Europe's initial experience with pandemic (H1N1) 2009 - mitigation and delaying policies and practices

Effects of strict containment policies on COVID-19 pandemic crisis: lessons to cope with next pandemic impacts

The goal of the study here is to analyze and assess whether strict containment policies to cope with Coronavirus Disease 2019 (COVID-19) pandemic crisis are effective interventions to reduce high numbers of infections and deaths. A homogenous sample of 31 countries is categorized in two sets: countries with high or low strictness of public policy to cope with COVID-19 pandemic crisis. The findings here suggest that countries with a low intensity of strictness have average confirmed cases and fatality rates related to COVID-19 lower than countries with high strictness in containment policies (confirmed cases are 24.69% vs. 26.06% and fatality rates are 74.33% vs. 76.38%, respectively, in countries with low and high strictness of COVID-19 public policies of containment). What this study adds is that high levels of strict restriction policies may not be useful measures of control in containing the spread and negative impact of pandemics similar to COVID-19 and additionally a high strictness in containment policies generates substantial social and economic costs. These findings can be explained with manifold socioeconomic and environmental factors that support transmission dynamics and circulation of COVID-19 pandemic. Hence, high levels of strictness in public policy (and also a high share of administering new vaccines) seem to have low effectiveness to stop pandemics similar to COVID-19 driven by mutant viral agents. These results here suggest that the design of effective health policies for prevention and preparedness of future pandemics should be underpinned in a good governance of countries and adoption of new technology, rather than strict and generalized health polices having ambiguous effects of containment in society.

Core policies disparity response to COVID-19 among BRICS countries

Objective

To provide experience for formulating prevention and control policies, this study analyzed the effectiveness of the Coronavirus disease 2019(COVID-19) prevention and control policies, and evaluated health equity and epidemic cooperation among BRICS countries.

Methods

This study summarized the pandemic prevention and control policies in BRICS countries and evaluated the effectiveness of those policies by extracting COVID-19 related data from official websites.

Result

As of May 4, 2021, responding to COVID-19. China adopted containment strategies. China’s total confirmed cases (102,560) were stable, without a second pandemic peak, and the total deaths per million (3.37) were much lower than others. India and South Africa who adopted intermediate strategies have similar pandemic curves, total confirmed cases in India (20,664,979) surpassed South Africa (1,586,148) as the highest in five countries, but total deaths per million (163.90) lower than South Africa (919.11). Brazil and Russia adopted mitigation strategies. Total confirmed cases in Brazil (14,856,888) and Russia (4,784,497) continued to increase, and Brazil’s total deaths per million (1,936.34) is higher than Russia (751.50) and other countries.

Conclusion

This study shows BRICS countries implemented different epidemic interventions. Containment strategy is more effective than intermediate strategy and mitigation strategy in limiting the spread of COVID-19. Especially when a strict containment strategy is implemented in an early stage, but premature relaxation of restrictions may lead to rebounding. It is a good choice to combat COVID-19 by improving the inclusiveness of intervention policies, deepening BRICS epidemic cooperation, and increasing health equities.

Infection surveillance measures during the COVID-19 pandemic in Germany

Introduction: To address the question as to which infection surveillance measures are used during the ongoing COVID-19 pandemic in Germany and how they differ from pre-existing approaches. Methods: In accordance with the systematic approach of a scoping review, a literature search was conducted in national and international medical literature databases using a search string. The search in the databases was limited to the period from 01.01.2000 to 15.11.2020 and has been subsequently completed by hand search until 08.03.2021. A hand search, even beyond 15.11.2020, seemed necessary and reasonable, since due to the dynamics of the ongoing COVID-19 pandemic, a large number of articles and regulations are being published very quickly at short notice. Results: The literature search resulted in the following number of hits in the databases listed below: PubMed: 165 articlesCochrane: 1 review and 35 studiesWeb of Science: 217 articlesRobert Koch Institute: 49 articles Thus, a total of 467 hits were identified, with a total of 124 hits being duplicates. From these, 138 articles were considered relevant to the COVID-19 infection surveillance situation in Germany based on established criteria. After reading the full texts, 92 articles and websites were ultimately included in the scoping review. Discussion: Many of the lessons learned from previous outbreaks seem to have been implemented in the infection surveillance measures during the ongoing COVID-19 pandemic in Germany. Most of the changes compared with previous measures were based on technological streamlining of existing procedures and changes and more inclusion of the population in different infection surveillance measures.

The relation between length of lockdown, numbers of infected people and deaths of Covid-19, and economic growth of countries: Lessons learned to cope with future pandemics similar to Covid-19 and to constrain the deterioration of economic system

