Modelling the health-economic impact of the next influenza pandemic in The Netherlands

The Economic Impact of Lockdowns: A Persistent Inoperability Input-Output Approach

The COVID-19 pandemic has forced governments around the world to implement unprecedented lockdowns, mandating businesses to shut down for extended periods of time. Previous studies have modeled the impact of disruptions to the economy at static and dynamic settings. This study develops a model to fulfil the need to account for the sustained disruption resulting from the extended shutdown of business operations. Using a persistent inoperability input-output model (PIIM), we are able to show that (1) sectors that suffer higher levels of inoperability during quarantine period may recover faster depending on their resilience; (2) initially unaffected sectors can suffer inoperability levels higher than directly affected sectors over time; (3) the economic impact on other regions not under lockdown is also significant.

Comparative Analysis of the Japanese Version of the Revised Impact of Event Scale: A Study of Firefighters

Introduction:

The Impact of Event Scale Revised (IES-R) has been used in various epidemiological studies to assess the prevalence of post-traumatic stress disorder (PTSD). Previous studies using the IES-R Japanese version to assess the mental health of firefighters were based on the premise that firefighters had experienced a traumatic event(s) as a matter of course. However, use of the IES-R-J does not indicate whether or not a traumatic event was experienced. The purpose of this study is to clarify the differences between: (1) IES-R-J high and low score groups; and (2) those who report symptoms similar to those of PTSD with and without having been being exposed to a traumatic event.

Methods:

Questionnaire packets distributed to all 157 workers in a Japanese fire station included the IES-R, the Japan Brief Job Stress Questionnaire, a questionnaire regarding traumatic event experiences, and demographic questions. Participants who scored ≥25 points on the IES-R-J scale were defined as the PTSD high risk (HR) group; those with scores <25 points as the PTSD low risk (LR) group.

Results:

One hundred thirty-one of the 157 subjects (83.4%) responded to the questionnaire; three were excluded from the analysis because of missing data. The mean total IES-R-J score was 14.9 ±15.2. Twenty-eight subjects scored in the PTSD HR group (≥25); 100 scored in the LR group (<25). A total of 54 (42.2%) participants had experienced a traumatic event; 57.8% had not. In the HR group, 14 subjects had experienced a traumatic event and 14 had not. Participants who had experienced a traumatic event reported a higher incidence of intrusion/re-experience symptoms than did those who had not experienced a traumatic event. The level of social support significantly affected the risk for PTSD.

Firefighters who scored ≥25 on the IES-R-J and, thus, considered to be at high risk for the development of PTSD, were less confident about their health, experienced more job stressors and had less social support than did those whose IES-R-J scores were <25. Having experienced a traumatic event was reported by only 42% of all the participants and by only 50% of those in the high risk PTSD group.

Conclusions:

Although the IES-R is an easily-administered tool useful in epidemiological studies evaluating psychological stress, it is recommended that the questionnaire be amended to include a question regarding the existence of a threatened experience or event and to analyze the data using positive and negative predictive value methodology.

Simulating school closure policies for cost effective pandemic decision making

BACKGROUND

Around the globe, school closures were used sporadically to mitigate the 2009 H1N1 influenza pandemic. However, such closures can detrimentally impact economic and social life.

METHODS

Here, we couple a decision analytic approach with a mathematical model of influenza transmission to estimate the impact of school closures in terms of epidemiological and cost effectiveness. Our method assumes that the transmissibility and the severity of the disease are uncertain, and evaluates several closure and reopening strategies that cover a range of thresholds in school-aged prevalence (SAP) and closure durations.

RESULTS

Assuming a willingness to pay per quality adjusted life-year (QALY) threshold equal to the US per capita GDP ($46,000), we found that the cost effectiveness of these strategies is highly dependent on the severity and on a willingness to pay per QALY. For severe pandemics, the preferred strategy couples the earliest closure trigger (0.5% SAP) with the longest duration closure (24 weeks) considered. For milder pandemics, the preferred strategies also involve the earliest closure trigger, but are shorter duration (12 weeks for low transmission rates and variable length for high transmission rates).

CONCLUSIONS

These findings highlight the importance of obtaining early estimates of pandemic severity and provide guidance to public health decision-makers for effectively tailoring school closures strategies in response to a newly emergent influenza pandemic.

Dynamics of Single-City Influenza with Seasonal Forcing: From Regularity to Chaos

Seasonal and epidemic influenza continue to cause concern, reinforced by connections between human and avian influenza, and H1N1 swine influenza. Models summarize ideas about disease mechanisms, help understand contributions of different processes, and explore interventions. A compartment model of single-city influenza is developed. It is mechanism-based on lower-level studies, rather than focussing on predictions. It is deterministic, without non-disease-status stratification. Categories represented are susceptible, infected, sick, hospitalized, asymptomatic, dead from flu, recovered, and one in which recovered individuals lose immunity. Most categories are represented with sequential pools with first-order kinetics, giving gamma-function progressions with realistic dynamics. A virus compartment allows representation of environmental effects on virus lifetime, thence affecting reproductive ratio. The model's behaviour is explored. It is validated without significant tuning against data on a school outbreak. Seasonal forcing causes a variety of regular and chaotic behaviours, some being typical of seasonal and epidemic flu. It is suggested that models use sequential stages for appropriate disease categories because this is biologically realistic, and authentic dynamics is required if predictions are to be credible. Seasonality is important indicating that control measures might usefully take account of expected weather.

