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School Closure and Mitigation of Pandemic (H1N1) 2009, Hong Kong
Abstract
In Hong Kong, kindergartens and primary schools were closed when local transmission of pandemic (H1N1) 2009 was identified. Secondary schools closed for summer vacation shortly afterwards. By fitting a model of reporting and transmission to case data, we estimated that transmission was reduced approximately 25% when secondary schools closed.
Supplementary resource (1)
Data
March 2010
... We identified 4 relevant studies that considered the effect of screening on influenza transmission, including 2 epidemiologic studies from the 2009 pandemic (10,11) and 2 simulation studies (12,13). The epidemiologic studies estimated that entry screening delayed the arrival of influenza A(H1N1)pdm09 virus to previously unaffected areas by an average of 7-12 days (11) and delayed the epidemic in China by 4 days by reducing imported cases by 37% from border entry screening (10). The simulation studies predicted that entry screening would delay the arrival of infection into a country by a few days or 1-2 weeks at most (12,13). ...
... We did not systematically review studies of the technical performance of various screening tools (e.g., screening case definitions and thermal scanners) but identified in an informal search 4 studies that discussed the challenges of screening travelers for infection, which include limited screening sensitivity (10,11,13), an incubation period of 1-7 days for influenza A(H1N1)pdm09 virus (meaning some infected travelers might not show symptoms until after arrival at their destination) (10,12,13), limited local capacity of influenza surveillance (10,11), and limited public health resources, such as laboratory capacity and funding (10,11,13). ...
... We did not systematically review studies of the technical performance of various screening tools (e.g., screening case definitions and thermal scanners) but identified in an informal search 4 studies that discussed the challenges of screening travelers for infection, which include limited screening sensitivity (10,11,13), an incubation period of 1-7 days for influenza A(H1N1)pdm09 virus (meaning some infected travelers might not show symptoms until after arrival at their destination) (10,12,13), limited local capacity of influenza surveillance (10,11), and limited public health resources, such as laboratory capacity and funding (10,11,13). ...
International travel-related nonpharmaceutical interventions (NPIs), which can include traveler screening, travel restrictions, and border closures, often are included in national influenza pandemic preparedness plans. We performed systematic reviews to identify evidence for their effectiveness. We found 15 studies in total. Some studies reported that NPIs could delay the introduction of influenza virus. However, no available evidence indicated that screening of inbound travelers would have a substantial effect on preventing spread of pandemic influenza, and no studies examining exit screening were found. Some studies reported that travel restrictions could delay the start of local transmission and slow international spread, and 1 study indicated that small Pacific islands were able to prevent importation of pandemic influenza during 1918-19 through complete border closure. This limited evidence base indicates that international travel-related NPIs would have limited effectiveness in controlling pandemic influenza and that these measures require considerable resources to implement.
... Such a reduction could have a large effect on transmission, given a typical reproduction number of 1.2-1.4 for seasonal influenza [10]. Our results are comparable to previous studies on reactive school closures, where reductions of 16%-25% in influenza transmission were reported [8,11]. The overall reductions in influenza transmission during the spring breaks were highest among the school-aged children, consistent with the findings of previous studies [11,12]. ...
... Our results are comparable to previous studies on reactive school closures, where reductions of 16%-25% in influenza transmission were reported [8,11]. The overall reductions in influenza transmission during the spring breaks were highest among the school-aged children, consistent with the findings of previous studies [11,12]. Our estimates are likely to provide a lower bound for the effect of preemptive school closures around the epidemic peak, during which the general population would be more likely to adopt enhanced preventive measures and other social distancing measures [12]. ...
School closures are considered as a potential non-pharmaceutical intervention to mitigate severe influenza epidemics and pandemics. In this study, we assessed the effects of scheduled school closure on influenza transmission, using influenza surveillance data before, during, and after spring breaks in South Korea, 2014-2016. During the spring breaks, influenza transmission was reduced by 27-39%, while overall reduction in transmissibility was estimated by 6-23%, with greater effects observed among school-aged children.
... School closures are a common measure of pandemic mitigation for many countries, driven by the logic that social distancing reduces transmission. [1][2][3] Although school closures are known to reduce transmission, previous works have suggested that school closures could have downstream consequences on the healthcare system such as healthcare worker absenteeism. 4,5 However, lack of granular, high-resolution data has restrained previous studies to providing estimates based on national data with strong assumptions, underscoring the need for more detailed analysis. ...
... To identify a potential approach to reducing absenteeism, we estimated that the vast majority of counties (> 98%) could save money by providing child care to their healthcare workers with children in the event of a school closure (ω > 1). Although it is likely that many child care avenues would also be closed in the event of school closures, subsidized child care costs could still prevent absenteeism by (1) incentivizing work attendance with extra wages, and (2) alleviating the financial burden on the entire household, enabling other family or household members to participate in child care. ...
Background
School closures have been enacted as a measure of mitigation during the ongoing COVID-19 pandemic. It has been shown that school closures could cause absenteeism amongst healthcare workers with dependent children, but there remains a need for spatially granular analyses of the relationship between school closures and healthcare worker absenteeism to inform local community preparedness.
Methods
We provide national- and county-level simulations of school closures and unmet child care needs across the United States. We develop individual simulations using county-level demographic and occupational data, and model school closure effectiveness with age-structured compartmental models. We perform multivariate quasi-Poisson ecological regressions to find associations between unmet child care needs and COVID-19 vulnerability factors.
Results
At the national level, we estimate the projected rate of unmet child care needs for healthcare worker households to range from 7.5% to 8.6%, and the effectiveness of school closures to range from 3.2% ( R 0 = 4) to 7.2% ( R 0 = 2) reduction in fewer ICU beds at peak demand. At the county-level, we find substantial variations of projected unmet child care needs and school closure effects, ranging from 1.9% to 18.3% of healthcare worker households and 5.7% to 8.8% reduction in fewer ICU beds at peak demand ( R 0 = 2). We find significant positive associations between estimated levels of unmet child care needs and diabetes prevalence, county rurality, and race ( p < 0.05). We estimate costs of absenteeism and child care and observe from our models that an estimated 71.1% to 98.8% of counties would find it less expensive to provide child care to all healthcare workers with children than to bear the costs of healthcare worker absenteeism during school closures.
Conclusions
School closures are projected to reduce peak ICU bed demand, but could disrupt healthcare systems through absenteeism, especially in counties that are already particularly vulnerable to COVID-19. Child care subsidies could help circumvent the ostensible tradeoff between school closures and healthcare worker absenteeism.
... The COVID-19 pandemic presents an interesting historical moment, something scholars have now understand as a consequential societal crisis, especially for education (Wodon 2020;Lancker and Parolin 2020). Schools have to time and again responded to different forms of crises: pandemics like the 2009 A(H1N1) influenza and the 2020 COVID-19 viruses (Azevedo et al. 2020;Wu et al. 2010;Cauchemez et al. 2014), economic recessions like the 2008 Great Recession and the Greek economic crisis (Goldhaber et al. 2016;Hatzichristou, Lianos, and Lampropoulou 2017), and wars like those in South Sudan, Sierra Leone, Afghanistan and Syria, and the consequences for refugees and children (Sommers 2002;Tooley and Longfield 2017;McCarthy 2018). Often, the concern is for how schools can continue to serve its purpose of educating children, given the constraints forced upon by different crises. ...
... A situation that closely resembles the 2020 pandemic is the 2009 influenza A(H1N1) pandemic that had also led to school closures around the world, with consequences on reducing human-to-human virus transmission (Wu et al. 2010); cancelling classes and school activities altogether (Uscher-Pines et al. 2018); incurring economic costs in terms of lost productivity, work absenteeism, and childcare costs (Sadique, Adams, and Edmunds 2008;Brown et al. 2011); and exacerbating academic and social inequalities for children from vulnerable populations Berkman 2008). In terms of organisational studies on school closures during the 2009 A(H1N1) pandemic, the focus was mainly on national and local actors that decide on the policy to close schools (Cauchemez et al. 2014). ...
The coronavirus disease 2019 (COVID-19) has disrupted and posed great challenges for kindergarten-grade12 education systems. Initial studies on education and COVID-19 often focus on technology use, student learning, and school reopening plans. However, debates on the form of instruction become futile when stakeholders are unclear about what the competing values, issues, and priorities are. Using exploratory data analysis of a representative sample of US teachers and school leaders, this paper highlights key organisational issues and priorities in terms of addressing academic achievement gaps, students' online engagement, and teachers' and students' health. More fundamentally, deeper issues are uncovered like equity for those doubly disadvantaged by the pandemic, student engagement in the face of more pressing concerns, and health both physical and mental. More theoretically, the research contributes to understanding schools' responses to societal crises and the need to clarify competing values during decision-making in the face of such crises. ARTICLE HISTORY
... Although there were cases confirmed on or before January 16, the official diagnostic protocol was released by WHO on January 17 [8]. To adjust the impact of this event, we considered a time-varying reporting rate that follows a linear increasing trend, motivated by the previous study [9]. We assumed that the reporting rate, r(t), started increasing since January 17, and stopped at the maximal level at January 20. ...
Backgrounds
An ongoing outbreak of a novel coronavirus (2019-nCoV) pneumonia hit a major city of China, Wuhan, December 2019 and subsequently reached other provinces/regions of China and countries. We present estimates of the basic reproduction number, R 0 , of 2019-nCoV in the early phase of the outbreak.
