School closures during the 2009 influenza pandemic: national and local experiences.

BACKGROUND: School closure is a non-pharmaceutical intervention that was considered in many national pandemic plans developed prior to the start of the influenza A(H1N1)pdm09 pandemic, and received considerable attention during the event. Here, we retrospectively review and compare national and local experiences with school closures in several countries during the A(H1N1)pdm09 pandemic. Our intention is not to make a systematic review of country experiences; rather, it is to present the diversity of school closure experiences and provide examples from national and local perspectives. METHODS: Data were gathered during and following a meeting, organized by the European Centres for Disease Control, on school closures held in October 2010 in Stockholm, Sweden. A standard data collection form was developed and sent to all participants. The twelve participating countries and administrative regions (Bulgaria, China, France, Hong Kong Special Administrative Region (SAR), Italy, Japan, New Zealand, Serbia, South Africa, Thailand, United Kingdom, and United States) provided data. RESULTS: Our review highlights the very diverse national and local experiences on school closures during the A(H1N1)pdm09 pandemic. The processes including who was in charge of making recommendations and who was in charge of making the decision to close, the school-based control strategies, the extent of school closures, the public health tradition of responses and expectations on school closure varied greatly between countries. Our review also discusses the many challenges associated with the implementation of this intervention and makes recommendations for further practical work in this area. CONCLUSIONS: The single most important factor to explain differences observed between countries may have been the different public health practises and public expectations concerning school closures and influenza in the selected countries.

Modelling the risk-benefit impact of H1N1 influenza vaccines.

BACKGROUND: Shortly after the H1N1 influenza virus reached pandemic status in June 2009, the benefit-risk project team at the European Medicines Agency recognized this presented a research opportunity for testing the usefulness of a decision analysis model in deliberations about approving vaccines soon based on limited data or waiting for more data. Undertaken purely as a research exercise, the model was not connected to the ongoing assessment by the European Medicines Agency, which approved the H1N1 vaccines on 25 September 2009. METHODS: A decision tree model constructed initially on 1 September 2009, and slightly revised subsequently as new data were obtained, represented an end-of-September or end-of-October approval of vaccines. The model showed combinations of uncertain events, the severity of the disease and the vaccines' efficacy and safety, leading to estimates of numbers of deaths and serious disabilities. The group based their probability assessments on available information and background knowledge about vaccines and similar pandemics in the past. RESULTS: Weighting the numbers by their joint probabilities for all paths through the decision tree gave a weighted average for a September decision of 216 500 deaths and serious disabilities, and for a decision delayed to October of 291 547, showing that an early decision was preferable. CONCLUSIONS: The process of constructing the model facilitated communications among the group's members and led to new insights for several participants, while its robustness built confidence in the decision. These findings suggest that models might be helpful to regulators, as they form their preferences during the process of deliberation and debate, and more generally, for public health issues when decision makers face considerable uncertainty.

Developing pandemic preparedness in Europe in the 21st century: experience, evolution and next steps.

PROBLEM: Improving pandemic planning and preparedness is a challenge in Europe, a diverse region whose regional bodies (the Regional Office for Europe of the World Health Organization [WHO], the European Commission and the European Centre for Disease Prevention and Control) have overlapping roles and responsibilities. APPROACH: European pandemic preparedness indicators were used to develop an assessment tool and procedure based on the 2005 global WHO checklist for pandemic preparedness. These were then applied to Member States of WHO's European Region, initially as part of structured national assessments conducted during short visits by external teams. LOCAL SETTING: Countries in WHO's European Region. RELEVANT CHANGES: From 2005 to 2008, 43 countries underwent a pandemic preparedness assessment that included a short external assessment visit by an expert team. These short visits developed into a longer self-assessment procedure involving an external team but "owned" by the countries, which identified gaps and developed plans for improving preparedness. The assessment tool and procedure became more sophisticated as national and local pandemic preparedness became more complex. The 2009 pandemic revealed new gaps in planning, surveillance communications and immunization. LESSONS LEARNT: Structured national self-assessments with support from external teams allow individual countries to identify gaps in their pandemic preparedness plans and enable regional bodies to assess the regional and global resources that such plans require. The 2009 pandemic revealed additional problems with surveillance, pandemic severity estimates, the flexibility of the response, vaccination, involvement of health-care workers and communication. European national plans are being upgraded and global leadership is required to ensure that these plans are uniformly applied across the region.

Group B streptococcal disease in UK and Irish infants younger than 90 days.

The incidence, morbidity, and mortality of group B streptococcal disease in the UK and Republic of Ireland are largely unknown. Between Feb 1, 2000, and Feb 28, 2001, we identified cases of invasive group B streptococcal disease in infants younger than 90 days through surveillance involving paediatricians, microbiologists, and parents. 568 cases were identified, equivalent to a total incidence of 0.72 per 1000 live-births (95% CI 0.66-0.78); the incidence for early-onset disease (n=377) was 0.48 per 1000 (0.43-0.53), and for late-onset disease (n=191) was 0.24 per 1000 (0.21-0.28). Risk factors were identifiable for 218 (58%) cases of early-onset disease. 53 infants died (overall 9.7%). We have established the minimum current burden of group B streptococcal disease in UK and Irish infants. This information will assist in the formulation of guidelines for prevention of this disease.

Europe makes progress in preparing for influenza pandemic, but further work needed.

Progress has been made in influenza pandemic preparedness in Europe in the past six month.

The consortium for the standardization of influenza seroepidemiology (CONSISE): a global partnership to standardize influenza seroepidemiology and develop influenza investigation protocols to inform public health policy.

