis.

RESULTS

There is a notable decrease in the number of global admissions in the COVID period (9) compared to the average of the previous 5 years (20.1). Likewise, there are statistically significant differences in the number of admissions for cervical infections (p value = 0.027) and complications derived from acute otitis media (p value = 0.029).

DISCUSSION/CONCLUSION

A decrease in the number of admissions caused by complications of infections in the ENT area in paediatric patients has been observed after the start of the COVID-19 pandemic in our environment, this fact could be explained by a global decrease in the number of infections of the upper respiratory tract due to the hygienic measures taken by the COVID-19 pandemic.

Middle Ear Condition at the Time of Pediatric Myringotomy Tube Placement: Pain Associations Following Intraoperative Fentanyl/Ketorolac and Seasonal Variation

BACKGROUND

Ketorolac-refractory pain behavior following bilateral myringotomy and pressure equalization tube placement (BMT) is associated with the absence of middle ear fluid. Intraoperative fentanyl/ketorolac affords more reliable pain control than ketorolac alone. We hypothesized that middle ear condition would correlate with postoperative pain despite such combination therapy. We further sought to demonstrate seasonal variation in ear condition and its influence on pain.

METHODS

We conducted a single-institution retrospective cohort study of healthy children (9 months-7 years), who underwent BMT by a single surgeon from 2015 to 2020. Anesthetic care included sevoflurane/nitrous oxide/oxygen/air by mask and intramuscular fentanyl/ketorolac. Left/right middle ear fluid status was recorded at the time of BMT, and ear condition (primary exposure) was dichotomized as bilateral infected (mucoid or purulent) or normal/unilateral infected. The primary outcome was maximum postanesthesia care unit Face, Legs, Activity, Cry, and Consolability (FLACC) score: 4-10 (moderate-to-severe pain) versus 0-3 (no-to-low pain). Rescue oxycodone, acetaminophen administration, and emergence agitation were secondary outcomes. Statistical analysis incorporated generalized linear mixed-effect models (GLMMs) with random intercepts to account for clustering by anesthesia provider. A year-over-year monthly time-series analysis was conducted using an autoregressive integrated moving average (ARIMA) regression model.

RESULTS

Excluding recurrent cases, 1149 unique evaluable subjects remained. Bilateral infection prevalence was 39.8% (457/1149; 95% confidence interval [CI], 37.0-42.6). Probability of moderate-to-severe pain behavior was 23.5% (270/1149; 95% CI, 21.1-26.0) overall. Compared to patients with bilateral infected middle ears, those with normal/unilateral infected ears were more likely to have a FLACC score ≥4 (26.7% [185/692] versus 18.6% [85/457]; odds ratio [95% CI], 1.7 [1.2-2.3]; P = .002). Variability in pain outcome explained by the multivariable GLMM was 4.7%. Fentanyl dose response was evidenced by oxycodone administration differences ( P ≤ 0.002). Moderate-to-severe pain and emergence agitation were more likely with reduced fentanyl dosing. Bilateral infection prevalence exhibited seasonality, peaking in March and nadiring in July. However, pain outcomes did not vary by season.

CONCLUSIONS

Normal/unilateral infected ears at time of pediatric BMT are associated with higher incidence of moderate-to-severe postoperative pain following intraoperative fentanyl/ketorolac administration, but the predictive value of ear condition on pain is limited. Infections were less common in the summer.

[Evolution in the incidence of infectious diseases in the pediatric ENT area during the COVID-19 pandemic]

INTRODUCTION

SARS COV-2 infection is an emerging disease that has become a global pandemic since the beginning of 2020. To reduce transmission, measures have been imposed by governments such as home confinement, the use of masks, social distancing or promotion of hand hygiene. The aim of this study is to determine if the measures adopted to reduce the COVID-19 pandemic have produced a decrease in the incidence of infectious diseases and their complications in the ENT area in our center.

MATERIAL AND METHODS

A retrospective descriptive study was carried out in a tertiary hospital of patients aged between 0 and 15 years who required admission due to deep cervical infections, complications derived from acute otitis media (mastoiditis or facial paralysis) or complicated acute sinusitis.

RESULTS

There is a notable decrease in the number of global admissions in the COVID period (9) compared to the average of the previous 5 years (20.1). Likewise, there are statistically significant differences in the number of admissions for cervical infections (p value= 0.027) and complications derived from acute otitis media (p value= 0.029).

DISCUSSION/CONCLUSION

A decrease in the number of admissions caused by complications of infections in the ENT area in paediatric patients has been observed after the start of the COVID-19 pandemic in our environment, this fact could be explained by a global decrease in the number of infections of the upper respiratory tract due to the hygienic measures taken by the COVID-19 pandemic.

Presentations of children to emergency departments across Europe and the COVID-19 pandemic: A multinational observational study

BACKGROUND

During the initial phase of the Coronavirus Disease 2019 (COVID-19) pandemic, reduced numbers of acutely ill or injured children presented to emergency departments (EDs). Concerns were raised about the potential for delayed and more severe presentations and an increase in diagnoses such as diabetic ketoacidosis and mental health issues. This multinational observational study aimed to study the number of children presenting to EDs across Europe during the early COVID-19 pandemic and factors influencing this and to investigate changes in severity of illness and diagnoses.

METHODS AND FINDINGS

Routine health data were extracted retrospectively from electronic patient records of children aged 18 years and under, presenting to 38 EDs in 16 European countries for the period January 2018 to May 2020, using predefined and standardized data domains. Observed and predicted numbers of ED attendances were calculated for the period February 2020 to May 2020. Poisson models and incidence rate ratios (IRRs), using predicted counts for each site as offset to adjust for case-mix differences, were used to compare age groups, diagnoses, and outcomes. Reductions in pediatric ED attendances, hospital admissions, and high triage urgencies were seen in all participating sites. ED attendances were relatively higher in countries with lower SARS-CoV-2 prevalence (IRR 2.26, 95% CI 1.90 to 2.70, p < 0.001) and in children aged <12 months (12 to <24 months IRR 0.86, 95% CI 0.84 to 0.89; 2 to <5 years IRR 0.80, 95% CI 0.78 to 0.82; 5 to <12 years IRR 0.68, 95% CI 0.67 to 0.70; 12 to 18 years IRR 0.72, 95% CI 0.70 to 0.74; versus age <12 months as reference group, p < 0.001). The lowering of pediatric intensive care admissions was not as great as that of general admissions (IRR 1.30, 95% CI 1.16 to 1.45, p < 0.001). Lower triage urgencies were reduced more than higher triage urgencies (urgent triage IRR 1.10, 95% CI 1.08 to 1.12; emergent and very urgent triage IRR 1.53, 95% CI 1.49 to 1.57; versus nonurgent triage category, p < 0.001). Reductions were highest and sustained throughout the study period for children with communicable infectious diseases. The main limitation was the retrospective nature of the study, using routine clinical data from a wide range of European hospitals and health systems.