Methods
Accounting for the impact of the variations in disease reporting rate, we modelled the epidemic curve of 2019-nCoV cases time series, in mainland China from January 10 to January 24, 2020, through the exponential growth. With the estimated intrinsic growth rate ( γ ), we estimated R 0 by using the serial intervals (SI) of two other well-known coronavirus diseases, MERS and SARS, as approximations for the true unknown SI.
Findings
The early outbreak data largely follows the exponential growth. We estimated that the mean R 0 ranges from 2.24 (95%CI: 1.96-2.55) to 3.58 (95%CI: 2.89-4.39) associated with 8-fold to 2-fold increase in the reporting rate. We demonstrated that changes in reporting rate substantially affect estimates of R 0 .
Conclusion
The mean estimate of R 0 for the 2019-nCoV ranges from 2.24 to 3.58, and significantly larger than 1. Our findings indicate the potential of 2019-nCoV to cause outbreaks.
... A correlation analysis between weekly mortality rates and interventions (which included school closure) during the 1918-19 pandemic in cities in the United States estimated that early and sustained interventions reduced mortality rates by <25% (29). Two studies conducted in Hong Kong as a public health response to influenza A(H1N1)pdm09 estimated that school closures, followed by planned school holidays, reduced influenza transmission (30,31). ...
Influenza virus infections are believed to spread mostly by close contact in the community. Social distancing measures are essential components of the public health response to influenza pandemics. The objective of these mitigation measures is to reduce transmission, thereby delaying the epidemic peak, reducing the size of the epidemic peak, and spreading cases over a longer time to relieve pressure on the healthcare system. We conducted systematic reviews of the evidence base for effectiveness of multiple mitigation measures: isolating ill persons, contact tracing, quarantining exposed persons, school closures, workplace measures/closures, and avoiding crowding. Evidence supporting the effectiveness of these measures was obtained largely from observational studies and simulation studies. Voluntary isolation at home might be a more feasible social distancing measure, and pandemic plans should consider how to facilitate this measure. More drastic social distancing measures might be reserved for severe pandemics.
... 32,33 , the incubation period of the CoVs are generally similar. ...
The notorious novel coronavirus has been causing various cases of pneumonia outbreak starting in Wuhan, Hubei province in China and spreading throughout the world. This paper presents a study of the information available on the outbreak, to provide a deeper understanding of the origin, transmission and danger of this newly discovered virus. The basic reproduction rate (R0) is focused on to understand the transmission pattern of this virus. Results obtained from the studies conducted by various parties have been collected and compared. It is believed that this virus is highly related with the SARS-CoV and MERS-CoV that happened during 2003 and 2012, respectively, hence a lot of preliminary studies are based on these as there is lack of sufficient data specific to COVID-19. Studies reported R0 within the range of 2-5, indicating that each infected patient will transmit the virus to 2-5 other individuals.
... 5 A mitigation strategy limits infection spread to a slowed and controlled rate, such as school closings, which slowed infection rates during the mitigation effort in Hong Kong's battle against the H1N1 pandemic in 2009. 6 A suppression strategy attempts to reduce infections, lowering R 0 to <1 and shrinking or eliminating the outbreak through tactics such as lockdowns and stay-at-home or shelter-in-place directives on a wide scale-often national. Suppression is the clearly stated government goal for dealing with COVID-19 (striving to have long periods of zero infection spread) in locations such as New Zealand, South Korea, Vietnam, Taiwan, and China. ...
During the COVID-19 pandemic, government social marketing messages support strategies of suppression (often stay-at-home orders or lockdowns) and/or mitigation (through testing, isolation, and tracing). Success at lowering the virus reproduction rate (R0) depends on social marketing messaging that rapidly changes behaviors. This study explores a potential side effect of a successful antivirus public health messaging campaign, when employees are back at work but the virus threat has not disappeared, that leads to on-the-job stress. The authors surveyed office employees in Shanghai, the People's Republic of China, where a nearly 2-month COVID-19 quarantine ended in late March 2020 and work locations reopened with strong public health messaging to encourage cooperation with continued virus spread suppression strategies-an approach likely to be followed in numerous countries. This study examines the relationship of pandemic public messaging sensitivity with tension and negative emotions on the job. Canonical correlation analysis is used with a sample of 1154 respondents, 4 predictor variables (reference group, self-regulation, media, and risk), and 2 criterion variables (negative emotions and job tension). Results show employees are differentially affected by the pandemic background noise. Those more sensitive to social-level virus risks and more open to reference group influence report increased levels of negative emotions and work tension.
... This, in effect, dilutes the effectiveness of the closures. School children, for example, are known to act as maintenance hosts of influenza, and therefore the rationale for school closure is to reduce contact and subsequent transmission among children and in the social scene within the school setting (Mizumoto, Yamamoto, & Nishiura, 2013;Wu, Cowling, Lau et al., 2010). Table 3 gives a summary of behavioural tendencies that need to be highly discouraged among adults and children. ...
By incorporating emotionality, this paper proposes to enrich cognitive information processing among the general public in times of crisis as evident in COVID-19. Two distinct emotional responses namely fear and anxiety with sufficient enthusiasm profoundly influences our behaviour and responses towards the disease. Fear because the threat of the coronavirus disease is real, and anxiety because of the novelty that stimulates our utmost attention toward COVID-19. The anxiety powerfully influences preferences and stimulates our involvement in the COVID-19 health and wellness campaign. The discussion enhances a phenomenological theoretical perspective concerning cognitive and emotional processes as mutually engaged and in turn supportive as countries and the public adopt various intervention measures aimed at curbing the spread of the COVID-19 pandemic. The discussions demonstrate the cognitive information process and fathoms out how people can appropriately practice emotions as tools towards dealing with the fear and anxiety of COVID-19.
... Data from France show that seasonal holidays prevent some 16-18% of influenza cases 9 and research in Hong Kong on the seasonal outbreak in 2008, 10 the H1N1 pandemic in 2009, 11 and the seasonal outbreak in 2018 12 suggests some impact for school closures during influenza pandemics, but only where schools close in time. ...
... This, in effect, dilutes the effectiveness of the closures. School children, for example, are known to act as maintenance hosts of influenza, and therefore the rationale for school closure is to reduce contact and subsequent transmission among children and in the social scene within the school setting (Mizumoto, Yamamoto, & Nishiura, 2013;Wu, Cowling, Lau et al., 2010). Table 3 gives a summary of behavioural tendencies that need to be encouraged among adults and children. ...
Since COVID-19 was announced in China in December 2019, the pandemic has become a central focus all over the World. Despite the extent of the crisis with initial high death rates in China, Italy and Spain, there exists a wishful fantasy in the low-and middle-income countries that the population will be somehow protected from the extreme anguish and pain. This is even though the more developing countries have tended to have critical problems such as perennial drought, cancer, political instability and war, poverty and ill health, including communicable disease and HIV/AIDS. Although other issues have been placed in the periphery amidst the corona epidemic, there is an obvious need to identify and comprehend in psychological terms various intervention strategies to deal with the pandemic. Besides, some of the similarities in dealing with the pandemic are astonishing. Most of these countries are former colonies and display common patterns aimed at controlling the population using the military forces, including the adoption of curfews and lockdowns. This builds up high levels of intolerable pressure and a depressed attitude, often culminating in stress, fear and anxiety. This paper proposes a comprehensive conceptual approach to this phenomenon and the underlying psychological concerns. pandemic has become a central focus all over the World. Despite the extent of the crisis with initial high death rates in China, Italy and Spain, there exists a wishful fantasy in the low-and middle-income countries in Africa and Asia that the population will somehow be protected from the extreme suffering and pain as a result of COVID-19. Besides, the more developing countries
... To limit the spread of influenza, school closures are one of the most effective social distancing measures available . The impact of school closures against influenza transmission has been discussed in modeling and epidemiological studies (Cauchemez et al. 2008;Wu et al. 2010a). Transmission has sometimes rebounded when schools are reopened, indirectly indicating that the closures had been suppressing influenza transmission Ryu et al. 2020a). ...
Influenza virus infections are common in people of all ages. Epidemics occur in the winter months in temperate locations and at varying times of the year in subtropical and tropical locations. Most influenza virus infections cause mild and self-limiting disease, and around one-half of all infections occur with a fever. Only a small minority of infections lead to serious disease requiring hospitalization. During epidemics, the rates of influenza virus infections are typically highest in school-age children. The clinical severity of infections tends to increase at the extremes of age and with the presence of underlying medical conditions, and impact of epidemics is greatest in these groups. Vaccination is the most effective measure to prevent infections, and in recent years influenza vaccines have become the most frequently used vaccines in the world. Nonpharmaceutical public health measures can also be effective in reducing transmission, allowing suppression or mitigation of influenza epidemics and pandemics.
... In an analysis of surveillance data and school holiday schedules in France between 1985 and 2006, Cauchemez et al. estimated that seasonal school holidays prevented 16-18% of seasonal influenza cases. 1 Wu et al. estimated that influenza transmission was reduced by 25% during the 2009 influenza pandemic in Hong Kong when secondary schools closed. 2 Children are underrepresented in COVID-19 case statistics 3 and are less likely to become seriously ill or die. [4][5][6] In a retrospective cohort study of 13,323 COVID-19 cases reported in Italy between February 20 and March 15, 2020, Livingston and Bucher reported that children aged 0 to 18 years accounted for 1.2% of cases and that no deaths were recorded. ...