How is the relation between duration of lockdown and numbers of infected people and deaths of Coronavirus disease 2019 (COVID-19), and growth level of Gross Domestic Product (GDP) in countries? Results here suggest that, during the first wave of COVID-19 pandemic, countries with a shorter period of lockdown (about 15 days: Austria, Portugal and Sweden) have average confirmed cases divided by population higher than countries with a longer period of lockdown (about 60 days, i.e., 2 months: France, Italy and Spain); moreover, countries with a shorter period of lockdown have average fatality rate (5.45%) lower than countries with a longer length of lockdown (12.70%), whereas average variation of fatality rate from March to August 2020 (first pandemic wave of COVID-19) suggests a higher reduction in countries with a longer period of lockdown than countries with a shorter duration (−1.9% vs. −0.72%). Independent Samples Test reveals that average fatality rate of countries with a shorter period of lockdown was significantly lower than countries with a longer period of lockdown (5.4% vs. 12.7%, p-value<.05). The Mann-Whitney Test confirms that average fatality rate of countries with a shorter period of lockdown is significantly lower than countries having a longer period of lockdown (U = 0, p-value = .005). In addition, results show that lockdowns of longer duration have generated negative effects on GDP growth: average contraction of GDP (index 2010 = 100) from second quarter 2019 to second quarter of 2020 in countries applying a longer period of lockdown (i.e., about two months) is about −21%, whereas it is −13% in countries applying a shorter period of lockdown of about 15 days (significant difference with Independent Samples Test: t₄ = −2.274, p-value < .085). This finding shows a systematic deterioration of economic system because of containment policies based on a longer duration of lockdown in society. Another novel finding here reveals that countries with higher investments in healthcare (as percentage of GDP) have alleviated fatality rate of COVID-19 and simultaneously have applied a shorter period of lockdown, reducing negative effects on economic system in terms of contraction of economic growth. Overall, then, using lessons learned of the first wave of COVID-19 pandemic crisis, this study must conclude that a strategy to reduce the negative impact of future epidemics similar to COVID-19 has to be based on a reinforcement of healthcare sector to have efficient health organizations to cope with pandemics of new viral agents by minimizing fatality rates; finally, high investments in health sector create the social conditions to apply lockdowns of short run with lower negative effects on socioeconomic systems.

Pandemic Prevention: Lessons from COVID-19

Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which appeared in late 2019, generating a pandemic crisis with high numbers of COVID-19-related infected individuals and deaths in manifold countries worldwide. Lessons learned from COVID-19 can be used to prevent pandemic threats by designing strategies to support different policy responses, not limited to the health system, directed to reduce the risks of the emergence of novel viral agents, the diffusion of infectious diseases and negative impact in society.

How do low wind speeds and high levels of air pollution support the spread of COVID-19?

The pandemic of coronavirus disease 2019 (COVID-19) is generating a high number of infected individuals and deaths. One of the current questions is how climatological factors and environmental pollution can affect the diffusion of COVID-19 in human society. This study endeavours to explain the relation between wind speed, air pollution and the diffusion of COVID-19 to provide insights to constrain and/or prevent future pandemics and epidemics. The statistical analysis here focuses on case study of Italy and reveals two main findings: 1) cities with high wind speed have lower numbers of COVID-19 related infected individuals; 2) cities located in hinterland zones (mostly those bordering large urban conurbations) with little wind speed and frequently high levels of air pollution had higher numbers of COVID-19 related infected individuals. Results here suggest that high concentrations of air pollutants, associated with low wind speeds, may promote a longer permanence of viral particles in polluted air of cities, thus favouring an indirect means of diffusion of the novel coronavirus (SARS-CoV-2), in addition to the direct diffusion with human-to-human transmission dynamics.

An index to quantify environmental risk of exposure to future epidemics of the COVID-19 and similar viral agents: Theory and practice

In the presence of the novel Coronavirus Disease (COVID-19) and other new viral agents, one of the fundamental problems in science is the evaluation of environmental and social weaknesses of cities/regions to the exposure of infectious diseases for preventing and/or containing new COVID-19 outbreaks and the diffusion of other viral agents that generate a negative impact on public health and economy of countries. The current monitoring of transmission dynamics of infectious diseases is mainly based on reproduction number (R₀) and fatality rates. However, this approach is a real-time monitoring of transmission dynamics for mitigating the numbers of COVID-19 related infected individuals and deaths. Reproduction number does not provide information to cope with future epidemics or pandemics. The main goal of this study is to propose the Index c (as contagions) that quantifies, ex-ante, the environmental risk of exposure of cities/regions to future epidemics of the COVID-19 and similar vital agents. This Index c synthetizes environmental, demographic, climatological and health risk factors of cities/regions that indicate their exposure to infectious diseases. Index c has a range from 1 (environmental and social weakness of urban areas leading to high levels of exposure to infectious diseases) to 0 (environment that reduces the risk of exposure to infectious diseases in society). The statistical evidence here, applied on case study of Italy, seems in general to support the predictive capacity of the Index c as a particularly simple but superior indicator in detecting the global correlation between potential risk of exposure of cities/regions to infectious diseases and actual risk given by infected individuals and deaths of the COVID-19. The Index c can support a proactive environmental strategy to help policymakers to prevent future pandemics similar to the COVID-19.

THE IMPACT OF LOCKDOWN ON PUBLIC HEALTH DURING THE FIRST WAVE OF COVID-19 PANDEMIC: LESSONS LEARNED FOR DESIGNING EFFECTIVE CONTAINMENT MEASURES TO COPE WITH SECOND WAVE.. [DOI: 10.1101/2020.10.22.20217695]

What is hardly known in the studies of the COVID-19 global pandemic crisis is the impact of general lockdown during the first wave of COVID-19 pandemic both public health and economic system. The main goal of this study is a comparative analysis of some European countries with a longer and shorter period of national lockdown during the first wave of COVID-19 from March to August 2020. Findings suggests that: a) countries with shorter period of lockdown have a variation of confirmed cases/population (%) higher than countries with longer period of lockdown; b) countries with shorter period of lockdown have average fatality rate (5.45%) lower than countries with longer period of lockdown (12.70%), whereas variation of fatality rate from August to March 2020 suggests a higher reduction in countries with longer period of lockdown (−1.9% vs 0.72%). However, Independent Samples Test and the Mann-Whitney test reveal that the effectiveness of longer period of lockdown versus shorter one on public health is not significant. In addition, the COVID-19 pandemic associated with longer period of lockdown has a higher negative impact on economic growth with consequential social issues in countries. Results of the impact of COVID-19 lockdowns on public health and economies of some leading countries in Europe, during the first wave of the COVID-19 pandemic, can provide vital information to design effective containment strategies in future waves of this pandemic to minimize the negative effects in society.

