Exploring Usability of School Closure Data for Influenza-Like Illness Surveillance

We compared tempOral patterns of respiratory illness-related unplanned school closures (USC) with influenza-like illness (ILI) data from outpatient provider visits to determine usability of these data for additional insight regarding ILI activity. We found significant correlation between USC and ILINet data (R= 0.54 with p-value <0.0001). The occurrence pattern of respiratory illness-related USCs similarly corresponded with that of ILI activity regardless of the severity of influenza season. This suggests that monitoring USCs can be a useful addition to existing influenza surveillance systems, particularly during severe influenza seasons when respiratory illness-related USCs may occur more frequently

School closures due to seasonal influenza: a prospective data collection-based study of eleven influenza seasons—United States, 2011–2022Research in context

Summary: Background: While numerous studies explore pandemic-associated school closures, literature is scant regarding seasonal influenza-associated closures. We previously reported summaries on COVID-19 pandemic-related school closures in the United States (US), which affected virtually all schools in the nation. The current prospective study aims to address the knowledge gap for seasonal influenza-related closures in the United States. Methods: We conducted systematic daily online searches from August 1, 2011 to June 30, 2022, to identify public announcements of unplanned school closures in the US lasting ≥1 day, selecting those that mentioned influenza and influenza-like illness (ILI) as reason for school closure (ILI-SCs). We studied ILI-SC temporal patterns and compared them with reported outpatient ILI-related healthcare visits. Findings: We documented that ILI-SCs occurred annually, with yearly totals ranging from 11 ILI-SCs in both the 2013–2014 and 2020–2021 school years to 2886 ILI-SCs in the 2019–2020 school year among more than 100,000 kindergarten through twelfth grade schools in the US. ILI-SCs occurred concurrently with widespread illness and the strongest correlations were observed during influenza A (H3N2)-dominant seasons, most notably in the 2016–2017 (Spearman rank correlation (rs) = 0.83) and the 2017–2018 (rs = 0.84) school years. ILI-SCs were heavily centered in U.S. Department of Health and Human Services Region 4 (states of Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee) [60% (6040/9166, Region 4/Total school closures)] and disproportionately impacted rural and lower-income communities. Interpretation: Outside of a pandemic, disease-related school closures are extreme and generally rare events for US schools and communities. Timely compilation of publicly available ILI-SC announcements could enhance influenza surveillance, particularly in severe influenza seasons or pandemics when ILI-SCs are prevalent. Funding: This work was supported by the U.S. Centers for Disease Control and Prevention. Co-authors (NZ, YZ, HG, AU) were or are US CDC employees, and FJ was a contractor through Cherokee Nation Operational Solutions, LLC, which supported FJ’s salary, but had no additional role in the study

Unplanned School Closures in the United States: Evaluation of Economic and Social Costs and Consequences for Students’ Families

School closures implemented pre-emptively, before the peak of influenza activity, are an effective mitigation strategy to slow disease transmission during influenza pandemic. Prolonged school closures may impose unintended economic and social costs to students families. To better understand this unintended impact, we conducted household surveys in five different regions of the United States following school closures implemented for various reasons. One of the primary challenges for families during unplanned school closures is making emergency childcare arrangements. While the most frequently childcare is provided by a non-working household member, this option is not available for families where all adults are employed full-time. Although disruption of subsidized school lunch program did not appear as a difficulty for the majority of eligible families during these school closures, more research might be needed on closures that last longer than 7 days.

Comparing Observed with Predicted Weekly Influenza-Like Illness Rates during the Winter Holiday Break, United States, 2004-2013.

In the United States, influenza season typically begins in October or November, peaks in February, and tapers off in April. During the winter holiday break, from the end of December to the beginning of January, changes in social mixing patterns, healthcare-seeking behaviors, and surveillance reporting could affect influenza-like illness (ILI) rates. We compared predicted with observed weekly ILI to examine trends around the winter break period. We examined weekly rates of ILI by region in the United States from influenza season 2003-2004 to 2012-2013. We compared observed and predicted ILI rates from week 44 to week 8 of each influenza season using the auto-regressive integrated moving average (ARIMA) method. Of 1,530 region, week, and year combinations, 64 observed ILI rates were significantly higher than predicted by the model. Of these, 21 occurred during the typical winter holiday break period (weeks 51-52); 12 occurred during influenza season 2012-2013. There were 46 observed ILI rates that were significantly lower than predicted. Of these, 16 occurred after the typical holiday break during week 1, eight of which occurred during season 2012-2013. Of 90 (10 HHS regions x 9 seasons) predictions during the peak week, 78 predicted ILI rates were lower than observed. Out of 73 predictions for the post-peak week, 62 ILI rates were higher than observed. There were 53 out of 73 models that had lower peak and higher post-peak predicted ILI rates than were actually observed. While most regions had ILI rates higher than predicted during winter holiday break and lower than predicted after the break during the 2012-2013 season, overall there was not a consistent relationship between observed and predicted ILI around the winter holiday break during the other influenza seasons

