47,352 research outputs found

    Viral factors in influenza pandemic risk assessment

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    The threat of an influenza A virus pandemic stems from continual virus spillovers from reservoir species, a tiny fraction of which spark sustained transmission in humans. To date, no pandemic emergence of a new influenza strain has been preceded by detection of a closely related precursor in an animal or human. Nonetheless, influenza surveillance efforts are expanding, prompting a need for tools to assess the pandemic risk posed by a detected virus. The goal would be to use genetic sequence and/or biological assays of viral traits to identify those non-human influenza viruses with the greatest risk of evolving into pandemic threats, and/or to understand drivers of such evolution, to prioritize pandemic prevention or response measures. We describe such efforts, identify progress and ongoing challenges, and discuss three specific traits of influenza viruses (hemagglutinin receptor binding specificity, hemagglutinin pH of activation, and polymerase complex efficiency) that contribute to pandemic risk

    Age-specific mortality during the 1918 influenza pandemic: unravelling the mystery of high young adult mortality.

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    The worldwide spread of a novel influenza A (H1N1) virus in 2009 showed that influenza remains a significant health threat, even for individuals in the prime of life. This paper focuses on the unusually high young adult mortality observed during the Spanish flu pandemic of 1918. Using historical records from Canada and the U.S., we report a peak of mortality at the exact age of 28 during the pandemic and argue that this increased mortality resulted from an early life exposure to influenza during the previous Russian flu pandemic of 1889-90. We posit that in specific instances, development of immunological memory to an influenza virus strain in early life may lead to a dysregulated immune response to antigenically novel strains encountered in later life, thereby increasing the risk of death. Exposure during critical periods of development could also create holes in the T cell repertoire and impair fetal maturation in general, thereby increasing mortality from infectious diseases later in life. Knowledge of the age-pattern of susceptibility to mortality from influenza could improve crisis management during future influenza pandemics

    Healthcare Workers in Peril: Preparing to Protect Worker Health and Safety During Pandemic Influenza

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    [Excerpt] An influenza pandemic is projected to have a global impact requiring a sustained, large scale response from the healthcare community to provide care to sick patients. Healthcare workers will be at very high risk of becoming infected when caring for patients with pandemic flu unless adequate health and safety measures are in place, in advance of the pandemic, that will protect them. There is no existing comprehensive federal OSHA standard with mandatory and enforceable provisions that require planning and preparation designed to protect healthcare workers from exposures to pandemic influenza. Nevertheless, it is essential that workplaces plan and prepare for safety and health issues before the flu arrives

    Gauging U.S. Emergency Medical Services Workers' Willingness to Respond to Pandemic Influenza Using a Threat- and Efficacy-Based Assessment Framework

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    Emergency Medical Services workers' willingness to report to duty in an influenza pandemic is essential to healthcare system surge amidst a global threat. Application of Witte's Extended Parallel Process Model (EPPM) has shown utility for revealing influences of perceived threat and efficacy on non-EMS public health providers' willingness to respond in an influenza pandemic. We thus propose using an EPPM-informed assessment of EMS workers' perspectives toward fulfilling their influenza pandemic response roles.We administered an EPPM-informed snapshot survey about attitudes and beliefs toward pandemic influenza response, to a nationally representative, stratified random sample of 1,537 U.S. EMS workers from May-June 2009 (overall response rate: 49%). Of the 586 respondents who met inclusion criteria (currently active EMS providers in primarily EMS response roles), 12% indicated they would not voluntarily report to duty in a pandemic influenza emergency if asked, 7% if required. A majority (52%) indicated their unwillingness to report to work if risk of disease transmission to family existed. Confidence in personal safety at work (OR = 3.3) and a high threat/high efficacy ("concerned and confident") EPPM profile (OR = 4.7) distinguished those who were more likely to voluntarily report to duty. Although 96% of EMS workers indicated that they would probably or definitely report to work if they were guaranteed a pandemic influenza vaccine, only 59% had received an influenza immunization in the preceding 12 months.EMS workers' response willingness gaps pose a substantial challenge to prehospital surge capacity in an influenza pandemic. "Concerned and confident" EMS workers are more than four times as likely to fulfill pandemic influenza response expectations. Confidence in workplace safety is a positively influential modifier of their response willingness. These findings can inform insights into interventions for enhancing EMS workers' willingness to respond in the face of a global infectious disease threat