Searching for Digital Technologies in Containment and Mitigation Strategies: Experience from South Korea COVID-19

Background:

Korea has achieved health policy objectives in pandemic management so far, namely minimizing mortality, flattening the epidemic curve, and limiting the socio-economic burden of its measures. The key to the Korean government’s success in combating COVID-19 lies with the latest digital technologies (DTs). The prompt and effective application of DTs facilitates both containment as well as mitigation strategies and their sub-policy measures.

Methods:

This article uses an experiential analysis based on an exploratory case study – analysis on field applications of the government’s interventions. Information is collected by qualitative methods such as literature analysis, meeting materials, and a review of various government reports (including internal ones) along with academic and professional experiences of the authors.

Findings:

The article presents the unique Korean health policy approaches in the COVID-19 crisis. First, DTs allow the Korean government to embrace various policy measures together listed in containment strategy, namely altering and warning, epidemiological investigation, quarantine of contacts, case-finding, social distancing, and mask-wearing. Second, DTs allow Korea to integrate containment and mitigation strategies simultaneously. Along with the above measures in containment, healthcare service, medical treatment, and prophylaxis (presymptomatic testing) within mitigation are utilized to prevent a COVID-19 spread.

Conclusions:

Korea develops DTs in an integrated manner in the early pandemic stage under strong and coordinated government leadership. Above all, the DTs’ functions in each pandemic developmental stage are continuously upgraded. Instead of prioritizing policy measures or strategies, therefore, Korea can implement diverse policies simultaneously by integrating DTs effectively. During the COVID-19 outbreak, DTs work as the enablers to connect these two strategies and their measures in Korea.

Recommendations:

DTs should be at the center of the disaster management paradigm, especially during a pandemic. DTs are facilitators and integrators of containing and mitigating strategies and their policy measures.

Detecting a Surprisingly Low Transmission Distance in the Early Phase of the 2009 Influenza Pandemic

The spread of the 2009 H1N1 influenza pandemic in England was characterized by two major waves of infections: the first one was highly spatially localized (mainly in the London area), while the second one spread homogeneously through the entire country. The reasons behind this complex spatiotemporal dynamics have yet to be clarified. In this study, we perform a Bayesian analysis of five models entailing different hypotheses on the possible determinants of the observed pattern. We find a consensus among all models in showing a surprisingly low transmission distance (defined as the geographic distance between the place of residence of the infectors and her/his infectees) during the first wave: about 1.5 km (2.2 km if infections linked to household and school transmission are excluded). The best-fitting model entails a change in human activity regarding contacts not related to household and school. By using this model we estimate that the transmission distance sharply increased to 5.3 km (10 km when excluding infections linked to household and school transmission) during the second wave. Our study reveals a possible explanation for the observed pattern and highlights the need of better understanding human mobility and activity patterns under the pressure posed by a pandemic threat.

Measuring the effect of influenza A(H1N1)pdm09: the epidemiological experience in the West Midlands, England during the 'containment' phase

The West Midlands was the first English region to report sustained community transmission during the 'containment' phase of the influenza A(H1N1)pdm09 pandemic in England. To describe the epidemiological experience in the region, West Midlands and national datasets containing laboratory-confirmed A(H1N1)pdm09 virus cases in the region during the 'containment' phase were analysed. The region accounts for about 10·5% of England's population, but reported about 42% of all laboratory-confirmed cases. Altogether 3063 cases were reported, with an incidence rate of 56/100 000 population. School-associated cases accounted for 25% of cases. Those aged <20 years, South Asian ethnic groups, and residents of urban and socioeconomically deprived areas were disproportionately affected. Imported cases accounted for 1% of known exposures. Regional R 0 central estimates between 1·41 and 1·43 were obtained. The West Midlands experience suggests that interpretation of transmission rates may be affected by complex interactions within and between sub-populations in the region.

Immunopathogenesis of 2009 pandemic influenza

Three years after the pandemic, major advances have been made in our understanding of the innate and adaptive immune responses to the influenza A(H1N1)pdm09 virus and those responses' contribution to the immunopathology associated with this infection. Severe disease is characterized by early secretion of proinflammatory and immunomodulatory cytokines. This cytokine secretion persisted in patients with severe viral pneumonia and was directly associated with the degree of viral replication in the respiratory tract. Cytokines play important roles in the antiviral defense, but persistent hypercytokinemia may cause inflammatory tissue damage and participate in the genesis of the respiratory failure observed in these patients. An absence of pre-existing protective antibodies was the rule for both mild and severe cases. A role for pathogenic immunocomplexes has been proposed for this disease. Defective T cell responses characterize severe cases of infection caused by the influenza A(H1N1)pdm09 virus. Immune alterations associated with accompanying conditions such as obesity, pregnancy or chronic obstructive pulmonary disease may interfere with the normal development of the specific response to the virus. The role of host immunogenetic factors associated with disease severity is also discussed in this review. In conclusion, currently available information suggests a complex immunological dysfunction/alteration that characterizes the severe cases of 2009 pandemic influenza. The potential benefits of prophylactic/therapeutic interventions aimed at preventing/correcting such dysfunction warrant investigation.