CONCLUSIONS

Reductions in ED attendances were seen across Europe during the first COVID-19 lockdown period. More severely ill children continued to attend hospital more frequently compared to those with minor injuries and illnesses, although absolute numbers fell.

TRIAL REGISTRATION

ISRCTN91495258 https://www.isrctn.com/ISRCTN91495258.

The impact of SARS-CoV-2 on respiratory syndromic and sentinel surveillance in Israel, 2020: a new perspective on established systems

Background

The COVID-19 pandemic presented new challenges for the existing respiratory surveillance systems, and adaptations were implemented. Systematic assessment of the syndromic and sentinel surveillance platforms during the pandemic is essential for understanding the value of each platform in the context of an emerging pathogen with rapid global spread.

Aim

We aimed to evaluate systematically the performance of various respiratory syndromic surveillance platforms and the sentinel surveillance system in Israel from 1 January to 31 December 2020.

Methods

We compared the 2020 syndromic surveillance trends to those of the previous 3 years, using Poisson regression adjusted for overdispersion. To assess the performance of the sentinel clinic system as compared with the national SARS-CoV-2 repository, a cubic spline with 7 knots and 95% confidence intervals were applied to the sentinel network's weekly percentage of positive SARS-CoV-2 cases.

Results

Syndromic surveillance trends changed substantially during 2020, with a statistically significant reduction in the rates of visits to physicians and emergency departments to below previous years' levels. Morbidity patterns of the syndromic surveillance platforms were inconsistent with the progress of the pandemic, while the sentinel surveillance platform was found to reflect the national circulation of SARS-CoV-2 in the population.

Conclusion

Our findings reveal the robustness of the sentinel clinics platform for the surveillance of the main respiratory viruses during the pandemic and possibly beyond. The robustness of the sentinel clinics platform during 2020 supports its use in locations with insufficient resources for widespread testing of respiratory viruses.

The impact of the COVID-19 school closures on families with children with disabilities: A qualitative analysis

The unprecedented school closures in response to COVID-19 have been associated with a number of negative impacts on students and their families. In addition to these difficulties, parents of students with disabilities are faced with prepandemic stresses and challenges that may be exacerbated by the school closures. This qualitative study aimed to investigate the experiences and struggles of parents of children identified with a disability during the COVID-19 school closures. The 15 participants were parents of children with a range of disabilities, including Autism, Down Syndrome, ADHD, and learning disabilities. The analyses revealed four major themes: school connection, virtual learning, potential impacts for students, and managing change. The experiences of these caregivers during the COVID-19 school closures and subsequent shift to remote learning have implications for educational and treatment planning. Recommendations for how school psychologists and school teams may best support students with disabilities and their families are included.

The role of non-pharmaceutical interventions on influenza circulation during the COVID-19 pandemic in nine tropical Asian countries

Background

Low global influenza circulation was reported during the coronavirus‐19 pandemic. We explored relationships between non‐pharmaceutical interventions (NPIs) and influenza in tropical Asian countries.

Methods

Using World Health Organization (WHO) surveillance data from 2015 to 2019 and the WHO shiny app, we constructed expected seasonal influenza epidemic curves from March 2020 to June 2021 and compared the timing, and average percent positivity with observed data. We used multivariate regression to test associations between ordinal NPI data (from the Oxford Stringency Index) 4 weeks before the expected 2020/21 epidemics and present adjusted incidence rate ratio (IRR) or relative proportion ratio (RPR) and 95% confidence intervals (CI).

Results

Data from nine countries predicted 18 seasonal epidemics; seven were observed. Five started 6–24 weeks later, and all were 4–21 weeks shorter than expected. Five epidemics had lower maximum peak values (percent positivity), and all but one had lower average percent positivity than expected. All countries implemented NPIs. Each increased level of school closure reduced risk of an epidemic by 43% (IRR = 0.57, CI: 0.34, 0.95). Each increased level of canceling public events reduced the average percent positivity across the season by 44% (RPR = 0.56, CI: 0.39, 0.82) and each increased level in restricting internal movements reduced it by 41% (RPR = 0.59, CI: 0.36, 0.96). Other NPIs were not associated with changes.

Conclusions

Among nine countries, the 2020/21 seasonal epidemics were delayed, shorter, and less intense than expected. Although layered NPIs were difficult to tease apart, school closings, canceling public events, and restricting internal movements before influenza circulation seemed to reduce transmission.

Sulfurous-arsenical-ferruginous thermal water nasal inhalation and irrigation in children with recurrent upper respiratory tract infections: Clinical outcomes and predictive factors

PURPOSE

Recurrent upper respiratory disorders (RURD) are among the most common problems diagnosed in pediatric otolaryngology practice. Although several preliminary studies have demonstrated beneficial effects of thermal water inhalations for RURD, inhalation of thermal water has not been included among validated management protocols. The effects of sulfurous-arsenical-ferruginous thermal water nasal irrigations have been confirmed also in prospective, randomized studies. The main aim of this explorative, retrospective, observational study has been to compare the clinical outcome in pediatric patients with RURD treated with sulfurous-arsenical-ferruginous thermal water inhalation versus combined inhalation and nasal irrigation.

METHODS

Two hundred and fifty-three pediatric patients with RURD were considered; 231 underwent thermal water inhalations (inhalation of hot humid air and aerosol) only, while 22 underwent nasal irrigations combined with inhalations. Subjective overall efficacy perception and treatment tolerability were scored as categorical variables (from 0 = no efficacy/worst tolerability to 3 = maximal efficacy/best tolerability).

RESULTS

Nasal obstruction, sneezing, serous, mucous, and purulent rhinorrhea, cough, and snoring improved respectively in 80.2%, 72.9%, 79.0%, 93.8%, 92.3%, 64.8%, and 60.4% of patients referring these symptoms at presentation, respectively. No statistically significant differences between inhalations alone and combined inhalations and irrigations emerged. The median overall efficacy perception score was 2 while the median treatment tolerability score was 3.

CONCLUSIONS

This investigation found that sulfurous-arsenical-ferruginous water treatment was a well-tolerated therapeutic option for selected pediatric patients with RURD. These promising preliminary results should be confirmed in prospective, randomized, double-blind settings, also using minimally invasive but objective and quantitative evaluation methods.