    Pandemic Influenza: Ethics, Law, and the Public\u27s Health

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    Highly pathogenic Influenza (HPAI) has captured the close attention of policy makers who regard pandemic influenza as a national security threat. Although the prevalence is currently very low, recent evidence that the 1918 pandemic was caused by an avian influenza virus lends credence to the theory that current outbreaks could have pandemic potential. If the threat becomes a reality, massive loss of life and economic disruption would ensue. Therapeutic countermeasures (e.g., vaccines and antiviral medications) and public health interventions (e.g., infection control, social separation, and quarantine) form the two principal strategies for prevention and response, both of which present formidable legal and ethical challenges that have yet to receive sufficient attention. In part II, we examine the major medical countermeasures being being considered as an intervention for an influenza pandemic. In this section, we will evaluate the known effectiveness of these interventions and analyze the ethical claims relating to distributive justice in the allocation of scarce resources. In part III, we will discuss public health interventions, exploring the hard tradeoffs between population health on the one hand and personal (e.g., autonomy, privacy, and liberty) and economic (e.g., trade, tourism, and business) interests on the other. This section will focus on the ethical and human rights issues inherent in population-based interventions. Pandemics can be deeply socially divisive, and the political response to these issues not only impacts public health preparedness, but also reflects profoundly on the kind of society we aspire to be

    Assessment of human influenza pandemic scenarios in Europe

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    The response to the emergence of the 2009 influenza A(H1N1) pandemic was the result of a decade of pandemic planning, largely centred on the threat of an avian influenza A(H5N1) pandemic. Based on a literature review, this study aims to define a set of new pandemic scenarios that could be used in case of a future influenza pandemic. A total of 338 documents were identified using a searching strategy based on seven combinations of keywords. Eighty-three of these documents provided useful information on the 13 virus-related and health-system-related parameters initially considered for describing scenarios. Among these, four parameters were finally selected (clinical attack rate, case fatality rate, hospital admission rate, and intensive care admission rate) and four different levels of severity for each of them were set. The definition of six most likely scenarios results from the combination of four different levels of severity of the four final parameters (256 possible scenarios). Although it has some limitations, this approach allows for more flexible scenarios and hence it is far from the classic scenarios structure used for pandemic plans until 2009

    Influenza A(H1N1) and Pandemic Preparedness Under the Rule of International Law

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    A novel strain of Influenza A (H1N1) spread rapidly through Mexico in April 2009 and now spans the globe. By the time WHO was notified and responded, geographical containment was not feasible, leading the agency to call for mitigation. The international outbreak of SARS in 2003 and the more recent Influenza A (H5N1) among birds with limited transmission to humans helped prepare the world for the current pandemic threat. SARS galvanized the WHO to revise the antiquated International Health Regulations (IHR) in 2005, which took effect June 15, 2007. Governments instituted preparedness plans in response to avian influenza. Despite increased preparedness, the WHO and US Centers for Disease Control and Prevention (CDC) lack key powers and resources. Reminiscent of past responses, many governments are acting out of fear or economic and political self-interest rather than scientific reason. Above all, there are serious questions of global justice, as Mexicans are subject to stigma and discrimination. This article by Lawrence O. Gostin, O’Neill Professor of Global Health Law at Georgetown University, analyses WHO powers and resources including the pandemic alert system and the IHR, as well as the powers and resources of the CDC. He finds that although the response to H1N1 has been strong, the WHO and CDC need more authority and resources to deal with pandemic threats under the rule of international law

    PLoS One

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    BackgroundEmergency Medical Services workers' willingness to report to duty in an influenza pandemic is essential to healthcare system surge amidst a global threat. Application of Witte's Extended Parallel Process Model (EPPM) has shown utility for revealing influences of perceived threat and efficacy on non-EMS public health providers' willingness to respond in an influenza pandemic. We thus propose using an EPPM-informed assessment of EMS workers' perspectives toward fulfilling their influenza pandemic response roles.Methodology/Principal FindingsWe administered an EPPM-informed snapshot survey about attitudes and beliefs toward pandemic influenza response, to a nationally representative, stratified random sample of 1,537 U.S. EMS workers from May\ue2\u20ac\u201cJune 2009 (overall response rate: 49%). Of the 586 respondents who met inclusion criteria (currently active EMS providers in primarily EMS response roles), 12% indicated they would not voluntarily report to duty in a pandemic influenza emergency if asked, 7% if required. A majority (52%) indicated their unwillingness to report to work if risk of disease transmission to family existed. Confidence in personal safety at work (OR\ue2\u20ac\u160=\ue2\u20ac\u1603.3) and a high threat/high efficacy (\ue2\u20ac\u153concerned and confident\ue2\u20ac?) EPPM profile (OR\ue2\u20ac\u160=\ue2\u20ac\u1604.7) distinguished those who were more likely to voluntarily report to duty. Although 96% of EMS workers indicated that they would probably or definitely report to work if they were guaranteed a pandemic influenza vaccine, only 59% had received an influenza immunization in the preceding 12 months.Conclusions/SignificanceEMS workers' response willingness gaps pose a substantial challenge to prehospital surge capacity in an influenza pandemic. \ue2\u20ac\u153Concerned and confident\ue2\u20ac? EMS workers are more than four times as likely to fulfill pandemic influenza response expectations. Confidence in workplace safety is a positively influential modifier of their response willingness. These findings can inform insights into interventions for enhancing EMS workers' willingness to respond in the face of a global infectious disease threat.104264/PHS HHS/United StatesP01TP00288-01/TP/OPHPR CDC HHS/United States20352050PMC284443

    Immune Protection Induced on Day 10 Following Administration of the 2009 A/H1N1 Pandemic Influenza Vaccine

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    BACKGROUND: The 2009 swine-origin influenza virus (S-OIV) H1N1 pandemic has caused more than 18,000 deaths worldwide. Vaccines against the 2009 A/H1N1 influenza virus are useful for preventing infection and controlling the pandemic. The kinetics of the immune response following vaccination with the 2009 A/H1N1 influenza vaccine need further investigation. METHODOLOGY/PRINCIPAL FINDINGS: 58 volunteers were vaccinated with a 2009 A/H1N1 pandemic influenza monovalent split-virus vaccine (15 µg, single-dose). The sera were collected before Day 0 (pre-vaccination) and on Days 3, 5, 10, 14, 21, 30, 45 and 60 post vaccination. Specific antibody responses induced by the vaccination were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). After administration of the 2009 A/H1N1 influenza vaccine, specific and protective antibody response with a major subtype of IgG was sufficiently developed as early as Day 10 (seroprotection rate: 93%). This specific antibody response could maintain for at least 60 days without significant reduction. Antibody response induced by the 2009 A/H1N1 influenza vaccine could not render protection against seasonal H1N1 influenza (seroconversion rate: 3% on Day 21). However, volunteers with higher pre-existing seasonal influenza antibody levels (pre-vaccination HI titer ≥1∶40, Group 1) more easily developed a strong antibody protection effect against the 2009 A/H1N1 influenza vaccine as compared with those showing lower pre-existing seasonal influenza antibody levels (pre-vaccination HI titer <1∶40, Group 2). The titer of the specific antibody against the 2009 A/H1N1 influenza was much higher in Group 1 (geometric mean titer: 146 on Day 21) than that in Group 2 (geometric mean titer: 70 on Day 21). CONCLUSIONS/SIGNIFICANCE: Recipients could gain sufficient protection as early as 10 days after vaccine administration. The protection could last at least 60 days. Individuals with a stronger pre-existing seasonal influenza antibody response may have a relatively higher potential for developing a stronger humoral immune response after vaccination with the 2009 A/H1N1 pandemic influenza vaccine
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