Challenges and lessons learned from implementing a risk-based approach to school advice and closure during the containment phase of the 2009 influenza pandemic in the West Midlands, England

OBJECTIVE

School closure as a social distancing measure was used in some countries during the initial phases of the influenza A(H1N1)pdm09 pandemic. The objective of this paper is to describe the use of a risk-based approach to public health interventions for schools during the 'containment phase' of the pandemic and to describe lessons learnt.

METHODS

The development of a framework for risk assessment and decision-making to determine school closures in the West Midlands, England, during the 'containment phase' of influenza A(H1N1)pdm09 pandemic is described.

RESULTS

Using the framework developed during the 'containment phase', assessments were conducted for 344 educational institutions who reported confirmed cases or 'particularly high absenteeism'. Of these, 209 (60%) had confirmed cases and 65 were closed, mainly for public health or operational reasons. Schools were closed on an individual basis, during the most intense period of the pandemic and for an average period of six days (maximum 11 days). The risk-based approach evolved as experience and knowledge of influenza A(H1N1)pdm09 pandemic virus increased, however some decisions were difficult to communicate to parents, schools and stakeholders particularly when the number of schools affected escalated and the pandemic response phases changed.

CONCLUSION

The management of school closures is an 'uncertain art'. Numerous challenges and lessons were identified in attempting, during the containment phase of the influenza A(H1N1)pdm09 pandemic, to ensure consistency and transparency in an increasingly complex process. The overall approach described could be further developed to improve decision-making for infectious diseases in schools.

Economic analysis of pandemic influenza mitigation strategies for five pandemic severity categories

BACKGROUND

The threat of emergence of a human-to-human transmissible strain of highly pathogenic influenza A(H5N1) is very real, and is reinforced by recent results showing that genetically modified A(H5N1) may be readily transmitted between ferrets. Public health authorities are hesitant in introducing social distancing interventions due to societal disruption and productivity losses. This study estimates the effectiveness and total cost (from a societal perspective, with a lifespan time horizon) of a comprehensive range of social distancing and antiviral drug strategies, under a range of pandemic severity categories.

METHODS

An economic analysis was conducted using a simulation model of a community of ~30,000 in Australia. Data from the 2009 pandemic was used to derive relationships between the Case Fatality Rate (CFR) and hospitalization rates for each of five pandemic severity categories, with CFR ranging from 0.1% to 2.5%.

RESULTS

For a pandemic with basic reproduction number R0 = 1.8, adopting no interventions resulted in total costs ranging from $441 per person for a pandemic at category 1 (CFR 0.1%) to $8,550 per person at category 5 (CFR 2.5%). For severe pandemics of category 3 (CFR 0.75%) and greater, a strategy combining antiviral treatment and prophylaxis, extended school closure and community contact reduction resulted in the lowest total cost of any strategy, costing $1,584 per person at category 5. This strategy was highly effective, reducing the attack rate to 5%. With low severity pandemics costs are dominated by productivity losses due to illness and social distancing interventions, whereas higher severity pandemic costs are dominated by healthcare costs and costs arising from productivity losses due to death.

CONCLUSIONS

For pandemics in high severity categories the strategies with the lowest total cost to society involve rigorous, sustained social distancing, which are considered unacceptable for low severity pandemics due to societal disruption and cost.

Epidemiological consequences of household-based antiviral prophylaxis for pandemic influenza

Antiviral treatment offers a fast acting alternative to vaccination; as such it is viewed as a first-line of defence against pandemic influenza in protecting families and households once infection has been detected. In clinical trials, antiviral treatments have been shown to be efficacious in preventing infection, limiting disease and reducing transmission, yet their impact at containing the 2009 influenza A(H1N1)pdm outbreak was limited. To understand this seeming discrepancy, we develop a general and computationally efficient model for studying household-based interventions. This allows us to account for uncertainty in quantities relevant to the 2009 pandemic in a principled way, accounting for the heterogeneity and variability in each epidemiological process modelled. We find that the population-level effects of delayed antiviral treatment and prophylaxis mean that their limited overall impact is quantitatively consistent (at current levels of precision) with their reported clinical efficacy under ideal conditions. Hence, effective control of pandemic influenza with antivirals is critically dependent on early detection and delivery ideally within 24 h.

Selecting nonpharmaceutical strategies to minimize influenza spread: the 2009 influenza A (H1N1) pandemic and beyond

Shortly after the influenza A (H1N1) 2009 pandemic began, the U.S. government provided guidance to state and local authorities to assist decision-making for the use of nonpharmaceutical strategies to minimize influenza spread. This guidance included recommendations for flexible decision-making based on outbreak severity, and it allowed for uncertainty and course correction as the pandemic progressed. These recommendations build on a foundation of local, collaborative planning and posit a series of questions regarding epidemiology, the impact on the health-care system, and locally determined feasibility and acceptability of nonpharmaceutical strategies. This article describes -recommendations and key questions for decision makers.

Interest of a simple on-line screening registry for measuring ICU burden related to an influenza pandemic

INTRODUCTION

The specific burden imposed on Intensive Care Units (ICUs) during the A/H1N1 influenza 2009 pandemic has been poorly explored. An on-line screening registry allowed a daily report of ICU beds occupancy rate by flu infected patients (Flu-OR) admitted in French ICUs.

METHODS

We conducted a prospective inception cohort study with results of an on-line screening registry designed for daily assessment of ICU burden.