Knowledge, attitudes, and practices concerning infection control among travelers between Taiwan and mainland China

With an increase in the number of travelers around the world in recent years, widespread efforts to control the human-transmissible influenza and increased surveillance among poultry and humans should be given the highest priority. The purpose of this article is to describe an examination of the passengers traveling via "mini links" from Xiamen (China) to Kinmen (Taiwan) with reference to their knowledge and practice on infection control measures and satisfaction with public health policies. A survey of perceptions, attitudes, and practices was accordingly carried out. Although some research has been conducted on selected health topics and patients, little research has examined the perceptions of normal travelers. The results demonstrate that travelers' perception of risk for infection control was high; by contrast, their practices were not sufficient. The content analysis of this study also provides an empirical starting point for future research into combining travelers' knowledge and practice on disease problems with the worldwide public health policies.

Workplace vaccination and other factors impacting influenza vaccination decision among employees in Israel

The study examined the factors affecting the decision to be vaccinated against influenza among employees in Israel. The research, conducted in 2007/2008, included 616 employees aged 18−65 at various workplaces in Israel, among them companies that offered their employees influenza vaccination. The research questionnaire included socio-demographic characteristics, and the Health Belief Model principles. The results show that the significant factors affecting vaccination compliance include a vaccination program at workplaces, vaccinations in the past, higher levels of vaccine’s perceived benefits, and lower levels of barriers to getting the vaccine. We conclude that vaccine compliance is larger at companies with workplace vaccination programs providing easier accessibility to vaccination.

Mitigation of pandemic influenza: review of cost-effectiveness studies

We conducted a review of economic evaluations of pandemic influenza control measures. In the studies found, we detected various interventions being investigated: antiviral stockpiling and treatment, prophylaxis, vaccination, school closure and restricting international travel. Cost-effectiveness varied but often showed potentials for the favorable economic profiles of these measures. Both static and dynamic models were used. We conclude that the choice of an appropriate model - in particular, a dynamic model - is crucial to arrive at valid cost-effectiveness ratios. Yet, of the economic evaluations considered here, only a few were based on dynamic modeling. We recommend that further research is directed toward linking dynamic epidemiological models for pandemic spread with economic outcomes by considering the full impacts on national economies, including direct, indirect, medical and nonmedical costs.

Epidemic patch models applied to pandemic influenza: contact matrix, stochasticity, robustness of predictions

Due to the recent emergence of H5N1 virus, the modelling of pandemic influenza has become a relevant issue. Here we present an SEIR model formulated to simulate a possible outbreak in Italy, analysing its structure and, more generally, the effect of including specific details into a model. These details regard population heterogeneities, such as age and spatial distribution, as well as stochasticity, that regulates the epidemic dynamics when the number of infectives is low. We discuss and motivate the specific modelling choices made when building the model and investigate how the model details influence the predicted dynamics. Our analysis may help in deciding which elements of complexity are worth including in the design of a deterministic model for pandemic influenza, in a balance between, on the one hand, keeping the model computationally efficient and the number of parameters low and, on the other hand, maintaining the necessary realistic features.

Influenza pandemic: perception of risk and individual precautions in a general population. Cross sectional study

Background

An influenza pandemic may have considerable impact on health and societal functioning. The aim of this study was to explore people's reflections on the consequences of a pandemic.

Methods

Cross-sectional web-based survey of 1,168 Norwegians aged 16–82 years. The main outcome measures were answers to questions about a potential pandemic ("serious influenza epidemic"): statements about personal precautions including stockpiling Tamiflu^®, the perceived number of fatalities, the perceived effects of Tamiflu^®, the sources of information about influenza and trust in public information.

Results

While 80% of the respondents stated that they would be "careful about personal hygiene", only a few would stay away from work (2%), or move to an isolated place (4%). While 27% of respondents were uncertain about the number of fatalities during an influenza pandemic, 48% thought it would be lower than the estimate of Norwegian health authorities (0.05%–1%) and only 3% higher. At least half of the respondents thought that Tamiflu^® might reduce the mortality risk, but less than 1% had personally purchased the drug. The great majority had received their information from the mass media, and only 9% directly from health authorities. Still the majority (65%) trusted information from the authorities, and only 9% reported overt distrust.

Conclusion

In Norway, considerable proportions of people seem to consider the mortality risk during a pandemic less than health authorities do. Most people seem to be prepared to take some, but not especially disruptive, precautions.