Trends in respiratory virus circulation following COVID-19-targeted nonpharmaceutical interventions in Germany, January - September 2020: Analysis of national surveillance data

BACKGROUND

During the initial COVID-19 response, Germany's Federal Government implemented several nonpharmaceutical interventions (NPIs) that were instrumental in suppressing early exponential spread of SARS-CoV-2. NPI effect on the transmission of other respiratory viruses has not been examined at the national level thus far.

METHODS

Upper respiratory tract specimens from 3580 patients with acute respiratory infection (ARI), collected within the nationwide German ARI Sentinel, underwent RT-PCR diagnostics for multiple respiratory viruses. The observation period (weeks 1-38 of 2020) included the time before, during and after a far-reaching contact ban. Detection rates for different viruses were compared to 2017-2019 sentinel data (15350 samples; week 1-38, 11823 samples).

FINDINGS

The March 2020 contact ban, which was followed by a mask mandate, was associated with an unprecedented and sustained decline of multiple respiratory viruses. Among these, rhinovirus was the single agent that resurged to levels equalling those of previous years. Rhinovirus rebound was first observed in children, after schools and daycares had reopened. By contrast, other nonenveloped viruses (i.e. gastroenteritis viruses reported at the national level) suppressed after the shutdown did not rebound.

INTERPRETATION

Contact restrictions with a subsequent mask mandate in spring may substantially reduce respiratory virus circulation. This reduction appears sustained for most viruses, indicating that the activity of influenza and other respiratory viruses during the subsequent winter season might be low,whereas rhinovirus resurgence, potentially driven by transmission in educational institutions in a setting of waning population immunity, might signal predominance of rhinovirus-related ARIs.

FUNDING

Robert Koch-Institute and German Ministry of Health.

COVID-19 and School: To Open or Not to Open, That Is the Question. The First Review on Current Knowledge

The COVID-19 pandemic has led to an unprecedented closure of schools in terms of duration. The option of school closure, SARS-CoV-2 initially being poorly known, was influenced by the epidemiological aspects of the influenza virus. However, school closure is still under debate and seems unsupported by sure evidence of efficacy in the COVID-19 era. The aim of our narrative review is to discuss the available literature on SARS-CoV-2 spread among children and adolescents, in the school setting, trying to explain why children appear less susceptible to severe disease and less involved in viral spreading. We also tried to define the efficacy of school closure, through an overview of the effects of the choices made by the various countries, trying to identify which preventive measures could be effective for a safe reopening. Finally, we focused on the psychological aspects of such a prolonged closure for children and adolescents. SARS-CoV-2, children, COVID-19, influenza, and school were used as key words in our literature research, updated to 29 March 2021. To our knowledge, this is the first review summarizing the whole current knowledge on SARS-CoV-2 spreading among children and adolescents in the school setting, providing a worldwide overview in such a pandemic context.

COVID-19: Effects of lockdown on adenotonsillar hypertrophy and related diseases in children

BACKGROUND

In response to the coronavirus pandemic 2019 (COVID-19), Italy established the national school closings from March 5, 2020. It has been shown that during school closures, there are significant decreases in the diagnoses of the respiratory infections. This has brought as well to a reduction in all those symptoms related to adenotonsillar hypertrophy.

METHODS

The study included 162 children, aged between 3 and 13 years, waiting for adenoidectomy and/or tonsillectomy, eventually combined with tympanocentesis or tube insertion. Parents have been called to answer a telephone interview aimed at detecting how the symptoms related to adenotonsillar hypertrophy were changing during lockdown.

RESULTS

There was an improvement in the overall symptomatology of children during the lockdown period. The value attributed by parents to the children's general assessment during the lockdown period decreased significatively during the quarantine (p = 0,0000).

CONCLUSIONS

The present study demonstrates that lockdown can have a positive impact on those specific diseases derived from precocious socialization and that it results to be particularly effective for the most vulnerable children. Indeed, lockdown has resulted to be so efficient that it has caused a modification in a medical and surgical therapeutic indication.

The impact of unplanned school closure on children's social contact: rapid evidence review

BackgroundEmergency school closures are often used as public health interventions during infectious disease outbreaks to minimise the spread of infection. However, if children continue mixing with others outside the home during closures, the effect of these measures may be limited.AimThis review aimed to summarise existing literature on children's activities and contacts made outside the home during unplanned school closures.MethodsIn February 2020, we searched four databases, MEDLINE, PsycInfo, Embase and Web of Science, from inception to 5 February 2020 for papers published in English or Italian in peer-reviewed journals reporting on primary research exploring children's social activities during unplanned school closures. Main findings were extracted.ResultsA total of 3,343 citations were screened and 19 included in the review. Activities and social contacts appeared to decrease during closures, but contact remained common. All studies reported children leaving the home or being cared for by non-household members. There was some evidence that older child age (two studies) and parental disagreement (two studies) with closure were predictive of children leaving the home, and mixed evidence regarding the relationship between infection status and such. Parental agreement with closure was generally high, but some disagreed because of perceived low risk of infection and issues regarding childcare and financial impact.ConclusionEvidence suggests that many children continue to leave home and mix with others during school closures despite public health recommendations to avoid social contact. This review of behaviour during unplanned school closures could be used to improve infectious disease modelling.

The impact of unplanned school closure on children's social contact: rapid evidence review

BackgroundEmergency school closures are often used as public health interventions during infectious disease outbreaks to minimise the spread of infection. However, if children continue mixing with others outside the home during closures, the effect of these measures may be limited.AimThis review aimed to summarise existing literature on children's activities and contacts made outside the home during unplanned school closures.MethodsIn February 2020, we searched four databases, MEDLINE, PsycInfo, Embase and Web of Science, from inception to 5 February 2020 for papers published in English or Italian in peer-reviewed journals reporting on primary research exploring children's social activities during unplanned school closures. Main findings were extracted.ResultsA total of 3,343 citations were screened and 19 included in the review. Activities and social contacts appeared to decrease during closures, but contact remained common. All studies reported children leaving the home or being cared for by non-household members. There was some evidence that older child age (two studies) and parental disagreement (two studies) with closure were predictive of children leaving the home, and mixed evidence regarding the relationship between infection status and such. Parental agreement with closure was generally high, but some disagreed because of perceived low risk of infection and issues regarding childcare and financial impact.ConclusionEvidence suggests that many children continue to leave home and mix with others during school closures despite public health recommendations to avoid social contact. This review of behaviour during unplanned school closures could be used to improve infectious disease modelling.

School dismissal as a pandemic influenza response: When, where and for how long?