RESULTS

Among the 108 centers participating to the French H1N1 research network on mechanical ventilation (REVA) - French Society of Intensive Care (SRLF) registry, 69 ICUs belonging to seven large geographical areas voluntarily participated in a website screening-registry. The aim was to daily assess the ICU beds occupancy rate by influenza-infected and non-infected patients for at least three weeks. Three hundred ninety-one critically ill infected patients were enrolled in the cohort, representing a subset of 35% of the whole French 2009 pandemic cohort; 73% were mechanically ventilated, 13% required extra corporal membrane oxygenation (ECMO) and 22% died. The global Flu-OR in these ICUs was only 7.6%, but it exceeded a predefined 15% critical threshold in 32 ICUs for a total of 103 weeks. Flu-ORs were significantly higher in University than in non-University hospitals. The peak ICU burden was poorly predicted by observations obtained at the level of large geographical areas.

CONCLUSIONS

The peak Flu-OR during the pandemic significantly exceeded a 15% critical threshold in almost half of the ICUs, with an uneven distribution with time, geographical areas and between University and non-University hospitals. An on-line assessment of Flu-OR via a simple dedicated registry may contribute to better match resources and needs.

Interleukin-6 is a potential biomarker for severe pandemic H1N1 influenza A infection

Pandemic H1N1 influenza A (H1N1pdm) is currently a dominant circulating influenza strain worldwide. Severe cases of H1N1pdm infection are characterized by prolonged activation of the immune response, yet the specific role of inflammatory mediators in disease is poorly understood. The inflammatory cytokine IL-6 has been implicated in both seasonal and severe pandemic H1N1 influenza A (H1N1pdm) infection. Here, we investigated the role of IL-6 in severe H1N1pdm infection. We found IL-6 to be an important feature of the host response in both humans and mice infected with H1N1pdm. Elevated levels of IL-6 were associated with severe disease in patients hospitalized with H1N1pdm infection. Notably, serum IL-6 levels associated strongly with the requirement of critical care admission and were predictive of fatal outcome. In C57BL/6J, BALB/cJ, and B6129SF2/J mice, infection with A/Mexico/4108/2009 (H1N1pdm) consistently triggered severe disease and increased IL-6 levels in both lung and serum. Furthermore, in our lethal C57BL/6J mouse model of H1N1pdm infection, global gene expression analysis indicated a pronounced IL-6 associated inflammatory response. Subsequently, we examined disease and outcome in IL-6 deficient mice infected with H1N1pdm. No significant differences in survival, weight loss, viral load, or pathology were observed between IL-6 deficient and wild-type mice following infection. Taken together, our findings suggest IL-6 may be a potential disease severity biomarker, but may not be a suitable therapeutic target in cases of severe H1N1pdm infection due to our mouse data.

Understanding and Governing Public Health Risks by Modeling

Increase in the use and development of computational tools to govern public health risks invites us to study their benefits and limitations. To analyze how risk is perceived and expressed through these tools is relevant to risk theory. This chapter clarifies the different concepts of risk, contrasting especially the mathematically expressed ones with culturally informed notions, which address a broader view on risk. I will suggest that a fruitful way to contextualize computational tools, such mathematical models in risk assessment is “analytics of risk,” which ties together the technological, epistemological, and political dimensions of the process of governance of risk. I will clarify the development of mathematical modeling techniques through their use in infectious disease epidemiology. Epidemiological modeling functions as a form of “risk calculation,” which provides predictions of the infectious outbreak in question. These calculations help direct and design preventive actions toward the health outcomes of populations. This chapter analyzes two cases in which modeling methods are used for explanation-based and scenario-building predictions in order to anticipate the risks of infections caused by Haemophilus influenzae type b bacteria and A(H1N1) pandemic influenza virus. I will address an interesting tension that arises when model-based estimates exemplify the population-level reasoning of public health risks but has restricted capacity to address risks on individual level. Analyzing this tension will lead to a fuller account to understand the benefits and limitations of computational tools in the governance of public health risks.

Burden of hospitalizations for pandemic influenza in Slovenia

AIM

To analyze the 2009/2010 epidemiological data of patients hospitalized for confirmed pandemic influenza in Slovenia.

METHODS

We conducted a retrospective analysis of health statistical data collected in an electronic data set Diagnosis-related Group system. Data on age, sex, primary and secondary diagnoses, duration of hospital stay, admission to the intensive care unit, disease outcome, and the week of the admission to the hospital were extracted for patients diagnosed with confirmed influenza virus infection.

RESULTS

A total of 748 (hospitalization rate 37.4/100,000) patients diagnosed with confirmed influenza virus infection were admitted to 19 public hospitals and 7 private acute care providers during the period from September 28, 2009 to April 11, 2010. The highest admission rate was recorded for mid-November 2009. Out of 748 hospitalized patients, 411 (55%) were children younger than 15 years. Influenza was coded as the primary diagnosis in 536 patients. In 35% of the patients, influenza caused viral pneumonia. Fewer than one third of patients (28%) had a pre-existing chronic disease and/or condition predisposing them to complicated or adverse outcomes of influenza, most frequently chronic lung diseases, mainly asthma. A median hospital stay was 2 days for children and 5 days for adult patients. Longer hospitalization was required in patients who had a secondary diagnosis of influenza. Older male individuals suffering from pneumonia and chronic diseases were overrepresented among cases admitted to the intensive care units.

CONCLUSIONS

The epidemiological data extracted from the Diagnosis-related Group system in Slovenia were comparable with the data on pandemic patients published elsewhere.