Background
Children are underrepresented in COVID-19 case statistics and are less likely to become seriously ill or die. Early studies suggested that the evidence to support school closure to contain the COVID-19 pandemic was weak and that SARS-CoV-2 transmission was low in Australian schools during the early stages of the pandemic. This caused some to prematurely conclude that children are considerably less important drivers of SARS-CoV-2 transmission than adults. However, recent reports suggested high viral loads in nasopharyngeal swabs of symptomatic young children, and high transmission among children and adolescents attending an overnight youth camp.
Questions
What is the role of children in SARS-CoV-2 transmission?
Findings
Contact tracing studies reported that children younger than 10 years of age are less likely to test positive for SARS-CoV-2. These studies can underestimate the infection rate in children if infected children are more likely to be asymptomatic than infected adults. In a retrospective analysis of outbreak investigations in Ontario, young children were three times more likely to be asymptomatic after SARS-CoV-2 infection than older individuals. Seroprevalence studies found young children less likely to have antibodies against SARS-CoV-2. These studies were conducted when schools had been closed, therefore children were likely to have fewer social contacts than during regular school schedules.
A biological explanation for the potential lower susceptibility of younger children to SARS-CoV-2 infection could be a lower density of ACE2, the receptor used by SARS-CoV-2 to infect cells, in the nasal mucosa. However, if children have more social contacts or react differently to public health interventions than adults, this could offset the potential biological advantage offered by lower ACE2 density.
A retrospective cohort study of an outbreak in attendees of an overnight youth camp found younger children were at least as likely as older attendees to be infected with SARS-CoV-2. This suggests that young children can have attack rates similar to those of older children, adolescents and adults under conditions that are conducive to outbreaks, such as high local transmission and overnight stays in dormitories. SARS-CoV-2 RNA levels in swabs from children and adolescents with COVID-19 are similar to those in adults with COVID-19, and infectious SARS-CoV-2 was detected in children of all ages. Ecological studies found that school closures were associated with a containment of the COVID-19 pandemic, but it was not possible to disentangle the independent impact of school closures from the impact of other public health interventions. Case studies of school openings in different countries suggest that school openings can be safe provided that local transmission is low and appropriate measures are in place to prevent or contain potential outbreaks in schools.
Interpretation
Early suggestions that children are considerably less important drivers of SARS-CoV-2 transmission than adults are not confirmed by more recent research. Children could play a relevant role in SARS-CoV-2 transmission and school closures may have been important contributors to the containment of the COVID-19 pandemic. Public health interventions could be as relevant and impactful to control transmission in children as in adults. It appears therefore important to include children as part of any surveillance, testing and control strategy, while bearing in mind that children are more likely than adults to remain asymptomatic after SARS-CoV-2 infection.
... School closures are one of many non-pharmaceutical interventions that can be employed during epidemics of droplet infections, such as influenza, to reduce transmission, and can be highly effective [1][2][3] . However, there are substantial societal and economic costs associated with closing large numbers of schools, such as limiting children's access to education and requiring caregivers to stay at home (impacting on household income and on economic activity) [4][5][6][7][8] , which can affect deprived households most 9 . ...
Background
School closures are a well-established non-pharmaceutical intervention in the event of infectious disease outbreaks, and have been implemented in many countries across the world, including the UK, to slow down the spread of SARS-CoV-2. As governments begin to relax restrictions on public life there is a need to understand the potential impact that reopening schools may have on transmission.
Methods
We used data provided by the UK Department for Education to construct a network of English schools, connected through pairs of pupils resident at the same address. We used the network to evaluate the potential for transmission between schools, and for long range propagation across the network, under different reopening scenarios.
Results
Amongst the options evaluated we found that reopening only Reception, Year 1 and Year 6 (4-6 and 10-11 year olds) resulted in the lowest risk of transmission between schools, with outbreaks within a single school unlikely to result in outbreaks in adjacent schools in the network. The additional reopening of Years 10 and 12 (14-15 and 16-17 year olds) resulted in an increase in the risk of transmission between schools comparable to reopening all primary school years (4-11 year olds). However, the majority of schools presented low risk of initiating widespread transmission through the school system. Reopening all secondary school years (11-18 year olds) resulted in large potential outbreak clusters putting up to 50% of households connected to schools at risk of infection if sustained transmission within schools was possible.
Conclusions
Reopening secondary school years is likely to have a greater impact on community transmission than reopening primary schools in England. Keeping transmission within schools limited is essential for reducing the risk of large outbreaks amongst school-aged children and their household members.
... However, further studies are warranted to explore evidence for these two speculative hypotheses. This study proposed an analytical approach to construct the instantaneous rCFR that can be adopted to further examine the associations with its potential determinants, e.g., pathogenic evolution, change in the cases ascertainment rate (Nishiura et al., 2020;Wu et al., 2010;, the supply of critical care resources , and exposure to the environmental factors (Yao et al., 2020). ...
The case fatality ratio (CFR) is one of the key measurements to evaluate the clinical severity of infectious diseases. The CFR may vary due to change in factors that affect the mortality risk. In this study, we developed a simple likelihood-based framework to estimate the instantaneous CFR of infectious diseases. We used the publicly available COVID-19 surveillance data in Canada as a demonstrative example. The mean fatality ratio of reported COVID-19 cases (rCFR) in Canada was estimated at 6.9% (95%CI: 4.5–10.6). We emphasize the extensive implementation of the constructed instantaneous CFR that is to identify the key determinants affecting the mortality risk.
... In Mexico, the source country for the 2009 H1N1 pandemic, schools closed for 14 days from April 27 to May 10 (Herrera-Valdez et al. 2011). Targeted, city levels closures during the H1N1 pandemic were seen in Bangkok, Thailand -three weeks (Chieochansin et al. 2009), Auckland, New Zealand -four days (Stuart et al. 2013), and Hong Kong -one month (Wu et al. 2010). Information on school closures for the 1918-1919 In uenza Pandemic that killed at least 50 million people and infected one-third of the global population (CDC nd) is di cult to nd. ...
The COVID-19 pandemic has seen an unprecedented shutdown of society. Nearly 1.725 billion children across the globe have been affected as over 95% of countries closed schools as the virus spread in April 2020. Much attention has been given to school closures as non-pharmaceutical mitigation tools to stem the spread of the disease through ensuring social distancing. Within education, focus has been given to keep students connected through remote learning and the immediate needs of schools upon reopening. This study takes a longer-term view. Using Demographic Health Surveys and Multiple Indicator Cluster Surveys from before and after the 2013-2016 Ebola outbreak in Guinea and Sierra Leone, this study examines changes in enrolment and dropout patterns, with targeted consideration given to traditionally marginalized groups. With schools closed for seven and nine months in the two countries, the length and intensity of the Ebola pandemic is the only health crises in the past century to come close to the school closures being experienced in 2020. Findings suggest that youth in the poorest households see the largest increase in dropout rates post-Ebola and that this impact can persist for years. Two years after being declared Ebola-free an additional 22,000 of the poorest secondary age youth remained out of school than would have been expected based on the pre-outbreak dropout rate. To halt the likely expansion in inequality post-pandemic, these results point to the need for longer term, sustainable planning that includes comprehensive financial support packages to groups most likely to be impacted.
... Regardless of pharmacological interventions, non-pharmacological interventions have an important role in delaying the epidemic, reducing its peak, and the prevalence of new cases over time (4). Non-pharmaceutical interventions (NPI) goes beyond such measures as self-isolation (SI), such as quarantining infected populations, closing borders, schools and workplaces, washing hands; cleaning surfaces; etc. (5). ...
Context: Worldwide outbreak of coronavirus has been declared by the World Health Organization as a global emergency. Quarantine, as one of the first important health measures to control and spread epidemic diseases, is the focus of health authorities and policymakers in most societies. This study was designed to obtain the psychological impact of quarantine and strategies to reduce it. Evidence Acquisition: This is a “narrative review” study done through advanced search with the keywords Quarantine, Home isolation, COVID-19, Coronavirus, Mental Health, Psychological effect in the Scopus, Pumped, Clinical Key, Google Scholar, ScienceDirect, Web of Science databases from 2019-2020. The articles were included in the study according to the inclusion and exclusion criteria. Systematic searching and screening of the titles resulted in 68 initial titles that decreased to 46 after reviewing the abstracts, and 19 articles were included in the final review. Results: Quarantine can lead to psychosocial problems from feeling lonely to depression and anxiety disorders. Certain counseling, as well as educational and supportive interventions, can make this situation tolerable. Conclusions: For acceptance and adherence to quarantine conditions, clear and transparent information about the disease and its prevalence and meeting the needs of people such as psychological, informational, and financial needs in each country are essential to reduce fear and anxiety.
... An important aim for policymakers near the start of an outbreak is to assess the risk posed by the invading pathogen, including whether initial cases will lead to a major epidemic or whether the pathogen will die out rapidly instead [8,9]. An important practical consequence is that, if an outbreak is likely simply to fade out, then costly interventions such as vaccination [10,11], culling/felling/roguing of plants or agricultural animals [12][13][14][15][16][17][18] and workplace or school closure [19] may be unnecessary [20]. ...
Forecasting whether or not initial reports of disease will be followed by a severe epidemic is an important component of disease management. Standard epidemic risk estimates involve assuming that infections occur according to a branching process and correspond to the probability that the outbreak persists beyond the initial stochastic phase. However, an alternative assessment is to predict whether or not initial cases will lead to a severe epidemic in which available control resources are exceeded. We show how this risk can be estimated by considering three practically relevant potential definitions of a severe epidemic; namely, an outbreak in which: (i) a large number of hosts are infected simultaneously; (ii) a large total number of infections occur; and (iii) the pathogen remains in the population for a long period. We show that the probability of a severe epidemic under these definitions often coincides with the standard branching process estimate for the major epidemic probability. However, these practically relevant risk assessments can also be different from the major epidemic probability, as well as from each other. This holds in different epidemiological systems, highlighting that careful consideration of how to classify a severe epidemic is vital for accurate epidemic risk quantification.