We used individual-based computer simulation models at community, regional and national levels to evaluate the likely impact of coordinated pre-emptive school dismissal policies during an influenza pandemic. Such policies involve three key decisions: when, over what geographical scale, and how long to keep schools closed. Our evaluation includes uncertainty and sensitivity analyses, as well as model output uncertainties arising from variability in serial intervals and presumed modifications of social contacts during school dismissal periods. During the period before vaccines become widely available, school dismissals are particularly effective in delaying the epidemic peak, typically by 4–6 days for each additional week of dismissal. Assuming the surveillance is able to correctly and promptly diagnose at least 5–10% of symptomatic individuals within the jurisdiction, dismissals at the city or county level yield the greatest reduction in disease incidence for a given dismissal duration for all but the most severe pandemic scenarios considered here. Broader (multi-county) dismissals should be considered for the most severe and fast-spreading (1918-like) pandemics, in which multi-month closures may be necessary to delay the epidemic peak sufficiently to allow for vaccines to be implemented.

Analysing the link between public transport use and airborne transmission: mobility and contagion in the London underground

BACKGROUND

The transmission of infectious diseases is dependent on the amount and nature of contacts between infectious and healthy individuals. Confined and crowded environments that people visit in their day-to-day life (such as town squares, business districts, transport hubs, etc) can act as hot-spots for spreading disease. In this study we explore the link between the use of public transport and the spread of airborne infections in urban environments.

METHODS

We study a large number of journeys on the London Underground, which is known to be particularly crowded at certain times. We use publically available Oyster card data (the electronic ticket used for public transport in Greater London), to infer passengers' routes on the underground network. In order to estimate the spread of a generic airborne disease in each station, we use and extend an analytical microscopic model that was initially designed to study people moving in a corridor.

RESULTS

Comparing our results with influenza-like illnesses (ILI) data collected by Public Health England (PHE) in London boroughs, shows a correlation between the use of public transport and the spread of ILI. Specifically, we show that passengers departing from boroughs with higher ILI rates have higher number of contacts when travelling on the underground. Moreover, by comparing our results with other demographic key factors, we are able to discuss the role that the Underground plays in the spread of airborne infections in the English capital.

CONCLUSIONS

Our study suggests a link between public transport use and infectious diseases transmission and encourages further research into that area. Results could be used to inform the development of non-pharmacological interventions that can act on preventing instead of curing infections and are, potentially, more cost-effective.

School closure during novel influenza: A systematic review

BACKGROUND

School closure as a non-pharmaceutical measure appeared as an efficient strategy in previous epidemics. We investigated the impact of school closure on the epidemic peak whether implemented before or after the epidemic reaches its peak. We also investigated the optimal duration of closure.

METHODS

Data sources included Medline-PubMed, ProQuest and Cochrane databases. The inclusion criteria were all articles that reported a quantified effect on school closure on an influenza epidemic. Exclusion criteria were non-English articles that have no translation and articles that only reported school closure effect as a combination with another measure. Out of 668 articles, we included 31 articles.

RESULTS

The mean reduction of the peak of the epidemic was M=29.65%. Implementing school closure before or after the epidemic reaches its peak reduced the overall influenza epidemic. School closure reduced and delayed the epidemic peak especially if implemented earlier. The longer the duration of closure the more the epidemic peak delayed. Additionally, closure containment effect also correlated with organisms having high attack rate and longer infectiveness duration.

CONCLUSION

We conclude with several implications for school closure taking into consideration the feasibility and the cost.

The impact of regular school closure on seasonal influenza epidemics: a data-driven spatial transmission model for Belgium

BACKGROUND

School closure is often considered as an option to mitigate influenza epidemics because of its potential to reduce transmission in children and then in the community. The policy is still however highly debated because of controversial evidence. Moreover, the specific mechanisms leading to mitigation are not clearly identified.

METHODS

We introduced a stochastic spatial age-specific metapopulation model to assess the role of holiday-associated behavioral changes and how they affect seasonal influenza dynamics. The model is applied to Belgium, parameterized with country-specific data on social mixing and travel, and calibrated to the 2008/2009 influenza season. It includes behavioral changes occurring during weekend vs. weekday, and holiday vs. school-term. Several experimental scenarios are explored to identify the relevant social and behavioral mechanisms.

RESULTS

Stochastic numerical simulations show that holidays considerably delay the peak of the season and mitigate its impact. Changes in mixing patterns are responsible for the observed effects, whereas changes in travel behavior do not alter the epidemic. Weekends are important in slowing down the season by periodically dampening transmission. Christmas holidays have the largest impact on the epidemic, however later school breaks may help in reducing the epidemic size, stressing the importance of considering the full calendar. An extension of the Christmas holiday of 1 week may further mitigate the epidemic.

CONCLUSION

Changes in the way individuals establish contacts during holidays are the key ingredient explaining the mitigating effect of regular school closure. Our findings highlight the need to quantify these changes in different demographic and epidemic contexts in order to provide accurate and reliable evaluations of closure effectiveness. They also suggest strategic policies in the distribution of holiday periods to minimize the epidemic impact.

Explaining the geographical origins of seasonal influenza A (H3N2)

Most antigenically novel and evolutionarily successful strains of seasonal influenza A (H3N2) originate in East, South and Southeast Asia. To understand this pattern, we simulated the ecological and evolutionary dynamics of influenza in a host metapopulation representing the temperate north, tropics and temperate south. Although seasonality and air traffic are frequently used to explain global migratory patterns of influenza, we find that other factors may have a comparable or greater impact. Notably, a region's basic reproductive number (R0) strongly affects the antigenic evolution of its viral population and the probability that its strains will spread and fix globally: a 17-28% higher R0 in one region can explain the observed patterns. Seasonality, in contrast, increases the probability that a tropical (less seasonal) population will export evolutionarily successful strains but alone does not predict that these strains will be antigenically advanced. The relative sizes of different host populations, their birth and death rates, and the region in which H3N2 first appears affect influenza's phylogeography in different but relatively minor ways. These results suggest general principles that dictate the spatial dynamics of antigenically evolving pathogens and offer predictions for how changes in human ecology might affect influenza evolution.

Social and Economic Impacts of School Influenza Outbreaks in England: Survey of Caregivers

BACKGROUND

Influenza is a cause of considerable morbidity in England, particularly among children. A total of 39% of all influenza-attributable general practitioner consultations and 37% of all influenza-attributable hospital admissions occur in those aged under 15 years. Few studies have quantified the impact of influenza outbreaks on families. We assessed this impact during 2 influenza seasons.

METHODS

We used questionnaires to obtain data in primary schools that reported an outbreak of an influenza-like-illness (ILI). We sought data on the loss of productivity, costs borne by families and loss in health-related quality of life (HRQoL). ILIs were identified using the symptoms criteria from the European Centre for Disease Prevention and Control and the UK Flusurvey.