From containment to community: Trigger points from the London pandemic (H1N1) 2009 influenza incident response

OBJECTIVE

In the UK, during the first wave of pandemic (H1N1) 2009 influenza, a national 'containment' strategy was employed from 25 April to 2 July 2009, with case finding, treatment of cases, contact tracing and prophylaxis of close contacts. The aim of the strategy was to delay the introduction and spread of pandemic flu in the UK, provide a better understanding of the course of the novel disease, and thereby allow more time for the development of treatment and vaccination options.

STUDY DESIGN

Descriptive study of the management of the containment phase of pandemic (H1N1) 2009 influenza.

METHODS

Analysis of data reported to the London Flu Response Centre (LFRC).

RESULTS

The average number of telephone calls and faxes per day from health professionals before 15 June 2009 was 188, but this started to rise from 363 on 12 June, to 674 on 15 June, and peaked on 22 June at 2206 calls. The number of cases confirmed [by pandemic (H1N1) 2009 influenza specific H1 and N1 polymerase chain reaction] in London rose to a peak of 200 cases per day. There were widespread school outbreaks reporting large numbers of absences with influenza-like illnesses. Activity in the LFRC intensified to a point where London was declared a 'hot spot' for pandemic (H1N1) 2009 influenza on 19 June 2009 because of sustained community transmission. The local incident response was modified to the 'outbreak management phase' of the containment phase.

CONCLUSIONS

The sharp rise in the number of telephone calls and the rise in school outbreaks appeared to be trigger points for community transmission. These indicators should inform decisions on modifying public health strategy in pandemic situations.

Differential diagnosis of pandemic (H1N1) 2009 infection by detection of haemagglutinin with an enzyme-linked immunoassay

A sensitive and convenient immunoassay that can directly differentiate pandemic (H1N1) 2009 (pH1N1) virus from seasonal influenza virus can play an important role in the clinic. In the presented study, a double-sandwich ELISA (pH1N1 ELISA), based on two monoclonal antibodies against haemagglutinin (HA) of the pH1N1 virus, was developed. After laboratory determination of the sensitivity and specificity characteristics, the performance of this assay was evaluated in a cohort of 904 patients with influenza-like illness. All seven strains of pH1N1 virus tested were positive by pH1N1 ELISA, with an average lower detection limit of 10(3.0 ± 0.4) tissue culture infective dose (TCID)(50) /mL (or 0.009 ± 0.005 HA titre). Cross-reaction of the assay with seasonal influenza virus and other common respiratory pathogens was rare. In pH1N1-infected patients, the sensitivity of the pH1N1 ELISA was 92.3% (84/91, 95% CI 84.8-96.9%), which is significantly higher than that of the BD Directigen EZ Flu A + B test (70.3%, p <0.01). The specificity of pH1N1 ELISA in seasonal influenza A patients was 100.0% (171/171, 95% CI 97.9-100.0%), similar to that in non-influenza A patients (640/642, 99.7%, 95% CI 98.9-100.0%). The positive predictive value for pH1N1 ELISA was 97.7% and the negative predictive value was 99.1% in this study population with a pH1N1 prevalence of 10.1%. In conclusion, detection of HA of pH1N1 virus by immunoassay appears to be a convenient and reliable method for the differential diagnosis of pH1N1 from other respiratory pathogens, including seasonal influenza virus.

The impact of case diagnosis coverage and diagnosis delays on the effectiveness of antiviral strategies in mitigating pandemic influenza A/H1N1 2009

BACKGROUND

Neuraminidase inhibitors were used to reduce the transmission of pandemic influenza A/H1N1 2009 at the early stages of the 2009/2010 pandemic. Policies for diagnosis of influenza for the purposes of antiviral intervention differed markedly between and within countries, leading to differences in the timing and scale of antiviral usage.

METHODOLOGY/PRINCIPAL FINDINGS

The impact of the percentage of symptomatic infected individuals who were diagnosed, and of delays to diagnosis, for three antiviral intervention strategies (each with and without school closure) were determined using a simulation model of an Australian community. Epidemic characteristics were based on actual data from the A/H1N1 2009 pandemic including reproduction number, serial interval and age-specific infection rate profile. In the absence of intervention an illness attack rate (AR) of 24.5% was determined from an estimated R(0) of 1.5; this was reduced to 21%, 16.5% or 13% by treatment-only, treatment plus household prophylaxis, or treatment plus household plus extended prophylaxis antiviral interventions respectively, assuming that diagnosis occurred 24 hours after symptoms arose and that 50% of symptomatic cases were diagnosed. If diagnosis occurred without delay, ARs decreased to 17%, 12.2% or 8.8% respectively. If 90% of symptomatic cases were diagnosed (with a 24 hour delay), ARs decreased to 17.8%, 11.1% and 7.6%, respectively.

CONCLUSION

The ability to rapidly diagnose symptomatic cases and to diagnose a high proportion of cases was shown to improve the effectiveness of all three antiviral strategies. For epidemics with R(0)< = 1.5 our results suggest that when the case diagnosis coverage exceeds ∼70% the size of the antiviral stockpile required to implement the extended prophylactic strategy decreases. The addition of at least four weeks of school closure was found to further reduce cumulative and peak attack rates and the size of the required antiviral stockpile.

Reflections on pandemic (H1N1) 2009 and the international response

Gabriel Leung and Angus Nicoll provide their reflections on the international response to the 2009 H1N1 influenza pandemic, including what went well and what changes need to be made in anticipation of future flu pandemics.