CONSISE - The consortium for the Standardization of Influenza Seroepidemiology - is a global partnership to develop influenza investigation protocols and standardize seroepidemiology to inform health policy. This international partnership was formed in 2011 and was created out of a need, identified during the 2009 H1N1 pandemic, for timely seroepidemiological data to better estimate pandemic virus infection severity and attack rates to inform policy decisions. CONSISE has developed into a consortium of two interactive working groups: epidemiology and laboratory, with a steering committee composed of individuals from several organizations. CONSISE has had two international meetings with more planned for 2013. We seek additional members from public health agencies, academic institutions and other interested parties.

Influenza serological studies to inform public health action: best practices to optimise timing, quality and reporting.

BACKGROUND: Serological studies can detect infection with a novel influenza virus in the absence of symptoms or positive virology, providing useful information on infection that goes beyond the estimates from epidemiological, clinical and virological data. During the 2009 A(H1N1) pandemic, an impressive number of detailed serological studies were performed, yet the majority of serological data were available only after the first wave of infection. This limited the ability to estimate the transmissibility and severity of this novel infection, and the variability in methodology and reporting limited the ability to compare and combine the serological data. OBJECTIVES: To identify best practices for conduct and standardisation of serological studies on outbreak and pandemic influenza to inform public policy. METHODS/SETTING: An international meeting was held in February 2011 in Ottawa, Canada, to foster the consensus for greater standardisation of influenza serological studies. RESULTS: Best practices for serological investigations of influenza epidemiology include the following: classification of studies as pre-pandemic, outbreak, pandemic or inter-pandemic with a clearly identified objective; use of international serum standards for laboratory assays; cohort and cross-sectional study designs with common standards for data collection; use of serum banks to improve sampling capacity; and potential for linkage of serological, clinical and epidemiological data. Advance planning for outbreak studies would enable a rapid and coordinated response; inclusion of serological studies in pandemic plans should be considered. CONCLUSIONS: Optimising the quality, comparability and combinability of influenza serological studies will provide important data upon emergence of a novel or variant influenza virus to inform public health action.

The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence.

There are limited data on the use of masks and respirators to reduce transmission of influenza. A systematic review was undertaken to help inform pandemic influenza guidance in the United Kingdom. The initial review was performed in November 2009 and updated in June 2010 and January 2011. Inclusion criteria included randomised controlled trials and quasi-experimental and observational studies of humans published in English with an outcome of laboratory-confirmed or clinically-diagnosed influenza and other viral respiratory infections. There were 17 eligible studies. Six of eight randomised controlled trials found no significant differences between control and intervention groups (masks with or without hand hygiene; N95/P2 respirators). One household trial found that mask wearing coupled with hand sanitiser use reduced secondary transmission of upper respiratory infection/influenza-like illness/laboratory-confirmed influenza compared with education; hand sanitiser alone resulted in no reduction. One hospital-based trial found a lower rate of clinical respiratory illness associated with non-fit-tested N95 respirator use compared with medical masks. Eight of nine retrospective observational studies found that mask and/or respirator use was independently associated with a reduced risk of severe acute respiratory syndrome (SARS). Findings, however, may not be applicable to influenza and many studies were suboptimal. None of the studies established a conclusive relationship between mask/respirator use and protection against influenza infection. Some evidence suggests that mask use is best undertaken as part of a package of personal protection especially hand hygiene. The effectiveness of masks and respirators is likely linked to early, consistent and correct usage.

The importance of influenza prevention for public health.

Annual epidemics of seasonal (inter-pandemic) influenza represent a significant burden on society in terms of morbidity, mortality, hospitalizations and lost working time. The impact of influenza depends on a mix of direct and indirect effects and is not easy to assess. Nevertheless there is a consensus in considering influenza prevention and mitigation high priorities for public health. We review the available evidence to assess the impact of influenza prevention focusing especially on vaccines and immunization strategies.

Comment on "Seroevidence for H5N1 influenza infections in humans: meta-analysis".

A better understanding of the severity of H5N1 in humans is needed. Wang et al. (Brevia, 23 March 2012, p. 1463; published online 23 February 2012) overinterpret the results of seroprevalence studies and take too little account of underlying uncertainties. Although the true risk of death from H5N1 infection will likely be lower than the 60% of reported laboratory-confirmed cases, there is little evidence of millions of missed infections.

Seroprevalence to influenza A(H1N1) 2009 virus--where are we?

Age-specific seroprevalences for influenza virus make important contributions to estimating the burden of infection and determining the vulnerable populations. It is especially difficult to know the true clinical attack rates of the 2009 influenza A(H1N1) pandemic; however, we can estimate infection rates through analyses of seroprevalences based on national studies from different continents and countries with different demographics. After the 2009 influenza A(H1N1) pandemic, seroprevalence studies found 5 to 60% of populations across different continents and age groups having antibodies against the A(H1N1) 2009 virus. The seropositivity was highest in children and teenagers (20 to 60%) as well as in the elderly older than 80 years (20 to 40%). Preexisting cross-reactive antibodies against the virus were present mostly in sera of older people (born before 1950) who could have encountered viruses descended from the 1918 pandemic viruses. Experience with the 2009 pandemic indicates how essential early and timely serology data against the emerging virus can be for informing decisions on use of antivirals and vaccination campaigns, especially in regard to risk groups. The objectives of this review were to summarize the current data available on seroprevalence before and after the 2009 influenza A(H1N1) pandemic and the lessons learned for future pandemic preparedness.