... This, in effect, dilutes the effectiveness of the closures. School children, for example, are known to act as maintenance hosts of influenza, and therefore the rationale for school closure is to reduce contact and subsequent transmission among children and in the social scene within the school setting (Mizumoto, Yamamoto, & Nishiura, 2013;Wu, Cowling, Lau et al., 2010). Table 3 gives a summary of behavioural tendencies that need to be highly discouraged among adults and children. ...
By incorporating emotionality, this paper proposes to enrich cognitive information processing among the general public in times of crisis as evident in COVID-19. Two distinct emotional responses namely fear and anxiety with sufficient enthusiasm profoundly influences our behaviour and responses towards the disease. Fear because the threat of the coronavirus disease is real, and anxiety because of the novelty that stimulates our utmost attention toward COVID-19. The anxiety powerfully influences preferences and stimulates our involvement in the COVID-19 health and wellness campaign. The discussion enhances a phenomenological theoretical perspective concerning cognitive and emotional processes as mutually engaged and in turn supportive as countries and the public adopt various intervention measures aimed at curbing the spread of the COVID-19 pandemic. The discussions demonstrate the cognitive information process and fathoms out how people can appropriately practice emotions as tools towards dealing with the fear and anxiety of COVID-19.
... These estimates were consistent with the relative infection rates of individual types/subtypes. Note, however, due to stringent public health interventions (i.e., case isolation, contact tracing, and school closure) implemented from early May to mid-July 2009 [44] and self-protection (e.g., improved personal hygiene and social distancing) during that time [45], the pandemic in Hong Kong unfolded relatively slowly and estimated population susceptibility at the beginning of the 2009 pandemic was relatively low (~71% in mid-July; Fig 2). The basic reproductive number R 0 was in general higher for A(H3N2) (1.6; range: 1.3-2.0) ...
Influenza epidemics cause substantial morbidity and mortality every year worldwide. Currently, two influenza A subtypes, A(H1N1) and A(H3N2), and type B viruses co-circulate in humans and infection with one type/subtype could provide cross-protection against the others. However, it remains unclear how such ecologic competition via cross-immunity and antigenic mutations that allow immune escape impact influenza epidemic dynamics at the population level. Here we develop a comprehensive model-inference system and apply it to study the evolutionary and epidemiological dynamics of the three influenza types/subtypes in Hong Kong, a city of global public health significance for influenza epidemic and pandemic control. Utilizing long-term influenza surveillance data since 1998, we are able to estimate the strength of cross-immunity between each virus-pairs, the timing and frequency of punctuated changes in population immunity in response to antigenic mutations in influenza viruses, and key epidemiological parameters over the last 20 years including the 2009 pandemic. We find evidence of cross-immunity in all types/subtypes, with strongest cross-immunity from A(H1N1) against A(H3N2). Our results also suggest that A(H3N2) may undergo antigenic mutations in both summers and winters and thus monitoring the virus in both seasons may be important for vaccine development. Overall, our study reveals intricate epidemiological interactions and underscores the importance of simultaneous monitoring of population immunity, incidence rates, and viral genetic and antigenic changes.
... While there is much research on the impact of short-term school closures with regards to the spread of the H1N1 virus (Earn et al. 2012;Lee et al. 2010;Wu et al. 2010) and to financial costs (Effler et al. 2010;Johnson et al. 2008;Sadique et al. 2008), little is known about the social, emotional, and pedagogical impact of extensive school closures for families and teachers, or about the consequences of a gradual return to school with many new safety protocols, along with hybrid options for learning. ...
The government’s rapid response to the spread of Covid-19 in British Columbia has resulted in drastic and unprecedented changes to the delivery of K-12 education. Using qualitative research methods, including remote in-depth interviews, this article addresses the question: What is the educational impact of the Covid-19 rapid response on teachers, students, and families in the Lower Mainland of British Columbia, Canada? Six themes are discussed, including teacher and family responses to change, vulnerability, transitions, work/home life balance, holistic teaching practices and communication. The article ends with recommendations relating to the communication and implementation of health, care, and educational practices that better attend to vulnerable populations and address social emotional wellness.
... When the research was conducted, more than 124 countries around the world, including Indonesia, have closed their schools and universities. Closing schools is one of the effective ways to prevent the spread of the epidemics, in particular, to prevent the virus spread among students (Cauchemez et al., 2009;Cowling et al., 2010;Wu et al., 2010;Jackson et al., 2013). ...
This study investigates the distance learning process of teachers during school closure due to COVID-19's impact. This research focuses on the introduction of distance learning, the obstacles faced by teachers and approaches to addressing different hurdles in the implementation of distance learning. This study collected data from mathematics and science teachers spread in junior and senior high schools in Aceh Province, Indonesia. Data were collected through a questionnaire from 353 teachers and interview from 6 teachers to get in-depth information related to the focus of this study. The results of the study revealed that teachers could not directly utilize various Information and Communication Technology (ICT) devices and online learning platforms that are widely available in supporting distance implementation, either due to the ability of teachers, parents’ economic factors, limited internet access, and the absence of guidance. However, over time, the teacher can independently adapt to environmental conditions and the characteristics of students in carrying out distance learning.
... In 2003, 1755 of the 8096 confirmed SARS cases worldwide (21.7%), were recorded in Hong Kong (WHO, 2003). Various influenza viruses, such as H1N1, H5N1 and H7N9, have spread widely through Hong Kong (Tam, 2002;Wu et al., 2010;Wu et al., 2013). In the COVID-19 pandemic, as of 1 June 2020, Hong Kong had reported 1,093 confirmed cases (HKCHP, 2020a). ...
COVID-19 threatens the world. Social distancing is a significant factor in determining the spread of this disease, and social distancing is strongly affected by the local travel behaviour of people in large cities. In this study, we analysed the changes in the local travel behaviour of various population groups in Hong Kong, between 1 January and 31 March 2020, by using second-by-second smartcard data obtained from the Mass Transit Railway Corporation (MTRC) system. Due to the pandemic, local travel volume decreased by 43%, 49% and 59% during weekdays, Saturdays and Sundays, respectively. The local travel volumes of adults, children, students and senior citizens decreased by 42%, 86%, 73% and 48%, respectively. The local travel behaviour changes for adults and seniors between non-pandemic and pandemic times were greater than those between weekdays and weekends. The opposite was true for children and students. During the pandemic, the daily commute flow decreased by 42%. Local trips to shopping areas, amusement areas and borders decreased by 42%, 81% and 99%, respectively. The effective reproduction number (R
t
) of COVID-19 had the strongest association with daily population use of the MTR 7-8 days earlier.
... Because of the potential social, economic, and healthrelated costs associated with widespread epidemics that affect school-aged children and their families, a substantial body of research has looked at the impact of planned or unplanned school closures on epidemic outcomes (e.g., Fumanelli et al., 2016;Jackson et al., 2013;Markel et al., 2007;Viner et al., 2020;Wu et al., 2010). However, the focus of this article is on scenarios and potential interventions when attendance patterns vary even when schools are open; thus, we do not focus on closures implemented only at the time of an epidemic. ...
Objectives:
Especially in traditional, rural, and low-income areas, children attend school irregularly. School-based interventions are common mitigation strategies for infectious disease epidemics, but if daily attendance is not the norm, the impact of schools on disease spread might be overestimated.
Methods:
We use an agent-based model of an early 20th century Newfoundland community to compare epidemic size and duration in three scenarios: (1) all school-aged children attend school each weekday, (2) students aged 10-15 have a chance of engaging in adult activities each day, and (3) students aged 10-15 have a chance of being reassigned to adult roles at the start of each simulation and thus never attend school.
Results:
As the probability of not attending school increases, epidemics become smaller and peak earlier. The change in final size is larger with permanent reassignment (35% at baseline, 18% at maximum reassignment) than with daily nonattendance (35% vs. 22%). For both scenarios, the peak occurs 3 days earlier with maximum absence compared to the baseline. Benefits extend beyond the reassigned agents, as all school-aged agents are more likely to escape infection with increasing reassignment, and on average, 3-6 additional agents (2.6%-5.3%) escape infection compared to the baseline.
Conclusions:
This study demonstrates that absenteeism can have important impacts on epidemic outcomes. Thus, socioeconomic and other reasons for nonattendance of school, as well as how rates vary in different contexts, must be considered in models predicting epidemic outcomes or evaluating public health interventions in the face of major pandemics.
... S chool closures are one of many non-pharmaceutical interventions that can be employed during epidemics of droplet infections, such as influenza, to reduce transmission, and can be highly effective [1][2][3] . However, there are substantial societal and economic costs associated with closing large numbers of schools, such as limiting children's access to education and requiring caregivers to stay at home (impacting on household income and on economic activity) [4][5][6][7][8] , which can affect more economically deprived households most 9 . ...
In early 2020 many countries closed schools to mitigate the spread of SARS-CoV-2. Since then, governments have sought to relax the closures, engendering a need to understand associated risks. Using address records, we construct a network of schools in England connected through pupils who share households. We evaluate the risk of transmission between schools under different reopening scenarios. We show that whilst reopening select year-groups causes low risk of large-scale transmission, reopening secondary schools could result in outbreaks affecting up to 2.5 million households if unmitigated, highlighting the importance of careful monitoring and within-school infection control to avoid further school closures or other restrictions.
... However, evidence is mixed on the extent to which K-12 school closure slows the spread of coronavirus outbreaks (Viner et al. 2020;Zhang et al. 2020). Influenza transmission is lower when schools are closed for the summer or holidays (Chao, Halloran, and Longini 2010;Chowell et al. 2011;Earn et al. 2012;Huang et al. 2014;Litvinova et al. 2019;Wu et al. 2010) and school closures substantially reduce the number of social contacts among both students and workers (Cauchemez et al. 2008;Huang et al. 2014;Jackson et al. 2011). Reviews find early school closures can slow influenza transmission ideal role of education is far from reality. ...
Mixed evidence on the relationship between school closure and COVID-19 prevalence could reflect focus on large-scale levels of geography, limited ability to address endogeneity, and demographic variation. Using county-level Centers for Disease Control and Prevention (CDC) COVID-19 data through June 15, 2020, two matching strategies address potential heterogeneity: nearest geographic neighbor and propensity scores. Within nearest neighboring pairs in different states with different school closure timing, each additional day from a county’s first case until state-ordered school closure is related to 1.5 to 2.4 percent higher cumulative COVID-19 deaths per capita (1,227–1,972 deaths for a county with median population and deaths/capita). Results are consistent using propensity score matching, COVID-19 data from two alternative sources, and additional sensitivity analyses. School closure is more strongly related to COVID-19 deaths in counties with a high concentration of Black or poor residents, suggesting schools play an unequal role in transmission and earlier school closure is related to fewer lives lost in disadvantaged counties.
... As a result of COVID-19, face to face education was given up. This has been regarded as an effective way for preventing the spread of any epidemic among students Jackson et al., 2013;Wu et al., 2010). ...
COVID-19 has caused profound changes in various dimensions of people’s lives. Education system is one of the areas affected most; and there have been profound changes mainly with regard to teachers, students and parents. The main purpose of this research is to analyse the effects of COVID-19 pandemic on ICT competences and experiences of classroom teachers and parents in various dimensions. Scales were developed to collect data for the research. The reliability of the scale was examined by calculating Cronbach Alpha coefficients; which were .690 and .793 for the Distance Education and Pandemic Scale; respectively. In the second study a total of 1345 people participated in the study, including 841 classroom teachers and 504 parents whose children attending primary schools. The findings of the second study revealed significant differences between teachers and parents. Based on the findings of the current study, following suggestions could be given; both parents and teachers should be informed and educated about ICT usage. Teachers should use digital applications like Web 2.0 tools which will direct them through interactive way of teaching.
... In Mexico, the source country for the H1N1 pandemic, schools closed for 14 days from 27 April to 10 May (Herrera-Valdez et al. 2011). Targeted citylevel closures occurred for three weeks in Bangkok, Thailand (Chieochansin et al. 2009), four days in Auckland, New Zealand (Stuart et al. 2013), and one month in Hong Kong (Wu et al. 2010). Information on school closures during the 1918-1919 influenza ("Spanish flu") pandemic that killed at least 50 million people and infected one third of the global population (CDC n.d.-a) is difficult to find. ...
The COVID-19 pandemic has seen an unprecedented shutdown of society. Among the various safety measures taken, much attention has been given to school closure as a non-pharmaceutical mitigation tool to curb the spread of the disease through ensuring “social” (physical) distancing. Nearly 1.725 billion children in over 95% of countries worldwide have been affected by school closures implemented in April 2020 as the virus continued to spread. In the field of education, policymakers’ attention has been directed at keeping students on board through remote learning and addressing the immediate needs of schools upon reopening. The study presented in this article focuses on who remains absent after schools resume. Using publicly available survey data from the USAID Demographic Health Surveys Program and the UNICEF Multiple Indicator Cluster Survey from before and after the 2013–2016 Ebola pandemic in Guinea and Sierra Leone in West Africa, the author examined changes in school enrolment and dropout patterns, with targeted consideration given to traditionally marginalised groups. At the time, schools closed for between seven to nine months in the two countries; this length and intensity makes this Ebola pandemic the only health crisis in the recent past to come close to the pandemic-related school closures experienced in 2020. The author’s findings suggest that post-Ebola, youth in the poorest households saw the largest increase in school dropout. Exceeding expected pre-Ebola dropout rates, an additional 17,400 of the poorest secondary-age youth were out of school. This evidence is important for minimising the likely post-COVID-19 expansion in inequality. The author’s findings point to the need for sustainable planning that looks beyond the reopening of educational institutions to include comprehensive financial support packages for groups most likely to be affected.
... This paper contributes to the extensive literature that exists on assessing the effectiveness and application of public health policies. Although there are several studies evaluating isolation [1,2], quarantine [3,4], travel restrictions [5][6][7], school closures [8,9], vaccination [10], and other epidemic control measures, most studies applied mathematical modeling, numerical simulation methods or statistical correlation analysis, while econometric approaches for causality analysis are rarely applied to the evaluation of health policies. Since the outbreak of COVID-19, there have been several studies on this virus using econometric methods [11][12][13], which lays a good foundation for our research. ...
We collected COVID-19 epidemiological and epidemic control measures-related data in mainland China during the period January 1 to February 19, 2020, and empirically tested the practical effects of the epidemic control measures implemented in China by applying the econometrics approach. The results show that nationally, both traffic control and social distancing have played an important role in controlling the outbreak of the epidemic, however, neither of the two measures have had a significant effect in low-risk areas. Moreover, the effect of traffic control is more successful than that of social distancing. Both measures complement each other, and their combined effect achieves even better results. These findings confirm the effectiveness of the measures currently in place in China, however, we would like to emphasize that control measures should be more tailored, which implemented according to each specific city’s situation, in order to achieve a better epidemic prevention and control.
... Although there were cases confirmed on or before January 16, the official diagnostic protocol was released by WHO on January 17 (World Health Organization, 2020b). To adjust the impact of this event, we considered a time-varying reporting rate that follows a linear increasing trend, motivated by the previous study (Wu et al., 2010). We assumed that the reporting rate, r(t), started increasing on January 17, and stopped at the maximal level on January 21. ...
Backgrounds:
An ongoing outbreak of a novel coronavirus (2019-nCoV) pneumonia hit a major city of China, Wuhan, December 2019 and subsequently reached other provinces/regions of China and countries. We present estimates of the basic reproduction number,R0, of 2019-nCoV in the early phase of the outbreak.
Methods:
Accounting for the impact of the variations in disease reporting rate, we modelled the epidemic curve of 2019-nCoV cases time series, in mainland China from January 10 to January 24, 2020, through the exponential growth. With the estimated intrinsic growth rate (γ), we estimated R0 by using the serial intervals (SI) of two other well-known coronavirus diseases, MERS and SARS, as approximations for the true unknown SI.
Findings:
The early outbreak data largely follows the exponential growth. We estimated that the meanR0 ranges from 2.24 (95%CI: 1.96-2.55) to 3.58 (95%CI: 2.89-4.39) associated with 8-fold to 2-fold increase in the reporting rate. We demonstrated that changes in reporting rate substantially affect estimates of R0. CONCLUSION: The mean estimate ofR0 for the 2019-nCoV ranges from 2.24 to 3.58, and significantly larger than 1. Our findings indicate the potential of 2019-nCoV to cause outbreaks.
... It is estimated that more than 1,576, 021, 858, which constitute about 91.3% of all the learners across the globe, have been affected by the closure of educational institutions (Fong et al., 2020;Nicola et al., 2020;Sadique Adams & Edmunds, 2008;Brown et al., 2011;UNESCO, 2020). Apart from the impact on learners, school closures have high economic, health and social costs (Cauchemez et al., 2009;Brown et al., 2011;Wu et al., 2010). ...
Education is among the sectors with devastating impact of COVID-19 pandemic. Before the pandemic, the Nigerian education system has adopted purely, face-to-face approached to teaching and learning in primary and secondary schools. Primary and secondary school learners were not allowed to own any digital gadget such as phone or computer, neither were they allowed to be seen with such in the schools. With the emergence of the lockdown condition and school closure, following the COVID-19 pandemic, both teachers and learners were helpless about how to continue learning in the face of the pandemic. This study investigated the challenges posed by, and the impacts of COVID-19 on Education in Nigeria. A sequential exploratory mixed method design was adopted for the study. Results showed that the challenges of education during the COVID-19 pandemic include school closure, poor learning, unequal access to education opportunities and poor skills. Further, the pandemic negatively impacts education, causing poor school enrollment, inequality in education, poor achievement, poor school health and challenges in school assessment and transition. It was concluded that COVID-19 has negatively affected education in Nigeria. Implications for practice policy and practice of electronic learning (e-learning) were discussed.
... Educational outcomes are likely to be a long-term casualty of COVID-19 restrictions. School closures are an expensive but effective way of slowing the peak of a pandemic [38]. However, other measures such as rapid contact tracing and case isolation, surveillance networks and personal protective equipment for healthcare workers are much more cost-efficient [39]. ...
The sobering reality of the COVID-19 pandemic is that it has brought people together at home at a time when we want them apart in the community. This will bring both benefits and challenges. It will affect people differently based upon their age, health status, resilience, family support structures, and socio-economic background. This article will assess the impact in high income countries like Australia, where the initial wave of infection placed the elderly at the greatest risk of death whilst the protective measures of physical distancing, self-isolation, increased awareness of hygiene practices, and school closures with distance learning has had considerable impact on children and families acutely and may have ramifications for years to come.
We review the scientific literature about general-population-lockdown and social-distancing measures, which is relevant to mitigation policy in Canada. Federal and provincial Canadian government responses to and communications about COVID-19 have been irresponsible. The latest research implies that the government interventions to “flatten the curve” risk causing significant additional cumulative COVID-19 deaths, due to seasonal driving of transmissibility and delayed societal immunity. (OCLA Report 2020-1 - Ontario Civil Liberties Association)
Background
The outbreak of novel coronavirus disease (COVID-19), started from Wuhan, China, at the end of December 2019, hits almost the entire world. In Bangladesh, the first case was officially reported on March 8, 2020. We estimated the basic reproductive number, R 0 , of COVID-19 for Bangladesh using the first 65-day data of the outbreak.Methods
With time-varying disease reporting rate, epidemic curves were estimated using the exponential growth model utilizing daily COVID-19 diagnosis data in Bangladesh from March 8 to May 11, 2020. We estimated R 0 using the estimated intrinsic growth rate (γ). Serial intervals (SI) have been used from two well-known coronaviruses’ outbreaks, SARS and MERS; and the early estimate of SI of COVID-19 in Wuhan, China.ResultsThe COVID-19 epidemic in Bangladesh followed an exponential growth model. We found the R 0 to be 1.84 [95% CI: 1.82–1.86], 1.82 [95% CI: 1.81–1.84], and 1.94 [95% CI: 1.92–1.96], for MERS, COVID-19, and SARS SI respectively without adjusting reporting rate. With the adjusted reporting rate, R 0 reduced to 1.63 [95% CI: 1.62–1.65], 1.62 [95% CI: 1.61–1.64], and 1.71 [95% CI: 1.70–1.73] for a five-fold increase. Inverse association between the reporting rate and the basic reproduction number was observed.Conclusion
The R 0 was found to be 1.87 for existing cases and was reduced to 1.65 for the five-fold increase of the early reporting rate. Findings suggest a continued COVID-19 outbreak in Bangladesh and immediate steps need to be taken to control.
Forecasting influenza epidemics has important practical implications. However, the performance of traditional methods adopting in Hong Kong influenza forecasting is limited due to its particularity. This paper proposes an integrated approach for Hong Kong influenza epidemics forecasting. The novelties of our approach mainly include: firstly, we adopt a model for Google search queries data collection and selection in Hong Kong to substitute Google Correlate. Secondly, we adopt the stacked autoencoder (SAE) to reduce the dimensionality of Google search queries data. Thirdly, we adopt a signal decomposition method named variational mode decomposition (VMD) to decompose the influenza data into modes with different frequencies, which can extract the characteristic. Fourthly, we use artificial neural networks (ANN) to forecast these modes of influenza epidemics extracted by VMD respectively, then these forecasts of each mode are added to generate the final forecasting results. From the perspective of forecasting accuracy and hypothesis tests, the empirical results show that our proposed integrated approach SAE-VMD-ANN significantly outperforms some other benchmark models both in the whole period and influenza season. The performance of our proposed model during the COVID-19 pandemic is checked too.
Since COVID-19 was announced in China in December 2019, the pandemic has become a central focus all over the World. Despite the extent of the crisis with initial high death rates in China, Italy and Spain, there exists a wishful fantasy in the low-and middle-income countries that the population will be somehow protected from the extreme anguish and pain. This is even though the more developing countries have tended to have critical problems such as perennial drought, cancer, political instability and war, poverty and ill health, including communicable disease and HIV/AIDS. Although other issues have been placed in the periphery amidst the corona epidemic, there is an obvious need to identify and comprehend in psychological terms various intervention strategies to deal with the pandemic. Besides, some of the similarities in dealing with the pandemic are astonishing. Most of these countries are former colonies and display common patterns aimed at controlling the population using the military forces, including the adoption of curfews and lockdowns. This builds up high levels of intolerable pressure and a depressed attitude, often culminating in stress, fear and anxiety. This paper proposes a comprehensive conceptual approach to this phenomenon and the underlying psychological concerns.
Background:
School closures have been enacted as a measure of mitigation during the ongoing coronavirus disease 2019 (COVID-19) pandemic. It has been shown that school closures could cause absenteeism among healthcare workers with dependent children, but there remains a need for spatially granular analyses of the relationship between school closures and healthcare worker absenteeism to inform local community preparedness.
Methods:
We provide national- and county-level simulations of school closures and unmet child care needs across the USA. We develop individual simulations using county-level demographic and occupational data, and model school closure effectiveness with age-structured compartmental models. We perform multivariate quasi-Poisson ecological regressions to find associations between unmet child care needs and COVID-19 vulnerability factors.
Results:
At the national level, we estimate the projected rate of unmet child care needs for healthcare worker households to range from 7.4 to 8.7%, and the effectiveness of school closures as a 7.6% and 8.4% reduction in fewer hospital and intensive care unit (ICU) beds, respectively, at peak demand when varying across initial reproduction number estimates by state. At the county level, we find substantial variations of projected unmet child care needs and school closure effects, 9.5% (interquartile range (IQR) 8.2-10.9%) of healthcare worker households and 5.2% (IQR 4.1-6.5%) and 6.8% (IQR 4.8-8.8%) reduction in fewer hospital and ICU beds, respectively, at peak demand. We find significant positive associations between estimated levels of unmet child care needs and diabetes prevalence, county rurality, and race (p<0.05). We estimate costs of absenteeism and child care and observe from our models that an estimated 76.3 to 96.8% of counties would find it less expensive to provide child care to all healthcare workers with children than to bear the costs of healthcare worker absenteeism during school closures.
Conclusions:
School closures are projected to reduce peak ICU and hospital demand, but could disrupt healthcare systems through absenteeism, especially in counties that are already particularly vulnerable to COVID-19. Child care subsidies could help circumvent the ostensible trade-off between school closures and healthcare worker absenteeism.
Background:
The province of Ontario, Canada, has instituted indefinite school closures (SC) as well as other social distancing measures to mitigate the impact of the novel coronavirus disease 2019 (COVID-19) pandemic. We sought to evaluate the effect of SC on reducing attack rate and the need for critical care during COVID-19 outbreaks, while considering scenarios with concurrent implementation of self-isolation (SI) of symptomatic cases.
Methods:
We developed an age-structured agent-based simulation model and parameterized it with the demographics of Ontario stratified by age and the latest estimates of COVID-19 epidemiologic characteristics. Disease transmission was simulated within and between different age groups by considering inter- and intra-group contact patterns. The effect of SC of varying durations on the overall attack rate, magnitude and peak time of the outbreak, and requirement for intensive care unit (ICU) admission in the population was estimated. Secondly, the effect of concurrent community-based voluntary SI of symptomatic COVID-19 cases was assessed.
Results:
SC reduced attack rates in the range of 7.2-12.7% when the duration of SC increased from 3 to 16 weeks, when contacts among school children were restricted by 60-80%, and in the absence of SI by mildly symptomatic persons. Depending on the scenario, the overall reduction in ICU admissions attributed to SC throughout the outbreak ranged from 3.3 to 6.7%. When SI of mildly symptomatic persons was included and practiced by 20%, the reduction of attack rate and ICU admissions exceeded 6.3% and 9.1% (on average), respectively, in the corresponding scenarios.
Conclusion:
Our results indicate that SC may have limited impact on reducing the burden of COVID-19 without measures to interrupt the chain of transmission during both pre-symptomatic and symptomatic stages. While highlighting the importance of SI, our findings indicate the need for better understanding of the epidemiologic characteristics of emerging diseases on the effectiveness of social distancing measures.
Background:
Influenza is an acute viral respiratory tract infection caused by influenza virus and transmitted from person to person. Though usually seasonal in temperate climates, influenza occurs throughout the year in the tropics with outbreaks occurring at irregular intervals. On February 6, 2018, a number of students from a Senior High School (SHS) in Accra reported to a district hospital with cough, fever and other respiratory symptoms. An influenza-like illness (ILI) outbreak was suspected. We investigated to determine the magnitude and source of the outbreak and implement control and preventive measures.
Methods:
We interviewed health workers, staff and students of the school as well as case-patients and reviewed health records to collect data on demographic characteristics, signs and symptoms, date of illness onset and outcome. We defined ILI case as "any person in the SHS with fever (measured axillary temperature of ≥ 37.5 °C or history of fever) and cough with or without sore throat or runny nose from January 21 to February 26, 2018". We conducted active case search to identify more cases and took oropharyngeal samples for laboratory testing. We performed descriptive and inferential analysis by calculating attack rate ratios (ARR) and their exact 95% confidence intervals (CI).
Results:
Of the 3160 students, 104 case-patients were recorded from January 25, 2018 to February 13, 2018 (overall attack rate of 3.3%). Mean age of case-patients was 16.1 (±2.3) years with males constituting 71.2% (74/104). Sex specific attack rates were 5.6% (74/1331) and 1.6% (30/1829) for males and females respectively. Compared to females, males were 3.4 times as likely to be ill [ARR =3.4, 95%CI = (2.23-5.15)]. Nine oropharyngeal samples from 17 suspected case-patients tested positive for influenza A (H1N1)pdm09.
Conclusion:
Outbreak of influenza A (H1N1)pdm09 occurred in a SHS in Accra from January to February, 2018. Even though source of the outbreak could not be determined, prompt case management and health education on hand and personal hygiene as non-pharmacological factors probably contributed to the outbreak control. The outbreak ended with a scheduled mid-term break. This underscores the need for more evidence on the effect of school closure in influenza outbreak control.
This chapter provides an overview of infectious disease epidemiology, highlighting some of the major methodological paradigm shifts throughout the development of the field. It reviews the typical descriptive, predictive, and prescriptive paradigms, and at the same time, introduces the needs for a new paradigm to most effectively address the increasingly complex real-world challenges in disease control and prevention.
In light of the current SARS-CoV-2 pandemic, we review the history of past pandemics. We draw on existing literature to characterise historical and contemporary infectious agents by their transmission modes and dynamics and their mortality impact. We then give a concise summary of 20 historical pandemics, their origins, spread and impact. Moreover, we reflect on the semantic shifts which the term pandemic has undergone, discuss the role of human mobility and other factors in the worldwide spread of infectious disease, and outline some historical trends in public-health response to pandemics. Finally, we touch on recent pandemic threats such as SARS, MERS, and Ebola, elaborate on their zoonotic origin, and compile some lessons that were drawn from these outbreaks.
Background
Due to variations in climatic conditions, the effects of meteorological factors and PM2.5 on influenza activity, particularly in subtropical regions, vary in existing literature. In this study, we examined the relationship between influenza activity, meteorological parameters, and PM2.5.
Methods
A total of 20 165 laboratory‐confirmed influenza cases in Hangzhou, Zhejiang province, were documented in our dataset and aggregated into weekly counts for downstream analysis. We employed a combination of the quasi‐Poisson‐generalized additive model and the distributed lag non‐linear model to examine the relationship of interest, controlling for long‐term trends, seasonal trends, and holidays.
Results
A hockey‐stick association was found between absolute humidity and the risk of influenza infections. The overall cumulative adjusted relative risk (ARR) was statistically significant when weekly mean absolute humidity was low (<10 µg/m³) and high (>17.5 µg/m³). A slightly higher ARR was observed when weekly mean temperature reached over 30.5°C. A statistically significantly higher ARR was observed when weekly mean relative humidity dropped below 67%. ARR increased statistically significantly with increasing rainfall. For PM2.5, the ARR was marginally statistically insignificant. In brief, high temperature, wet and dry conditions, and heavy rainfall were the major risk factors associated with a higher risk of influenza infections.
Conclusions
The present study contributes additional knowledge to the understanding of the effects of various environmental factors on influenza activities. Our findings shall be useful and important for the development of influenza surveillance and early warning systems.
Building an effective and highly usable epidemiology model presents two main challenges: finding the appropriate, realistic enough model that takes into account complex biological, social and environmental parameters and efficiently estimating the parameter values with which the model can accurately match the available outbreak data, provide useful projections. The reproduction number of the novel coronavirus (SARS-CoV-2) has been found to vary over time, potentially being influenced by a multitude of factors such as varying control strategies, changes in public awareness and reaction or, as a recent study suggests, sensitivity to temperature or humidity changes. To take into consideration these constantly evolving factors, the paper introduces a time dynamic, humidity-dependent SEIR-type extended epidemiological model with range-defined parameters. Using primarily the historical data of the outbreak from Northern and Southern Italy and with the help of stochastic global optimization algorithms, we are able to determine a model parameter estimation that provides a high-quality fit to the data. The time-dependent contact rate showed a quick drop to a value slightly below 2. Applying the model for the COVID-19 outbreak in the northern region of Italy, we obtained parameters that suggest a slower shrinkage of the contact rate to a value slightly above 4. These findings indicate that model fitting and validation, even on a limited amount of available data, can provide useful insights and projections, uncover aspects that upon improvement might help mitigate the disease spreading.
In this paper we utilize a combination of national microdata from the Integrated Public Use Microdata Series (IPUMS) with local population and health microdata, spatialized to the household level, and employ an historical GIS (HGIS) to follow infectious disease transmission between public school children in Michigan’s Upper Peninsula during the 1918 influenza pandemic. Microdata are data at the finest, non-aggregated level of precision. We illustrate three important advantages of using historical microdata within an HGIS framework: contextualization of data within their period-accurate space—time, avoidance of the ecological fallacy, and the ability to move freely between micro and macro scales. We demonstrate the potential for studying historic pandemics using historical microdata by doing a spatiotemporal analysis following infectious respiratory disease through three schools from April to June 1918.
The present study investigated the (i) socio-demographic predictors of psychological distress, (ii) socio-demographic predictors of satisfaction from online classes, and (iii) the relationship between psychological distress and satisfaction from online classes among university students of Pakistan during the COVID-19 pandemic. An online questionnaire-based survey was conducted. A total of 2220 respondents that was enrolled at the University of the Punjab (PU), University of Management and Technology (UMT), and the University of Central Punjab (UCP) were involved in the current study. Data were collected at a 64% response rate and analyzed with SPSS IBM Version 21.0. Results revealed that approximately 41% of the students were facing severe psychological distress while about 65% were found unsatisfied with online classes. Besides, a linear negative relationship between the independent variable, i.e. psychological distress and the dependent variable, i.e. satisfaction from online classes was found. Therefore, to minimize the level of psychological distress and increase students’ satisfaction with online classes it is highly recommended to take precautionary measures by the relevant stakeholders.
The humans’ vulnerability and fragility have been demonstrated during pandemics, and as a community, will need proper preparation. The coronavirus outbreak was first reported at the end of 2019 and declared a pandemic by the World Health Organization. Around the world, the response to the virus outbreak has been different.
The detection, traceability, and the response for different countries have been delayed, causing the overwhelming of the health systems. However, some other nations exercised various strategies to contain the infection’s dissemination and recorded a low number of cases. The different measures taken, including contact tracing, lockdown, case detection, social distancing, and quarantine strategies, helped control the disease’s spreading.
Only time will tell how well the world faced the outbreak. We also suggest the future directions that the global community should take to manage and mitigate the emergency.
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.
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.
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.
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.
In the spring of 2009, an outbreak of severe pneumonia was reported in conjunction with the concurrent isolation of a novel swine-origin influenza A (H1N1) virus (S-OIV), widely known as swine flu, in Mexico. Influenza A (H1N1) subtype viruses have rarely predominated since the 1957 pandemic. The analysis of epidemic pneumonia in the absence of routine diagnostic tests can provide information about risk factors for severe disease from this virus and prospects for its control.
From March 24 to April 29, 2009, a total of 2155 cases of severe pneumonia, involving 821 hospitalizations and 100 deaths, were reported to the Mexican Ministry of Health. During this period, of the 8817 nasopharyngeal specimens that were submitted to the National Epidemiological Reference Laboratory, 2582 were positive for S-OIV. We compared the age distribution of patients who were reported to have severe pneumonia with that during recent influenza epidemics to document an age shift in rates of death and illness.
During the study period, 87% of deaths and 71% of cases of severe pneumonia involved patients between the ages of 5 and 59 years, as compared with average rates of 17% and 32%, respectively, in that age group during the referent periods. Features of this epidemic were similar to those of past influenza pandemics in that circulation of the new influenza virus was associated with an off-season wave of disease affecting a younger population.
During the early phase of this influenza pandemic, there was a sudden increase in the rate of severe pneumonia and a shift in the age distribution of patients with such illness, which was reminiscent of past pandemics and suggested relative protection for persons who were exposed to H1N1 strains during childhood before the 1957 pandemic. If resources or vaccine supplies are limited, these findings suggest a rationale for focusing prevention efforts on younger populations.
A novel influenza A (H1N1) virus has spread rapidly across the globe. Judging its pandemic potential is difficult with limited data, but nevertheless essential to inform appropriate health responses. By analyzing the outbreak in Mexico, early data on international spread, and viral genetic diversity, we make an early assessment of transmissibility and severity. Our estimates suggest that 23,000 (range 6000 to 32,000) individuals had been infected in Mexico by late April, giving an estimated case fatality ratio (CFR) of 0.4% (range: 0.3 to 1.8%) based on confirmed and suspected deaths reported to that time. In a community outbreak in the small community of La Gloria, Veracruz, no deaths were attributed to infection, giving an upper 95% bound on CFR of 0.6%. Thus, although substantial uncertainty remains, clinical severity appears less than that seen in the 1918 influenza pandemic but comparable with that seen in the 1957 pandemic. Clinical attack rates in children in La Gloria were twice that in adults (<15 years of age: 61%; >/=15 years: 29%). Three different epidemiological analyses gave basic reproduction number (R0) estimates in the range of 1.4 to 1.6, whereas a genetic analysis gave a central estimate of 1.2. This range of values is consistent with 14 to 73 generations of human-to-human transmission having occurred in Mexico to late April. Transmissibility is therefore substantially higher than that of seasonal flu, and comparable with lower estimates of R0 obtained from previous influenza pandemics.
The World Health Organization's recommended pandemic influenza interventions, based on limited data, vary by transmission pattern, pandemic phase, and illness severity and extent. In the pandemic alert period, recommendations include isolation of patients and quarantine of contacts, accompanied by antiviral therapy. During the pandemic period, the focus shifts to delaying spread and reducing effects through population-based measures. Ill persons should remain home when they first become symptomatic, but forced isolation and quarantine are ineffective and impractical. If the pandemic is severe, social distancing measures such as school closures should be considered. Nonessential domestic travel to affected areas should be deferred. Hand and respiratory hygiene should be routine; mask use should be based on setting and risk, and contaminated household surfaces should be disinfected. Additional research and field assessments during pandemics are essential to update recommendations. Legal authority and procedures for implementing interventions should be understood in advance and should respect cultural differences and human rights.
A variety of Serfling-type statistical algorithms requiring long series of historical data, exclusively from temperate climate zones, have been proposed for automated monitoring of influenza sentinel surveillance data. We evaluated three alternative statistical approaches where alert thresholds are based on recent data in both temperate and subtropical regions.
We compared time series, regression, and cumulative sum (CUSUM) models on empirical data from Hong Kong and the US using a composite index (range = 0-1) consisting of the key outcomes of sensitivity, specificity, and time to detection (lag). The index was calculated based on alarms generated within the first 2 or 4 weeks of the peak season.
We found that the time series model was optimal in the Hong Kong setting, while both the time series and CUSUM models worked equally well on US data. For alarms generated within the first 2 weeks (4 weeks) of the peak season in Hong Kong, the maximum values of the index were: time series 0.77 (0.86); regression 0.75 (0.82); CUSUM 0.56 (0.75). In the US data the maximum values of the index were: time series 0.81 (0.95); regression 0.81 (0.91); CUSUM 0.90 (0.94).
Automated influenza surveillance methods based on short-term data, including time series and CUSUM models, can generate sensitive, specific, and timely alerts, and can offer a useful alternative to Serfling-like methods that rely on long-term, historically based thresholds.
The threat posed by the highly pathogenic H5N1 influenza virus requires public health authorities to prepare for a human pandemic. Although pre-pandemic vaccines and antiviral drugs might significantly reduce illness rates, their stockpiling is too expensive to be practical for many countries. Consequently, alternative control strategies, based on non-pharmaceutical interventions, are a potentially attractive policy option. School closure is the measure most often considered. The high social and economic costs of closing schools for months make it an expensive and therefore controversial policy, and the current absence of quantitative data on the role of schools during influenza epidemics means there is little consensus on the probable effectiveness of school closure in reducing the impact of a pandemic. Here, from the joint analysis of surveillance data and holiday timing in France, we quantify the role of schools in influenza epidemics and predict the effect of school closure during a pandemic. We show that holidays lead to a 20-29% reduction in the rate at which influenza is transmitted to children, but that they have no detectable effect on the contact patterns of adults. Holidays prevent 16-18% of seasonal influenza cases (18-21% in children). By extrapolation, we find that prolonged school closure during a pandemic might reduce the cumulative number of cases by 13-17% (18-23% in children) and peak attack rates by up to 39-45% (47-52% in children). The impact of school closure would be reduced if it proved difficult to maintain low contact rates among children for a prolonged period.
The World Health Organization's recommended pan- demic influenza interventions, based on limited data, vary by transmission pattern, pandemic phase, and illness severity and extent. In the pandemic alert period, recom- mendations include isolation of patients and quarantine of contacts, accompanied by antiviral therapy. During the pan- demic period, the focus shifts to delaying spread and reducing effects through population-based measures. Ill persons should remain home when they first became symptomatic, but forced isolation and quarantine are inef- fective and impractical. If the pandemic is severe, social distancing measures such as school closures should be considered. Nonessential domestic travel to affected areas should be deferred. Hand and respiratory hygiene should be routine; mask use should be based on setting and risk, and contaminated household surfaces should be disinfec- ted. Additional research and field assessments during pan- demics are essential to update recommendations. Legal authority and procedures for implementing interventions should be understood in advance and should respect cul- tural differences and human rights.
In response to WHO raising the influenza pandemic alert level from phase five to phase six, health officials around the world are carefully reviewing pandemic mitigation protocols. School closure (also called class dismissal in North America) is a non-pharmaceutical intervention that is commonly suggested for mitigating influenza pandemics. Health officials taking the decision to close schools must weigh the potential health benefits of reducing transmission and thus case numbers against high economic and social costs, difficult ethical issues, and the possible disruption of key services such as health care. Also, if schools are expected to close as a deliberate policy option, or just because of high levels of staff absenteeism, it is important to plan to mitigate the negative features of closure. In this context, there is still debate about if, when, and how school closure policy should be used. In this Review, we take a multidisciplinary and holistic perspective and review the multiple aspects of school closure as a public health policy. Implications for the mitigation of the swine-origin influenza A H1N1 pandemic are also discussed.
To determine appropriate influenza pandemic containment and mitigation measures, health authorities need to know the approximate case fatality ratio (CFR) for this new infection. We present four different methods for very provisionally estimating the plausible range of the CFR for symptomatic infection by this pandemic strain in developed countries. All of the methods produce substantially lower values (range 0.06% to 0.0004%) than a previously published estimate for Mexico (0.4%). As these results have many limitations, improved surveillance and serological surveys are needed in both developed and developing countries to produce more accurate estimates.
Many countries plan to close schools during a future influenza pandemic, although the potential impact is poorly understood. We apply a model of the transmission dynamics of pandemic influenza to consultation, serological and clinical data from the United Kingdom from the 1957 (Asian) influenza pandemic, to estimate the basic reproduction number (R0), the proportion of infected individuals who experience clinical symptoms and the impact of school/nursery closures. The R0 for Asian influenza was about 1.8 and 60-65% of infected individuals were estimated to have experienced clinical symptoms. During a future pandemic, closure of schools/nurseries could reduce the epidemic size only by a very small amount (<10%) if R0 is high (e.g. 2.5 or 3.5), and modest reductions, e.g. 22% might be possible if it is low (1.8) and schools are closed early, depending on assumptions about contact patterns. Further data on contact patterns and their dependence on school closures are needed.
A critical question in pandemic influenza planning is the role nonpharmaceutical interventions might play in delaying the temporal effects of a pandemic, reducing the overall and peak attack rate, and reducing the number of cumulative deaths. Such measures could potentially provide valuable time for pandemic-strain vaccine and antiviral medication production and distribution. Optimally, appropriate implementation of nonpharmaceutical interventions would decrease the burden on health care services and critical infrastructure.
To examine the implementation of nonpharmaceutical interventions for epidemic mitigation in 43 cities in the continental United States from September 8, 1918, through February 22, 1919, and to determine whether city-to-city variation in mortality was associated with the timing, duration, and combination of nonpharmaceutical interventions; altered population susceptibility associated with prior pandemic waves; age and sex distribution; and population size and density.
Historical archival research, and statistical and epidemiological analyses. Nonpharmaceutical interventions were grouped into 3 major categories: school closure; cancellation of public gatherings; and isolation and quarantine.
Weekly excess death rate (EDR); time from the activation of nonpharmaceutical interventions to the first peak EDR; the first peak weekly EDR; and cumulative EDR during the entire 24-week study period.
There were 115,340 excess pneumonia and influenza deaths (EDR, 500/100,000 population) in the 43 cities during the 24 weeks analyzed. Every city adopted at least 1 of the 3 major categories of nonpharmaceutical interventions. School closure and public gathering bans activated concurrently represented the most common combination implemented in 34 cities (79%); this combination had a median duration of 4 weeks (range, 1-10 weeks) and was significantly associated with reductions in weekly EDR. The cities that implemented nonpharmaceutical interventions earlier had greater delays in reaching peak mortality (Spearman r = -0.74, P < .001), lower peak mortality rates (Spearman r = 0.31, P = .02), and lower total mortality (Spearman r = 0.37, P = .008). There was a statistically significant association between increased duration of nonpharmaceutical interventions and a reduced total mortality burden (Spearman r = -0.39, P = .005).
These findings demonstrate a strong association between early, sustained, and layered application of nonpharmaceutical interventions and mitigating the consequences of the 1918-1919 influenza pandemic in the United States. In planning for future severe influenza pandemics, nonpharmaceutical interventions should be considered for inclusion as companion measures to developing effective vaccines and medications for prophylaxis and treatment.
Emerging infections: pandemic infl uenza Severe respiratory disease concurrent with the circulation of H1N1 infl uenza
- Wp Glezen
- G Chowell
- Sm Bertozzi
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- C Alpuche-Aranda
- M Hernandez
Glezen WP. Emerging infections: pandemic infl uenza. Epidemiol Rev. 1996;18:64–76. 6. Chowell G, Bertozzi SM, Colchero MA, Lopez-Gatell H, Alpuche-Aranda C, Hernandez M, et al. Severe respiratory disease concurrent with the circulation of H1N1 infl uenza. N Engl J Med. 2009;13;361:674-9.
2009 pandemic infl uenza A (H1N1) virus infections—Chicago, Illinois
- Disease Centers
- Control
- Prevention
Centers for Disease Control and Prevention. 2009 pandemic infl uenza A (H1N1) virus infections—Chicago, Illinois, April–July 2009. MMWR Morb Mortal Wkly Rep. 2009;58:913–8.
School of Public Health The University of Hong Kong, Units 624-7, Cyberport 3, Pokfulam, Hong Kong Special Administrative Region, People's Republic of China; email: bcowling@hku.hk Emerging Infectious Diseases @BULLET www.cdc.gov/eid @BULLET
- Address
- J Benjamin
- Cowling
Address for correspondence: Benjamin J. Cowling, School of Public
Health, The University of Hong Kong, Units 624-7, Cyberport 3,
Pokfulam, Hong Kong Special Administrative Region, People's Republic
of China; email: bcowling@hku.hk
Emerging Infectious Diseases @BULLET www.cdc.gov/eid @BULLET Vol. 16, No. 3, March 2010
2009 pandemic influenza A (H1N1) virus infections—Chicago, Illinois, April–July 2009.
- Centers for Disease Control and Prevention