Developing guidelines for school closure interventions to be used during a future influenza pandemic

Background

The A/H1N1 2009 influenza pandemic revealed that operational issues of school closure interventions, such as when school closure should be initiated (activation trigger), how long schools should be closed (duration) and what type of school closure should be adopted, varied greatly between and within countries. Computer simulation can be used to examine school closure intervention strategies in order to inform public health authorities as they refine school closure guidelines in light of experience with the A/H1N1 2009 pandemic.

Methods

An individual-based simulation model was used to investigate the effectiveness of school closure interventions for influenza pandemics with R₀ of 1.5, 2.0 and 2.5. The effectiveness of individual school closure and simultaneous school closure were analyzed for 2, 4 and 8 weeks closure duration, with a daily diagnosed case based intervention activation trigger scheme. The effectiveness of combining antiviral drug treatment and household prophyaxis with school closure was also investigated.

Results

Illness attack rate was reduced from 33% to 19% (14% reduction in overall attack rate) by 8 weeks school closure activating at 30 daily diagnosed cases in the community for an influenza pandemic with R₀ = 1.5; when combined with antivirals a 19% (from 33% to 14%) reduction in attack rate was obtained. For R₀ >= 2.0, school closure would be less effective. An 8 weeks school closure strategy gives 9% (from 50% to 41%) and 4% (from 59% to 55%) reduction in attack rate for R₀ = 2.0 and 2.5 respectively; however, school closure plus antivirals would give a significant reduction (~15%) in over all attack rate. The results also suggest that an individual school closure strategy would be more effective than simultaneous school closure.

Conclusions

Our results indicate that the particular school closure strategy to be adopted depends both on the disease severity, which will determine the duration of school closure deemed acceptable, and its transmissibility. For epidemics with a low transmissibility (R₀ < 2.0) and/or mild severity, individual school closures should begin once a daily community case count is exceeded. For a severe, highly transmissible epidemic (R₀ >= 2.0), long duration school closure should begin as soon as possible and be combined with other interventions.

Influence of country of study on student responsiveness to the H1N1 pandemic

Objectives

University students, both travelling abroad on holiday or exchange students entering a country, can serve as mobile carriers of infectious diseases during a pandemic, and thus require special attention when considering preventive measures. The objectives of this study were to evaluate student compliance and opinions on preventive measures of a university before and during an H1N1 influenza pandemic, and to explore environmental and behavioural factors that might contribute towards compliance.

Study design

Cross-sectional, self-administered questionnaire.

Methods

Local and foreign students attending an international summer school programme were invited to participate in a self-administered survey.

Results

Respondents complied with most of the preventive measures, excluding website viewing and mask wearing. Significant differences in compliance and perceived necessity were found amongst students from Singapore, Hong Kong and the USA. Singaporean students were significantly more likely to comply with all measures and consume antiviral medication in response to the pandemic than students studying in the US.

Conclusions

Students’ responses towards university pandemic measures were largely positive, but sensitivity towards these measures varied between groups by country of study. This should be considered in further comparative studies.

Experience and lessons from surveillance and studies of the 2009 pandemic in Europe

Surveillance and studies in a pandemic is a complex topic including four distinct components: (1) early detection and investigation; (2) comprehensive early assessment; (3) monitoring; and (4) rapid investigation of the effectiveness and impact of countermeasures, including monitoring the safety of pharmaceutical countermeasures. In the 2009 pandemic, the prime early detection and investigation took place in the Americas, but Europe needed to undertake the other three components while remaining vigilant to new phenomenon such as the emergence of antiviral resistance and important viral mutation. Laboratory-based surveillance was essential and also integral to epidemiological and clinical surveillance. Early assessment was especially vital because of the many important strategic parameters of the pandemic that could not be anticipated (the 'known unknowns'). Such assessment did not need to be undertaken in every country, and was done by the earliest affected European countries, particularly those with stronger surveillance. This was more successful than requiring countries to forward primary data for central analysis. However, it sometimes proved difficult to get even those analyses from European counties, and information from Southern hemisphere countries and North America proved equally valuable. These analyses informed which public health and clinical measures were most likely to be successful, and were summarized in a European risk assessment that was updated repeatedly. The estimate of the severity of the pandemic by the World Health Organization (WHO), and more detailed description by the European Centre for Disease Prevention and Control in the risk assessment along with revised planning assumptions were essential, as most national European plans envisaged triggering more disruptive interventions in the event of a severe pandemic. Setting up new surveillance systems in the midst of the pandemic and getting information from them was generally less successful. All European countries needed to perform monitoring (Component 3) for the proper management of their own healthcare systems and other services. The information that central authorities might like to have for monitoring was legion, and some countries found it difficult to limit this to what was essential for decisions and key communications. Monitoring should have been tested for feasibility in influenza seasons, but also needed to consider what surveillance systems will change or cease to deliver during a pandemic. International monitoring (reporting upwards to WHO and European authorities) had to be kept simple as many countries found it difficult to provide routine information to international bodies as well as undertaking internal processes. Investigation of the effectiveness of countermeasures (and the safety of pharmaceutical countermeasures) (Component 4) is another process that only needs to be undertaken in some countries. Safety monitoring proved especially important because of concerns over the safety of vaccines and antivirals. It is unlikely that it will become clear whether and which public health measures have been successful during the pandemic itself. Piloting of methods of estimating influenza vaccine effectiveness (part of Component 4) in Europe was underway in 2008. It was concluded that for future pandemics, authorities should plan how they will undertake Components 2-4, resourcing them realistically and devising new ways of sharing analyses.