Temporal Association between ILI and the Winter Holiday Break, U.S. 2004-2012

The difference between observed and predicted ILI rates during the winter holiday period varies across HHS region and influenza seasons. Most frequently, the last week in December had higher observed than predicted ILI rates, and the first week of January had lower observed than predicted ILI rates

Utility of Nontraditional Data Sources for Early Detection of Influenza

ObjectiveThis session will provide an overview of the current systemsfor influenza surveillance; review the role of schools in influenzatransmission; discuss relationships between school closures, schoolabsenteeism, and influenza transmission; and explore the usefulnessof school absenteeism and unplanned school closure monitoring forearly detection of influenza in schools and broader communities.IntroductionInfluenza surveillance is conducted through a complex networkof laboratory and epidemiologic systems essential for estimatingpopulation burden of disease, selecting influenza vaccine viruses,and detecting novel influenza viruses with pandemic potential (1).Influenza surveillance faces numerous challenges, such as constantlychanging influenza viruses, substantial variability in the number ofaffected people and the severity of disease, nonspecific symptoms,and need for laboratory testing to confirm diagnosis. Exploringadditional components that provide morbidity information mayenhance current influenza surveillance.School-aged children have the highest influenza incidence ratesamong all age groups. Due to the close interaction of children inschools and subsequent introduction of influenza into households,it is recognized that schools can serve as amplification points ofinfluenza transmission in communities. For this reason, pandemicpreparedness recommendations include possible pre-emptive schoolclosures, before transmission is widespread within a school system orbroader community, to slow influenza transmission until appropriatevaccines become available. During seasonal influenza epidemics,school closures are usually reactive, implemented in response tohigh absenteeism of students and staff after the disease is alreadywidespread in the community. Reactive closures are often too late toreduce influenza transmission and are ineffective.To enhance timely influenza detection, a variety of nontraditionaldata sources have been explored. School absenteeism was suggestedby several research groups to improve school-based influenzasurveillance. A study conducted in Japan demonstrated that influenza-associated absenteeism can predict influenza outbreaks with highsensitivity and specificity (2). Another study found the use of all-causes absenteeism to be too nonspecific for utility in influenzasurveillance (3). Creation of school-based early warning systemsfor pandemic influenza remains an interest, and further studies areneeded. The panel will discuss how school-based surveillance cancomplement existing influenza surveillance systems

School practices to promote social distancing in K-12 schools: review of influenza pandemic policies and practices

Abstract Background During an evolving influenza pandemic, community mitigation strategies, such as social distancing, can slow down virus transmission in schools and surrounding communities. To date, research on school practices to promote social distancing in primary and secondary schools has focused on prolonged school closure, with little attention paid to the identification and feasibility of other more sustainable interventions. To develop a list and typology of school practices that have been proposed and/or implemented in an influenza pandemic and to uncover any barriers identified, lessons learned from their use, and documented impacts. Methods We conducted a review of the peer-reviewed and grey literature on social distancing interventions in schools other than school closure. We also collected state government guidance documents directed to local education agencies or schools to assess state policies regarding social distancing. We collected standardized information from each document using an abstraction form and generated descriptive statistics on common plan elements. Results The document review revealed limited literature on school practices to promote social distancing, as well as limited incorporation of school practices to promote social distancing into state government guidance documents. Among the 38 states that had guidance documents that met inclusion criteria, fewer than half (42%) mentioned a single school practice to promote social distancing, and none provided any substantive detail about the policies or practices needed to enact them. The most frequently identified school practices were cancelling or postponing after-school activities, canceling classes or activities with a high rate of mixing/contact that occur within the school day, and reducing mixing during transport. Conclusion Little information is available to schools to develop policies and procedures on social distancing. Additional research and guidance are needed to assess the feasibility and effectiveness of school practices to promote social distancing

Effect of 4-Day School District Closure on Influenza-Like Illness Rates Among Students and Household Members - Kentucky, 2013

High rates of absences from influenza-like-illness (ILI) resulted in closure of a Kentucky school district for 4-days during the 2012-2013 influenza season. We calculated average daily rates of household ILI as recalled in paper surveys by parents for the weeks before, during, and after the closure. Average daily rates of ILI in the district that closed were not significantly reduced when compared with rates in 2 surrounding school districts that did not close

Effect of 4-Day School District Closure on Influenza-Like Illness Rates Among Students and Household Members - Kentucky, 2013

High rates of absences from influenza-like-illness (ILI) resulted in closure of a Kentucky school district for 4-days during the 2012-2013 influenza season. We calculated average daily rates of household ILI as recalled in paper surveys by parents for the weeks before, during, and after the closure. Average daily rates of ILI in the district that closed were not significantly reduced when compared with rates in 2 surrounding school districts that did not close

Sentiment score of relevant posts identified from social media by date.

<p>Relevant posts mentioned impact of unplanned school closure due to Chicago teachers’ strike from September 8–21 (two days before to three days after strike) on students and their families (N = 930). Sentiment score was calculated as: (positive posts—negative posts)/(positive posts + negative posts + neutral posts)^a-b. ^aSentiment score < 0 suggests negative sentiment; score > 0 suggests positive sentiment. ^bScore on September 21 reflects only four relevant posts, all expressing negative sentiment.</p