RESULTS

For each child reporting ILI, mean school absence was 3.8 days (95% confidence interval [CI]): 3.0-4.8) with mean work absence for caregivers reported as 3.7 days (95% CI: 2.7-4.8). The mean loss in HRQoL was 2.1 quality-adjusted life days (95% CI: 1.5-2.7). The estimated total pediatric burden of disease for reported school-based outbreaks during the 2 influenza seasons was 105.3 QALYs (95% CI: 77.7-139.0).

CONCLUSIONS

This study shows the potential social and economic benefit of vaccination of children during mild influenza seasons.

Brief communication (Original). Effectiveness of influenza control using nonpharmaceutical interventions at primary schools in Nakhon Phanom Province, Northeast Thailand

Background: The world is entering the post-outbreak period of the 2009 A H1N1 strain of the influenza virus. The strain is expected to continue spreading, as seasonal influenza viruses do each year. The majority of children have relatively low immunity and engage in activities at school where opportunities abound for exposure to and spreading of diseases.

Objectives: We compared the effectiveness of influenza prevention by using non-pharmaceutical measures in primary schools.

Methods: This study was conducted at two medium-sized primary schools in Nakhon Phanom province, Thailand. Multistage sampling was used to select students from Grades 4 to 6. The study group consisted of 230 students from the 2 schools and the control group 224 students from the 2 schools. The research included (a) 8 h of instruction on influenza-like illnesses and their prevention integrated into health promotion and physical education classes and (b) building understanding among parents and in the community. Data were analyzed for frequencies, percentages, and multiple logistic regression.

Results: Non-pharmaceutical influenza interventions reduced the rate of influenza-like illnesses by 77% (AOR = 0.23, 95% CI: 0.15"0.36). Students who did not receive the influenza-like prevention and control training had a morbidity of 54.9%; whereas those who received the training had a morbidity of 23.5%. Overall, the group receiving the educational model saw a 57% reduction in its morbidity compared with the control group. The students in the intervention group who washed their hands for 20 seconds three or more times per day had a morbidity of 38.9%, which resulted in an overall reduction in morbidity of 36.4%. The morbidity rate of students who missed school because they were ill was 39.5%. When comparing training methods, the hand-washing group saw morbidity reduced by 34.7%, while simply receiving news and information from public health officials resulted in only a 29.2% reduction in morbidity. Overall, the group receiving the disease prevention and control training was able to reduce morbidity by 58.7%.

Conclusion: Influenza prevention education among students was integrated into the health education curriculum. Children were taught hand-washing and respiratory etiquette (i.e., covering the nose and face when sneezing, coughing, and nose-blowing). Cartoon media were used as visual teaching aids. The results from this program helped to decrease the number of cases of influenza-like illness and morbidity among students and families.

Influence of School Year on Seasonality of Norovirus Outbreaks in Developed Countries

Factors affecting the seasonal distribution of norovirus outbreaks are not well understood. This study examined whether grade school settings at the start of the school year may be a factor. We searched Ovid Medline from January 2002 to June 2014 for studies that provided all reported norovirus outbreaks in a developed country by month for a minimum of three years. Historical school years were obtained from verifiable sources. The start of the norovirus seasonal outbreak peak and peak outbreak month were determined for each study and compared to the start month of school. Northern hemisphere and southern hemisphere countries had a different norovirus seasonality and different school year structures (traditional compared to year round). In the two studies that provided outbreaks by age, outbreaks among children started several months before outbreaks in the adult population. The median number of months between school start and start of the seasonal outbreak peak was two months (interquartile range [IQR] = 2.0-3.0), while the median number of months between school start and peak outbreak month was four months (IQR = 3.0-4.0). These findings suggest the possibility the school setting at the start of the school year may be a factor in the seasonality of norovirus.

Effects of meteorologic factors and schooling on the seasonality of group A streptococcal pharyngitis

The objective of this study was to determine the seasonal pattern of group A streptococcal pharyngitis in children attended at a hospital emergency department in the Mediterranean island of Mallorca (Spain), and its association with meteorologic factors and schooling. We conducted a retrospective review of the medical records of children aged 1-15 years with a diagnosis of Streptococcus pyogenes pharyngitis between January 2006 and December 2011. The number of S. pyogenes pharyngitis was correlated to temperature, humidity, rainfall, atmospheric pressure, wind speed, solar radiation, and schooling, using regression and time series techniques. A total of 906 patients (median, 4 years old) with S. pyogenes pharyngitis, confirmed by throat culture, were attended during the study period. A seasonal pattern was observed with a peak activity in June and a minimum in September. Mean temperature, solar radiation, and school holidays were the best predicting variables (R(2) = 0.68; p < 0.001). S. pyogenes activity increased with the decrease of mean temperature (z = -2.4; p < 0.05), the increase of solar radiation (z = 4.2; p < 0.001), and/or the decrease in school holidays (z = -2.4; p < 0.05). In conclusion, S. pyogenes pharyngitis had a clear seasonality predominating in springtime, and an association with mean temperature, solar radiation, and schooling was observed. The resulting model predicted 68 % of S. pyogenes pharyngitis.

Targeted vaccination in healthy school children - Can primary school vaccination alone control influenza?

BACKGROUND

The UK commenced an extension to the seasonal influenza vaccination policy in autumn 2014 that will eventually see all healthy children between the ages of 2-16 years offered annual influenza vaccination. Models suggest that the new policy will be both highly effective at reducing the burden of influenza as well as cost-effective. We explore whether targeting vaccination at either primary or secondary schools would be more effective and/or cost-effective than the current strategy.

METHODS

An age-structured deterministic transmission dynamic SEIR-type mathematical model was used to simulate a national influenza outbreak in England. Costs including GP consultations, hospitalisations due to influenza and vaccinations were compared to potential gains in quality-adjusted life years achieved through vaccinating healthy children. Costs and benefits of the new JCVI vaccination policy were estimated over a single season, and compared to the hypothesised new policies of targeted and heterogeneous vaccination.

FINDINGS AND CONCLUSION

All potential vaccination policies were highly cost-effective. Influenza transmission can be eliminated for a particular season by vaccinating both primary and secondary school children, but not by vaccinating only one group. The most cost-effective policy overall is heterogeneous vaccination coverage with 48% uptake in primary schools and 34% in secondary schools. The Joint Committee on Vaccination and Immunisation can consider a modification to their policy of offering seasonal influenza vaccinations to all healthy children of ages 2-16 years.

Back-to-school upper respiratory infection in preschool and primary school-age children in Israel

BACKGROUND

Increased upper respiratory infection (URI) among children at the beginning of school year is well known to parents and pediatricians. However, this phenomenon is not well documented or characterized.

METHODS

Computerized datasets from a large health maintenance organization in Israel were used to calculate the weekly rates of URI among children 3-14 years old for the years 2007-2012. In addition, nasopharyngeal swabs were collected in 2010-2012 from children with URI symptoms and controls during school opening time. Swabs were tested by real-time polymerase chain reaction for the presence of respiratory viruses.

RESULTS

Time-series analysis demonstrated a peak of URI in September each year. The peaks reached their height 2 weeks after school opening and returned to baseline within 4-7 weeks. The main 3 viruses detected both in URI patients and in healthy controls during the first weeks of school opening were rhinovirus, adenovirus and enterovirus. The detection rate of any respiratory virus, and of rhinovirus in particular, was significantly higher among cases than among controls (54% vs. 16%, P < 0.001 for any virus, and 35% vs. 6.0%, P < 0.01 for rhinovirus). When adjusting for age and sex cases had 5.8 times more viral detection when compared with controls. Upper respiratory symptoms were significantly more prevalent among the virus-positive cases when compared with negative ones.

CONCLUSIONS

Back-to-school illness consisting of URI has a distinct epidemiological pattern demonstrating a rapid rise peaking within 2 weeks of school opening and is associated predominantly with rhinovirus.

Rates of influenza-like illness and winter school breaks, Chile, 2004-2010

To determine effects of school breaks on influenza virus transmission in the Southern Hemisphere, we analyzed 2004-2010 influenza-like-illness surveillance data from Chile. Winter breaks were significantly associated with a two-thirds temporary incidence reduction among schoolchildren, which supports use of school closure to temporarily reduce illness, especially among schoolchildren, in the Southern Hemisphere.

Effect of individual protective behaviors on influenza transmission: an agent-based model

It is well established in the epidemiological literature that individual behaviors have a significant effect on the spread of infectious diseases. Agent-based models are increasingly being recognized as the next generation of epidemiological models. In this research, we use the ability of agent-based models to incorporate behavior into simulations by examining the relative importance of vaccination and social distancing, two common measures for controlling the spread of infectious diseases, with respect to seasonal influenza. We modeled health behaviour using the result of a Health Belief Model study focused on influenza. We considered a control and a treatment group to explore the effect of education on people's health-related behaviors patterns. The control group reflects the behavioral patterns of students based on their general knowledge of influenza and its interventions while the treatment group illustrates the level of behavioral changes after individuals have been educated by a health care expert. The results of this study indicate that self-initiated behaviors are successful in controlling an outbreak in a high contact rate location such as a university. Self-initiated behaviors resulted in a population attack rate decrease of 17% and a 25% reduction in the peak number of cases. The simulation also provides significant evidence for the effect of an HBM theory-based educational program to increase the rate of applying the target interventions (vaccination by 22% percent and social distancing by 41%) and consequently to control the outbreak.

Mitigation of infectious disease at school: targeted class closure vs school closure

Background

School environments are thought to play an important role in the community spread of infectious diseases such as influenza because of the high mixing rates of school children. The closure of schools has therefore been proposed as an efficient mitigation strategy. Such measures come however with high associated social and economic costs, making alternative, less disruptive interventions highly desirable. The recent availability of high-resolution contact network data from school environments provides an opportunity to design models of micro-interventions and compare the outcomes of alternative mitigation measures.

Methods and results

We model mitigation measures that involve the targeted closure of school classes or grades based on readily available information such as the number of symptomatic infectious children in a class. We focus on the specific case of a primary school for which we have high-resolution data on the close-range interactions of children and teachers. We simulate the spread of an influenza-like illness in this population by using an SEIR model with asymptomatics, and compare the outcomes of different mitigation strategies. We find that targeted class closure affords strong mitigation effects: closing a class for a fixed period of time – equal to the sum of the average infectious and latent durations – whenever two infectious individuals are detected in that class decreases the attack rate by almost 70% and significantly decreases the probability of a severe outbreak. The closure of all classes of the same grade mitigates the spread almost as much as closing the whole school.

Conclusions

Our model of targeted class closure strategies based on readily available information on symptomatic subjects and on limited information on mixing patterns, such as the grade structure of the school, shows that these strategies might be almost as effective as whole-school closure, at a much lower cost. This may inform public health policies for the management and mitigation of influenza-like outbreaks in the community.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0695-9) contains supplementary material, which is available to authorized users.

Positive network assortativity of influenza vaccination at a high school: implications for outbreak risk and herd immunity

Schools are known to play a significant role in the spread of influenza. High vaccination coverage can reduce infectious disease spread within schools and the wider community through vaccine-induced immunity in vaccinated individuals and through the indirect effects afforded by herd immunity. In general, herd immunity is greatest when vaccination coverage is highest, but clusters of unvaccinated individuals can reduce herd immunity. Here, we empirically assess the extent of such clustering by measuring whether vaccinated individuals are randomly distributed or demonstrate positive assortativity across a United States high school contact network. Using computational models based on these empirical measurements, we further assess the impact of assortativity on influenza disease dynamics. We found that the contact network was positively assortative with respect to influenza vaccination: unvaccinated individuals tended to be in contact more often with other unvaccinated individuals than with vaccinated individuals, and these effects were most pronounced when we analyzed contact data collected over multiple days. Of note, unvaccinated males contributed substantially more than unvaccinated females towards the measured positive vaccination assortativity. Influenza simulation models using a positively assortative network resulted in larger average outbreak size, and outbreaks were more likely, compared to an otherwise identical network where vaccinated individuals were not clustered. These findings highlight the importance of understanding and addressing heterogeneities in seasonal influenza vaccine uptake for prevention of large, protracted school-based outbreaks of influenza, in addition to continued efforts to increase overall vaccine coverage.

The influence of school holiday timing on epidemic impact

The impact of reactive school closure on an epidemic is uncertain, since it is not clear how an unplanned closure will affect social mixing patterns. The effect of school holidays on social mixing patterns is better understood. Here, we use mathematical models to explore the influence of the timing of school holidays on the final size and peak incidence of an influenza-like epidemic. A well-timed holiday can reduce the impact of an epidemic, in particular substantially reducing an epidemic's peak. Final size and peak incidence cannot both be minimized: a later holiday is optimal for minimizing the final size, while an earlier holiday minimizes peak incidence. Using social mixing data from the UK, we estimated that, had the 2009 influenza epidemic not been interrupted by the school summer holidays, the final size would have been about 20% larger and the peak about 170% higher.

Effect of winter school breaks on influenza-like illness, Argentina, 2005-2008

School closures are used to reduce seasonal and pandemic influenza transmission, yet evidence of their effectiveness is sparse. In Argentina, annual winter school breaks occur during the influenza season, providing an opportunity to study this intervention. We used 2005-2008 national weekly surveillance data of visits to a health care provider for influenza-like illness (ILI) from all provinces. Using Serfling-specified Poisson regressions and population-based census denominators, we developed incidence rate ratios (IRRs) for the 3 weeks before, 2 weeks during, and 3 weeks after the break. For persons 5-64 years of age, IRRs were <1 for at least 1 week after the break. Observed rates returned to expected by the third week after the break; overall decrease among persons of all ages was 14%. The largest decrease was among children 5-14 years of age during the week after the break (37% lower IRR). Among adults, effects were weaker and delayed. Two-week winter school breaks significantly decreased visits to a health care provider for ILI among school-aged children and nonelderly adults.

Current initiatives to improve prudent antibiotic use amongst school-aged children

High rates of antimicrobial prescribing for children, combined with widespread misunderstanding among the general public about the appropriate use of antibiotics, are major causes for concern. European Antibiotic Awareness Day (EAAD) is an annual event that aims to raise awareness of how to use antibiotics in a responsible way that will help keep them effective for the future. As part of EAAD 2013, this article provides an overview of some initiatives aimed at limiting the extent of inappropriate antibiotic use in children.

Effective school actions for mitigating seasonal influenza outbreaks in Niigata, Japan

Background

Japan has implemented various school actions during seasonal influenza outbreaks since the 1950's under the School Health Law. However, the effective duration, extent, and timing of closures remain unresolved.

Materials and Methods

We conducted a retrospective study on the relationship between elementary class closures and influenza outbreak control during four consecutive influenza seasons from the 2004-2005 to 2007-2008 school years in Joetsu, Niigata, Japan. Among a total of 1,061 classes of 72 schools, 624 cases of influenza outbreaks were documented among 61 schools.

Results

Class closures were carried out in a total of 62 cases in response to influenza outbreak, which was defined as a student absentee rate of greater than 10% due to influenza or influenza-like illness. Of these cases, two-day class closures were conducted the day after reaching a 10% student absentee rate in 28 cases and other types of closures were initiated in 34 cases. A markedly higher number of outbreak cases ended within one week for two-day class closures compared to the other types of closures (82.1% vs. 20.6%, respectively). The significant association between two-day class closures and interruption of an outbreak within one week was confirmed using a multivariable model adjusted for the season, grade, day of the week of an outbreak start, and absentee rate on the day of an outbreak start (OR, 3.18; 95% CI, 1.12–9.07; p = 0.030).

Conclusions

Our results suggest that a two-day class closure carried out the day after reaching a 10% absentee rate is an effective approach for mitigating influenza outbreaks in elementary schools.

Physician attitudes regarding school-located vaccination clinics

BACKGROUND

School-located vaccination clinics offer an opportunity to target children for vaccination programs during communicable disease outbreaks. However, children in the United States are primarily vaccinated in the pediatrician's or family physician's office, and the concept of school-located vaccinations may be unfamiliar to some parents and guardians. Physician support could contribute to effective implementation of school-located vaccination clinics during outbreak situations. The primary objective of the study was to assess physician opinion of using school-located vaccination clinics to administer both outbreak-specific and routine vaccines.

METHODS

A statewide mail and Internet survey was administered to 275 pediatricians and 275 family physicians in Oregon during July and August 2010.

RESULTS

Ninety-one percent of physicians supported the use of school-located vaccination clinics as immunization delivery sites during outbreak situations. Sixty percent of physicians supported using school-located vaccination clinics to administer routine vaccinations. Only 57% of physicians had knowledge of school-located vaccination clinic availability to their patients.

CONCLUSIONS

Pediatricians and family physicians expressed strong support of school vaccination clinics as sites for immunization delivery during outbreak situations but significantly less support for administering routine vaccinations. Increasing physician awareness of school-located vaccination clinic availability and establishing partnerships between physician practices and school vaccination clinics may improve access to immunizations for school-aged children and adolescents, particularly during large-scale communicable disease outbreaks.

School closures and influenza: systematic review of epidemiological studies

OBJECTIVE

To review the effects of school closures on pandemic and seasonal influenza outbreaks.

DESIGN

Systematic review.

DATA SOURCES

MEDLINE and EMBASE, reference lists of identified articles, hand searches of key journals and additional papers from the authors' collections.

STUDY SELECTION

Studies were included if they reported on a seasonal or pandemic influenza outbreak coinciding with a planned or unplanned school closure.

RESULTS

Of 2579 papers identified through MEDLINE and EMBASE, 65 were eligible for inclusion in the review along with 14 identified from other sources. Influenza incidence frequently declined after school closure. The effect was sometimes reversed when schools reopened, supporting a causal role for school closure in reducing incidence. Any benefits associated with school closure appeared to be greatest among school-aged children. However, as schools often closed late in the outbreak or other interventions were used concurrently, it was sometimes unclear how much school closure contributed to the reductions in incidence.

CONCLUSIONS

School closures appear to have the potential to reduce influenza transmission, but the heterogeneity in the data available means that the optimum strategy (eg, the ideal length and timing of closure) remains unclear.

Household economic impact and attitudes toward school closures in two cities in Argentina during the 2009 influenza A (H1N1) pandemic

Please cite this paper as: Basurto‐Dávila et al. (2012) Household economic impact and attitudes toward school closures in two cities in Argentina during the 2009 influenza A (H1N1) pandemic. Influenza and Other Respiratory Viruses. DOI: 10.1111/irv.12054.

Background  School closures were widely implemented in Argentina during the 2009 H1N1 influenza virus pandemic.

Objectives  To assess the economic impact of school closures on households, their effectiveness in preventing children from engaging in social group activities, and parental attitudes toward them.

Methods  Three schools that closed for 2 weeks in response to the pandemic were identified in two socioeconomically distinct cities in Argentina. All households with children enrolled in these schools were surveyed. Direct and indirect costs attributable to closures were estimated from the household perspective. Other information collected included children activities during the closures and parental attitudes toward the intervention.

Results  Completed questionnaires were returned by 45% of surveyed households. Direct and indirect costs due to closures represented 11% of imputed monthly household income in the city with lower socioeconomic status, and 3% in the other city (P = 0·01). Non‐childcare expenses and loss of workdays were more common in the city with lower socioeconomic status. Childcare expenses were less common and were experienced by a similar percentage of households in both cities. About three‐quarters of respondents in both cities agreed with the closures. The main concern among those who disagreed with closures was their negative impact on education. Children in more than two‐thirds of affected households left their home at least once during the closures to spend time in public places.

Conclusion  School closures may more significantly impact low‐income households. Authorities should consider the range of economic impacts of school closures among families when planning their implementation.

The effectiveness of U.S. public health surveillance systems for situational awareness during the 2009 H1N1 pandemic: a retrospective analysis

BACKGROUND

The 2009 H1N1 outbreak provides an opportunity to learn about the strengths and weaknesses of current U.S. public health surveillance systems and to identify implications for measuring public health emergency preparedness.

METHODOLOGY/PRINCIPAL FINDINGS

We adopted a "triangulation" approach in which multiple contemporary data sources, each with different expected biases, are compared to identify time patterns that are likely to reflect biases versus those that are more likely to be indicative of actual infection rates. This approach is grounded in the understanding that surveillance data are the result of a series of decisions made by patients, health care providers, and public health professionals about seeking and providing health care and about reporting cases to health authorities. Although limited by the lack of a gold standard, this analysis suggests that children and young adults are over-represented in many pH1N1 surveillance systems, especially in the spring wave. In addition, the nearly two-month delay between the Northeast and the South in the Fall peak in some surveillance data seems to at least partially reflect regional differences in concerns about pH1N1 rather than real differences in pH1N1 infection rates.

CONCLUSIONS/SIGNIFICANCE

Although the extent of the biases suggested by this analysis cannot be known precisely, the analysis identifies underlying problems with surveillance systems--in particular their dependence on patient and provider behavior, which is influenced by a changing information environment--that could limit situational awareness in future public health emergencies. To improve situational awareness in future health emergencies, population-based surveillance systems such as telephone surveys of representative population samples and seroprevalence surveys in well-defined population cohorts are needed.

Two years after pandemic influenza A/2009/H1N1: what have we learned?

The world had been anticipating another influenza pandemic since the last one in 1968. The pandemic influenza A H1N1 2009 virus (A/2009/H1N1) finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Because of the persistent threat from the A/H5N1 virus since 1997 and the outbreak of the severe acute respiratory syndrome (SARS) coronavirus in 2003, medical and scientific communities have been more prepared in mindset and infrastructure. This preparedness has allowed for rapid and effective research on the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the disease, with impacts on its control. A PubMed search using the keywords "pandemic influenza virus H1N1 2009" yielded over 2,500 publications, which markedly exceeded the number published on previous pandemics. Only representative works with relevance to clinical microbiology and infectious diseases are reviewed in this article. A significant increase in the understanding of this virus and the disease within such a short amount of time has allowed for the timely development of diagnostic tests, treatments, and preventive measures. These findings could prove useful for future randomized controlled clinical trials and the epidemiological control of future pandemics.

School absenteeism as an adjunct surveillance indicator: experience during the second wave of the 2009 H1N1 pandemic in Quebec, Canada

Background

A school absenteeism surveillance system was implemented in the province of Quebec, Canada during the second wave of the 2009 H1N1pandemic. This paper compares this surveillance approach with other available indicators.

Method

All (3432) elementary and high schools from Quebec were included. Each school was required to report through a web-based system any day where the proportion of students absent for influenza-like illness (ILI) exceeded 10% of current school enrolment.

Results

Between October 18 and December 12 2009, 35.6% of all schools met the 10% absenteeism threshold. This proportion was greater in elementary compared to high schools (40% vs 19%) and in smaller compared to larger schools (44% vs 22%). The maximum absenteeism rate was reached the first day of reporting or within the next two days in 55% and 31% of schools respectively. The first reports and subsequent peak in school absenteeism provincially preceded the peak in paediatric hospitalization by two and one weeks, respectively. Trends in school surveillance otherwise mirrored other indicators.

Conclusion

During a pandemic, school outbreak surveillance based on a 10% threshold appears insufficient to trigger timely intervention within a given affected school. However, school surveillance appears well-correlated and slightly anticipatory compared to other population indicators. As such, school absenteeism warrants further evaluation as an adjunct surveillance indicator whose overall utility will depend upon specified objectives, and other existing capacity for monitoring and response.

Influenza transmission in a community during a seasonal influenza A(H3N2) outbreak (2010-2011) in Mongolia: a community-based prospective cohort study

Background

Knowledge of how influenza viruses spread in a community is important for planning and implementation of effective interventions, including social distancing measures. Households and schools are implicated as the major sites for influenza virus transmission. However, the overall picture of community transmission is not well defined during actual outbreaks. We conducted a community-based prospective cohort study to describe the transmission characteristics of influenza in Mongolia.

Methods and Findings

A total of 5,655 residents in 1,343 households were included in this cohort study. An active search for cases of influenza-like illness (ILI) was performed between October 2010 and April 2011. Data collected during a community outbreak of influenza A(H3N2) were analyzed. Total 282 ILI cases occurred during this period, and 73% of the subjects were aged <15 years. The highest attack rate (20.4%) was in those aged 1–4 years, whereas the attack rate in those aged 5–9 years was 10.8%. Fifty-one secondary cases occurred among 900 household contacts from 43 households (43 index cases), giving an overall crude household secondary attack rate (SAR) of 5.7%. SAR was significantly higher in younger household contacts (relative risk for those aged <1 year: 9.90, 1–4 years: 5.59, and 5–9 years: 6.43). We analyzed the transmission patterns among households and a community and repeated transmissions were detected between households, preschools, and schools. Children aged 1–4 years played an important role in influenza transmission in households and in the community at large. Working-age adults were also a source of influenza in households, whereas elderly cases (aged ≥65 years) had no link with household transmission.

Conclusions

Repeated transmissions between households, preschools, and schools were observed during an influenza A(H3N2) outbreak period in Mongolia, where subjects aged 1–4 years played an important role in influenza transmission.

Evaluating temporal factors in combined interventions of workforce shift and school closure for mitigating the spread of influenza

Background

It is believed that combined interventions may be more effective than individual interventions in mitigating epidemic. However there is a lack of quantitative studies on performance of the combination of individual interventions under different temporal settings.

Methodology/Principal Findings

To better understand the problem, we develop an individual-based simulation model running on top of contact networks based on real-life contact data in Singapore. We model and evaluate the spread of influenza epidemic with intervention strategies of workforce shift and its combination with school closure, and examine the impacts of temporal factors, namely the trigger threshold and the duration of an intervention. By comparing simulation results for intervention scenarios with different temporal factors, we find that combined interventions do not always outperform individual interventions and are more effective only when the duration is longer than 6 weeks or school closure is triggered at the 5% threshold; combined interventions may be more effective if school closure starts first when the duration is less than 4 weeks or workforce shift starts first when the duration is longer than 4 weeks.

Conclusions/Significance

We therefore conclude that identifying the appropriate timing configuration is crucial for achieving optimal or near optimal performance in mitigating the spread of influenza epidemic. The results of this study are useful to policy makers in deliberating and planning individual and combined interventions.