First evidence of a pro-inflammatory response to severe infection with influenza virus H1N1

The great majority of infections caused by the pandemic variant of the influenza virus (nvH1N1) are self-limited, but a small percentage of patients develop severe symptoms requiring hospitalization. Bermejo-Martin and colleagues have presented a pilot study describing the differences in the early immune response for patients both mildly and severely infected with nvH1N1. Patients who develop severe symptoms after nvH1N1 infection showed Th1 and Th17 'hypercytokinemia', compared to mildly infected patients and healthy controls. The mediators involved with the Th1 and Th17 profiles are known to be involved in antiviral, pro-inflammatory and autoimmune responses. This is the first work reporting the association of a pro-inflamatory immune response with a severe pandemic infection, although it is likely that more studies are needed to understand the detrimental or beneficial roles these cytokines play in the evolution of mild and severe nvH1N1 infection.

Th1 and Th17 hypercytokinemia as early host response signature in severe pandemic influenza

Introduction

Human host immune response following infection with the new variant of A/H1N1 pandemic influenza virus (nvH1N1) is poorly understood. We utilize here systemic cytokine and antibody levels in evaluating differences in early immune response in both mild and severe patients infected with nvH1N1.

Methods

We profiled 29 cytokines and chemokines and evaluated the haemagglutination inhibition activity as quantitative and qualitative measurements of host immune responses in serum obtained during the first five days after symptoms onset, in two cohorts of nvH1N1 infected patients. Severe patients required hospitalization (n = 20), due to respiratory insufficiency (10 of them were admitted to the intensive care unit), while mild patients had exclusively flu-like symptoms (n = 15). A group of healthy donors was included as control (n = 15). Differences in levels of mediators between groups were assessed by using the non parametric U-Mann Whitney test. Association between variables was determined by calculating the Spearman correlation coefficient. Viral load was performed in serum by using real-time PCR targeting the neuraminidase gene.

Results

Increased levels of innate-immunity mediators (IP-10, MCP-1, MIP-1β), and the absence of anti-nvH1N1 antibodies, characterized the early response to nvH1N1 infection in both hospitalized and mild patients. High systemic levels of type-II interferon (IFN-γ) and also of a group of mediators involved in the development of T-helper 17 (IL-8, IL-9, IL-17, IL-6) and T-helper 1 (TNF-α, IL-15, IL-12p70) responses were exclusively found in hospitalized patients. IL-15, IL-12p70, IL-6 constituted a hallmark of critical illness in our study. A significant inverse association was found between IL-6, IL-8 and PaO2 in critical patients.

Conclusions

While infection with the nvH1N1 induces a typical innate response in both mild and severe patients, severe disease with respiratory involvement is characterized by early secretion of Th17 and Th1 cytokines usually associated with cell mediated immunity but also commonly linked to the pathogenesis of autoimmune/inflammatory diseases. The exact role of Th1 and Th17 mediators in the evolution of nvH1N1 mild and severe disease merits further investigation as to the detrimental or beneficial role these cytokines play in severe illness.

[Influenza pandemic (H1N1) 2009]

In the past, influenza pandemics have been occurring every 20 to 30 years. Highly pathogenic avian influenza A(H5N1) has been causing unprecedented global outbreaks since 2003 and many human cases with a high case fatality rate have also been reported. But the virus that caused a pandemic in 2009 was A(H1N1) that was originated from swine influenza. The same subtype, A(H1N1) has been circulating in human population since 1977. This pandemic (H1N1) 2009 is also not as virulent as A(H5N1) in humans. Many aspects of pandemic (H1N1) 2009 are different from what we had been expecting. We should reconsider the concepts and the strategies for influenza pandemic by reviewing current pandemic (H1N1).

The novel influenza A (H1N1) virus pandemic: An update

In the 4 months since it was first recognized, the pandemic strain of a novel influenza A (H1N1) virus has spread to all continents and, after documentation of human-to-human transmission of the virus in at least three countries in two separate World Health Organization (WHO) regions, the pandemic alert was raised to level 6. The agent responsible for this pandemic, a swine-origin influenza A (H1N1) virus (S-OIV), is characterized by a unique combination of gene segments that has not previously been identified among human or swine influenza A viruses. As of 31th July 2009, 168 countries and overseas territories/communities have each reported at least one laboratory-confirmed case of pandemic H1N1 infection. There have been a total of 162,380 reported cases and 1154 associated deaths. Influenza epidemics usually take off in autumn, and it is important to prepare for an earlier start this season. Estimates from Europe indicate that 230 millions Europe inhabitants will have clinical signs and symptoms of S-OIV this autumn, and 7- 35% of the clinical cases will have a fatal outcome, which means that there will be 160,000- 750,000 H1N1-related deaths. A vaccine against H1N1 is expected to be the most effective tool for controlling influenza A (H1N1) infection in terms of reducing morbidity and mortality and limiting diffusion. However, there are several issues with regard to vaccine manufacture and approval, as well as production capacity, that remain unsettled. We searched the literature indexed in PubMed as well as the websites of major international health agencies to obtain the material presented in this update on the current S-OIV pandemic.

Nieuwe influenza A (H1N1) - Mexicaanse griep

Het viel te verwacht dat het nieuwe influenzavirus bij veel tandartsen en mondhygiënisten vragen oproept in verband met de kans op besmetting in de praktijk. Enkele van deze vragen waren: