Pandemic Influenza Preparedness Plans Research Articles

Risk modelling the mortality impact of antimicrobial resistance in secondary pneumococcal pneumonia infections during the 2009 influenza pandemic

ObjectivesThe aim of this study was to estimate the impact of antimicrobial resistance (AMR) in secondary pneumococcal pneumonia infections on global mortality during the 2009 influenza pandemic, to estimate future pandemic mortality risk and to inform pandemic preparedness. MethodsRisk analysis modelling was conducted using a multivariate risk formula. Literature reviews were conducted to generate global central estimates for each of the parameters of the risk formula in relation to the 2009 influenza pandemic, secondary pneumococcal pneumonia, rates of AMR, and pneumococcal vaccine efficacy as a component of pandemic preparedness. ResultsGlobal Streptococcus pneumoniae AMR was estimated at 21.8% to 27.6%, and contributed to 1.8% to 2.3% of deaths during the 2009 influenza pandemic. When directly applied to mortality due to multidrug resistance, pneumococcal vaccination could potentially prevent 1277 to 3754 deaths and could have reduced mortality from multidrug-resistant S. pneumoniae to 1% to 1.2%. ConclusionsAMR in secondary pneumococcal infections contributed towards a small percentage of the global mortality during the 2009 influenza pandemic. Increased S. pneumoniae AMR could result in a three- to four-fold rise in mortality due to secondary pneumococcal infections in future influenza pandemics. Pneumococcal vaccination has an important role in preventing pneumococcal co-infections and combating AMR in all populations, and should be considered a key component of influenza pandemic preparedness or early action plans.

European Pandemic Influenza Preparedness Planning: A Review of National Plans, July 2016.

Pandemic influenza A (H1N1) commenced in April 2009. Robust planning and preparedness are needed to minimize the impact of a pandemic. This study aims to review if key elements of pandemic preparedness are included in national plans of European countries. Key elements were identified before and during the evaluations of the 2009 pandemic and are defined in this study by 42 items. These items are used to score a total of 28 publicly available national pandemic influenza plans. We found that plans published before the 2009 influenza pandemic score lower than plans published after the pandemic. Plans from countries with a small population size score significantly lower compared to national plans from countries with a big population (P <.05). We stress that the review of written plans does not reflect the actual preparedness level, as the level of preparedness entails much more than the existence of a plan. However, we do identify areas of improvement for the written plans, such as including aspects on the recovery and transition phase and several opportunities to improve coordination and communication, including a description of the handover of leadership from health to wider sector management and communication activities during the pre-pandemic phase. (Disaster Med Public Health Preparedness. 2019;13:582-592).

PanStop: a decade of rapid containment exercises for pandemic preparedness in the WHO Western Pacific Region.

Member States in the Western Pacific Region (WPR) of the World Health Organization (WHO), are highly vulnerable to emerging influenza viruses that have the potential to cause global pandemics. A well-coordinated strategy for preparedness is required at national and international levels for a robust response and to mitigate the potentially dire consequences of the next influenza pandemic. Of 37 countries and areas in the region, 23 have publically available national pandemic influenza preparedness and response plans; of these, only 17% have been updated in the last five years. However, many plans are pending update and may benefit from integrating some components of the 2017 WHO pandemic influenza risk management guide. Additionally, many plans need to be operationalized to test their functionality. Since 2007, WPRO has conducted annual PanStop exercises to test pandemic containment plans and RC mechanisms in a simulated environment that imitates pandemic events as they unfold. PanStop exercises provide an opportunity for countries to validate policies, protocols and procedures involved in implementing rapid containment (RC) operations, and to identify strengths and opportunities for improvement in planning activities for pandemic influenza. By participating in exercises such as PanStop and the annual regional International Health Regulation (IHR) Crystal Exercise, and subsequently adapting national preparedness plans based on exercise outcomes, WPR continues to improve readiness for the next influenza pandemic.

A review on the preparedness plans on influenza pandemics, by WHO and China: the current status and development

Every influenza pandemic in history would end up with disastrous outcomes on mankind, of which the most notorious one was the "Spanish flu" pandemic in 1918. In the past century, with advanced knowledge on influenza viruses, laboratory technologies and surveillance methods, human beings were not as helpless when facing the influenza pandemic. In order to control the outbreaks and reducing the negative impacts, programs as: setting up and improving the influenza pandemic preparedness and response plan were recognized as important issues on early detection or prompt warning of any influenza virus strain that might lead to potential pandemics. The scheduled and planned control measures towards the pandemic preparedness and response plan had been considered of key importance in mitigating the peak of pandemic or controlling the transmission of virus. Since the "1918 influenza pandemic" , we had reviewed the evolution and development of plans regarding the preparedness and response on influenza pandemic issued by both WHO and China. We also emphasized on the variety of strategies which were linked to the preparedness and response at different historical stages, to provide reference for the pandemic preparedness of the disease, in the future.

Canadian Pandemic Influenza Preparedness: Health sector planning guidance.

Pandemic preparedness requires a multifaceted approach with collaboration from all levels of government. The Canadian Pandemic Influenza Preparedness: Planning Guidance for the Health Sector (CPIP) is a guidance document that outlines key health sector preparedness activities designed to ensure Canada is ready to respond to the next influenza pandemic. This article outlines Canada's approach to pandemic influenza preparedness as described in the CPIP Main Body. Canada's pandemic influenza preparedness planning takes place within a network of legislated requirements and emergency frameworks at provincial/territorial, federal and international levels. The plan includes several guiding principles, including collaboration among governments and stakeholders, evidence-based decision-making, proportionality and flexibility in tailoring responses to the situation, the adoption of a precautionary approach, the use of established practices and systems and the explicit incorporation of ethical principles in all decisions and decision-making processes. The roles and responsibilities of the federal and provincial/territorial governments is identified and three planning tools are provided: planning assumptions rooted in evidence; multiple scenarios to support decision-making; and descriptive terms such as the start, peak and end of pandemic wave rather than phase terminology to provide triggers for action. Overall, the CPIP Main Body sets out a scalable, coordinated risk management approach to an influenza pandemic. This is an evergreen document that will be updated regularly.

A Qualitative Stakeholder Analysis of Avian Influenza Policy in Bangladesh

Avian influenza is a major animal and public health concern in Bangladesh. A decade after development and implementation of the first national avian influenza and human pandemic influenza preparedness and response plan in Bangladesh, a two-stage qualitative stakeholder analysis was performed in relation to the policy development process and the actual policy. This study specifically aimed to identify the future policy options to prevent and control avian influenza and other poultry-related zoonotic diseases in Bangladesh. It was recommended that the policy should be based on the One Health concept, be evidence-based, sustainable, reviewed and updated as necessary. The future policy environment that is suitable for developing and implementing these policies should take into account the following points: the need to formally engage multiple sectors, the need for clear and acceptable leadership, roles and responsibilities and the need for a common pool of resources and provision for transferring resources. Most of these recommendations are directed towards the Government of Bangladesh. However, other sectors, including research and poultry production stakeholders, also have a major role to play to inform policy making and actively participate in the multi-sectoral approach.

Distressed setting and profound challenges: Pandemic influenza preparedness plans in the Eastern Mediterranean Region.

Influenza pandemics are unpredictable and can have severe health and economic implications. Preparedness for pandemic influenza as advised by the World Health Organization (WHO) is key in minimizing the potential impacts. Pandemic Influenza Preparedness (PIP) Framework is a global public-private initiative to strengthen the preparedness. A total of 43 countries receive funds through Partnership Contribution (PC) component of PIP Framework to enhance preparedness; seven of these fall in the WHO's Eastern Mediterranean Region. We report findings of a desk review of preparedness plans of six such countries from the Region. The assessment was done using a standardized checklist containing five criteria and 68 indicators. The checklist was developed using the latest WHO guidelines, in consultation with influenza experts from the Region. The criteria included preparation, surveillance, prevention and containment, case investigation and treatment, and risk communication. Two evaluators independently examined and scored the plans. Pandemic preparedness plan of only one country scored above 70% on aggregate and above 50% on all individual criteria. Plans from rest of the countries scored below satisfactory on aggregate, as well as on individual preparedness criteria. Among the individual criteria, prevention and containment scored highest while case investigation and treatment, the lowest for majority of the countries. In general, surveillance also scored low while it was absent altogether, in one of the plans. This was a desk review of the plans and not the actual assessment of the influenza preparedness. Moreover, only plans of countries facilitated through funds provided under the PC implementation plan were included. The preparedness scores of majority of reviewed plans were not satisfactory. This warrants a larger study of a representative sample from the Region and also calls for immediate policy action to improve the pandemic influenza preparedness plans and thereby enhance pandemic preparedness in the Region.

The Disaster Preparedness Program: a new model for sustainable capacity building through civil-military collaboration

Abstract Background The Disaster Preparedness Program (DPP) is a partnership between The Center for Disaster and Humanitarian Assistance Medicine (CDHAM)—a part of the Uniformed Services University of the Health Sciences—and the United States Africa Command (USAFRICOM). The DPP aims to assist African partner nations to enhance their disaster preparedness and response capabilities. The programme takes a whole-of-government approach to disaster preparedness and response, with an emphasis on plan development and, in some cases, creation of an autonomous national disaster management agency. Methods The DPP worked with the Embassy and other US government stakeholders to identify key ministries involved in disaster preparedness. With DPP assistance, a technical team from the partner nation undertook a comprehensive assessment of their current disaster response capabilities. This information was used to construct a disaster management strategic work plan that identified specific gaps in disaster preparedness. A disaster simulation exercise was conducted with representatives from agencies and ministries involved in disaster response. They applied their existing structure, plans and resources to a scenario designed for their country by CDHAM in order to identify any additional shortfalls in the plan. The finalised work plan could then be used by the partner nation to prioritise and address immediate needs. Findings Since 2009, CDHAM has worked with 16 partner nations. Ten countries have developed national pandemic influenza preparedness and response plans. By December, 2014, one country had used this plan to prevent the spread of Ebola, one country adapted this plan to a whole-of-government Ebola response, and six others are currently in the process of adopting this approach. Eight African armies have drafted military support to civil authorities disaster contingency plans, and one army has used this approach with Ebola. Ten countries have developed disaster management strategic work plans and are currently conducting activities in partnership with the US State Partnership Program, USAFRICOM, the Defense Threat Reduction Agency and the World Bank to fill gaps in their national disaster preparedness. Interpretation Although the work with the DPP is expected to enhance partner nations' preparedness and response to disasters, measuring the outcomes of these projects may take several years. The next phase of the DPP will focus on sustained support to local programmes while working with them to assess improvements in their response capabilities. As a result of these successful partnerships, CDHAM is now also playing a major role in assisting west African partner nations with Ebola preparedness activities. Funding Initially provided through USAID, but funding is now provided through the Defense Security Cooperation Agency's Overseas Humanitarian, Disaster, and Civic Aid.

Employee influenza vaccination in residential care facilities

The organizational literature on infection control in residential care facilities is limited. Using a nationally representative dataset, we examined the organizational factors associated with implementing at least 1 influenza-related employee vaccination policy/program, as well as the effect of vaccination policies on health care worker (HCW) influenza vaccine uptake in residential care facilities. The study was a cross-sectional study using data from the 2010 National Survey of Residential Care Facilities. Multivariate logistic regression analysis was used to address the study's objectives. Facility size, director's educational attainment, and having a written influenza pandemic preparedness plan were significantly associated with the implementation of at least 1 influenza-related employee vaccination policy/program, after controlling for other facility-level factors. Recommending vaccination to employees, providing vaccination on site, providing vaccinations to employees at no cost, and requiring vaccination as a condition of employment were associated with higher employee influenza vaccination rates. Residential care facilities can improve vaccination rates among employees by adopting effective employee vaccination policies.

Going Viral

The objective of this study was to assess hospital and emergency department (ED) pediatric surge strategies utilized during the 2009 H1N1 influenza pandemic as well as compliance with national guidelines. Electronic survey was sent to a convenience sample of emergency physicians and nurses from US EDs with a pediatric volume of more than 10,000 annually. Survey questions assessed the participant's hospital baseline pandemic and surge preparedness, as well as strategies for ED surge and compliance with Centers for Disease Control and Prevention (CDC) guidelines for health care personal protection, patient testing, and treatment. The response rate was 54% (53/99). Preexisting pandemic influenza plans were absent in 44% of hospitals; however, 91% developed an influenza plan as a result of the pandemic. Twenty-four percent reported having a preexisting ED pandemic staffing model, and 36% had a preexisting alternate care site plan. Creation and/or modifications of existing plans for ED pandemic staffing (82%) and alternate care site plan (68%) were reported. Seventy-nine percent of institutions initially followed CDC guidelines for personal protection (use of N95 masks), of which 82% later revised their practices. Complete compliance with CDC guidelines was 60% for patient testing and 68% for patient treatment. Before the H1N1 pandemic, greater than 40% of the hospitals in our study did not have an influenza pandemic preparedness plan. Many had to modify their existing plans during the surge. Not all institutions fully complied with CDC guidelines. Data from this multicenter survey should assist clinical leaders to create more robust surge plans for children.

Public Health Crisis Preparedness and Response in Korea

Since the 2006 Pandemic Influenza Preparedness and Response Plan according to the World Health Organization’s recommendation, the Republic of Korea has prepared and periodically evaluated the plan to respond to various public health crises including pandemic influenza. Korea has stockpiled 13,000,000 doses of antiviral drugs covering 26% of the Korean population and runs 519 isolated beds in 16 medical institutions. The division of public health crisis response in Korea Centers for Disease Control and Prevention are in charge of responding to public health crises caused by emerging infectious diseases including severe acute respiratory syndrome, avian influenza human infection, and pandemic influenza. Its job description includes preparing for emerging infectious diseases, securing medical resources during a crisis, activating the emergency response during the crisis, and fortification of capabilities of public health personnel. It could evolve into a comprehensive national agency to deal with public health crisis based on the experience of previous national emerging infectious diseases.

Southeastern European Health Network (SEEHN) Communicable Diseases Surveillance: A Decade of Bridging Trust and Collaboration

The communicable disease threats and changes that began emerging in south-east Europe in the early 1990s – after a decade of war and while political and health systems region-wide were undergoing dramatic changes – demanded a novel approach to infectious disease surveillance. Specifically, they called for an approach that was focused on cross-border collaboration and aligned with European Union standards and requirements. Thus, the Southeastern European Health network (SEEHN) was established in 2001 as a cooperative effort among the governments of Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Moldova, Montenegro, Romania, Serbia, and the former Yugoslav Republic of Macedonia. In 2002, SEEHN initiated a communicable diseases project aimed at strengthening both national and regional surveillance systems with a focus on cross-border collaboration. Over time, SEEHN has nurtured growth of a regional fabric of SEE experts in communicable diseases surveillance and response who are able to discuss emerging issues and best practices at any time and without being constrained by the rigidity of traditional or existing systems. Main achievements to date include joint preparation of influenza pandemic preparedness plans at both national and regional levels and the introduction of molecular techniques into influenza surveillance laboratories region-wide. Here, we describe the history of the SEEHN communicable disease project; major activities and accomplishments; and future sustainability of the regional infectious disease surveillance network that has emerged and grown over the past decade.

Drivers and consequences of influenza antiviral resistant-strain emergence in a capacity-constrained pandemic response

Antiviral agents remain a key component of most pandemic influenza preparedness plans, but there is considerable uncertainty regarding their optimal use. In particular, concerns exist regarding the likelihood of wide-scale distribution to select for drug-resistant variants. We used a model that considers the influence of logistical constraints on diagnosis and drug delivery to consider achievable ‘reach’ of alternative antiviral intervention strategies targeted at cases of varying severity, with or without pre-exposure prophylaxis of contacts. To identify key drivers of epidemic mitigation and resistance emergence, we used Latin hypercube sampling to explore plausible ranges of parameters describing characteristics of wild type and resistant viruses, along with intervention efficacy, target coverage and distribution capacity. Within our model framework, ‘real world’ constraints substantially reduced achievable drug coverage below stated targets as the epidemic progressed. In consequence, predictions of both intervention impact and selection for resistance were more modest than earlier work that did not consider such limitations. Definitive containment of transmission was unlikely but, where observed, achieved through early liberal post-exposure prophylaxis of known contacts of treated cases. Predictors of resistant strain dominance were high intrinsic fitness relative to the wild type virus, and early emergence in the course of the epidemic into a largely susceptible population, even when drug use was restricted to severe case treatment. Our work demonstrates the importance of consideration of ‘real world’ constraints in scenario analysis modeling, and highlights the utility of models to guide surveillance activities in preparedness and response.

Modeling rapidly disseminating infectious disease during mass gatherings

We discuss models for rapidly disseminating infectious diseases during mass gatherings (MGs), using influenza as a case study. Recent innovations in modeling and forecasting influenza transmission dynamics at local, regional, and global scales have made influenza a particularly attractive model scenario for MG. We discuss the behavioral, medical, and population factors for modeling MG disease transmission, review existing model formulations, and highlight key data and modeling gaps related to modeling MG disease transmission. We argue that the proposed improvements will help integrate infectious-disease models in MG health contingency plans in the near future, echoing modeling efforts that have helped shape influenza pandemic preparedness plans in recent years.

Push needed for pandemic planning

Three years after the H1N1 influenza pandemic, there is a reluctance to talk about it--even among health officials--as, despite widespread alarm, it was far less devastating than the 1918 Spanish flu. Pandemic fatigue has set in and is difficult to overcome in the current economic crisis. It's vital for the global health community to take in what happened during the 2009 outbreak and learn from says Dr Nahoko Shindo from the World Health Organization's (WHO) Global Influenza Programme. She warns that if this is not done soon, countries will lose momentum and the memory of what happened will fade. We need to fix the things that didn't work so that we can tackle similar threats better in future. Top on her list is the fact that, during the early phase of the 2009 pandemic, some countries were following their national guidance based on an older version of WHO pandemic preparedness guidance while WHO was following the updated version. In addition, she cites the fact that vaccines arrived in many countries after their first waves of the pandemic were over. Health authorities were criticized for calling for large sums to be spent on vaccines and antivirals at the time yet, in retrospect, available data show that antivirals helped to save lives and that vaccines were effective in immunizing populations, Shindo says. [ILLUSTRATION OMITTED] In mobilizing against H1N1 in 2009, WHO dispatched three million oseltamivir treatments to 72 countries in two weeks. Diagnostic kits were sent to 140 countries. Over the course of a year more than 78 million doses of a new vaccine went to 77 countries. The process of revising WHO pandemic preparedness guidance in line with lessons from the 2009 H1N1 pandemic started this year and involves consultation with WHO's 194 Member States. Initially the Organization will report progress on this to countries at the Executive Board meeting in January next year and then at the World Health Assembly in May. Shindo says that the revised guidance is likely to retain the whole-of-society approach involving all sectors, but that two components could be treated differently: the severity of the pandemic and the phases of the pandemic, a system used to determine all aspects of the response. Still, she adds, given the confusion over these elements, the revision process is far from over. These and other elements could change. Yet such guidance on pandemic influenza preparedness is important. Low- and middle-income countries, in particular, rely on it, while many high-income countries tend to make their own plans. An influenza pandemic is a global event and, therefore, when revising WHO guidance it is important to have countries' agreement on the concept of 'phases', 'severity' and other terminology, Shindo says. The challenges for health authorities preparing for the next pandemic are numerous so solid guidance is essential. Why plan for flu outbreaks and spend money to stockpile resources that may never be used? How should health authorities respond to an evolving health threat when national budgets are tight? And, in future, how should they communicate uncertainty in a fast-moving situation that is emotionally and politically charged? People are scared in outbreaks because the source of the fear is invisible, Shindo explains. They get angry too because outbreaks expose the weaknesses of their health systems, putting these systems under immense strain and then people suffer as a result. A WHO study released in 2011, Comparative analysis of national pandemic influenza preparedness plans, shows that more than 100 countries had such plans in 2009. Some plans have since been revised in light of the 2009 experience, but others are left as they were in 2009. And even where countries have plans, many are just on paper, they have never been tested in a desktop exercise, simulation or drill, Shindo says. …

Pandemic influenza preparedness: Africa at the crossroads

At least two distinct approaches to pandemic preparedness have arisen in response to the threats posed by pandemic influenza: a traditional public health approach and an increasingly securitised one. Traditional public health focuses on the population and their living conditions. In contrast, public health strategies informed by concerns with security focus on the resilience of critical infrastructure, such as electricity and communication, and on the ensuring good connections between different layers of government and any private bodies likely to be central to the response. Pandemic plans can be informed by one or a mix of both approaches. The securitised approach is more prevalent in the World Health Organization (WHO)’s plans and Western countries’ plans. In contrast, the WHO-AFRO Regional Pandemic Influenza Preparedness Plan 2009 utilises the existing Integrated Diseases Surveillance and Response framework as its starting point. It is informed by both rationales. Will African preparedness efforts develop in the direction of those already more informed by concerns about security? This paper examines how a securitised approach glosses over the differences between existing and threatened diseases. This is a particular problem in the African context with a high burden of infectious disease and underfunded health systems. Rather than a diversion of resources into a securitised approach, we suggest that the preparedness needs of the African continent are best served by focussing political will, international aid, financial and technical resources on the development of the health sector, including the integrated diseases surveillance and response framework. By tracing the distinct rationales at work in preparedness plans, it becomes apparent that an emphasis on the population will better position the continent for the future pandemics.

Original Article .The Optimal Allocation of Investment between Antivirals and Vaccines for Influenza Pandemic Preparedness Planning

Abstract Objectives To investigate that given a fixed amount of financial resources, what is the optimal combination of vaccine and antiviral stockpiles in terms of minimizing the attack rate. Methods Mathematic modeling was used to simulate the dynamics that with fixed influenza pandemic budget. Different budget conditions were observed if the combination changed. Framework between vaccines and antivirals was introduced by taking into account the uncertainty in vaccine and antiviral efficacy. Results Given a fixed budget, different budget allocations between vaccines and antivirals stockpile gave different attack rates. When the price of vaccine was lower than or similar with the antivirals, the attack rate increased with increasing investment in antiviral. But if the price of the vaccine was higher than the antivirals, the attack rate may not decrease with increasing investment in vaccine. Fixed the vaccine effectiveness, higher effectiveness of antiviral got a lower attack rate.When both antiviral and vaccine were with 50% probability of effectiveness, the attack rate changed by antiviral stockpile with a same pattern as they were with 100% efficacy probability, even it has a higher attack rate. Conclusions Assume the antivirals have 100% probability to be effective, budget was limited to a fix number, then in any event, population should stockpile a small amount of antivirals such that if the post-vaccination reproductive number turns out to be near 1, the additional intervention may further reduce the reproductive number to <1 and prevent the epidemic. Under the fixed budget, the price of the vaccines and antivirals will strongly affect the strategy of the stockpile allocation. When the price of vaccine is comparative lower, more investment of vaccine is better for the pandemic control, but if the vaccine price is too high then more investment in antiviral may be better. We found that attack rates and the optimal budget allocation depend on the probability to be effective of vaccine and antivirals.

A/H5N1 Prepandemic Influenza Vaccine (Whole Virion, Vero Cell-Derived, Inactivated) [Vepacel®

The influenza A subtype H5N1 virus is a likely causative agent for the next human influenza pandemic. Pandemic influenza vaccine production can begin only after a novel pandemic virus emerges. Cell-based vaccine production has advantages over conventional egg-based methods, allowing more rapid large-scale vaccine production. A reliable Vero cell culture system is available for pandemic and prepandemic influenza vaccine production. Prepandemic influenza vaccines are an important component of influenza pandemic preparedness plans, as their targeted use in the pandemic alert period or early in a pandemic is likely to mitigate the consequences of an influenza outbreak. Vepacel® is a prepandemic influenza vaccine (whole virion, Vero cell-derived, inactivated) containing antigen of H5N1 strain A/Vietnam/1203/2004 and is approved for use in the EU. Clinical immunogenicity studies with the vaccine have demonstrated good rates of functional neutralizing antibody responses against the vaccine strain (A/Vietnam/1203/2004), meeting established immunogenicity criteria for seasonal influenza vaccines, and cross-reactivity against H5N1 strains from other clades. In phase I/II and III studies, a heterologous (A/Indonesia/05/2005) booster vaccine administered to healthy adult and elderly volunteers 6-24 months after the two-dose priming vaccine (A/Vietnam/1203/2004) regimen induced good immunogenic responses against both H5N1 strains, demonstrating strong immunological memory. Broadly similar, albeit less robust, responses were observed in two special risk cohorts of immunocompromised and chronically ill patients. In general, adverse events observed in clinical immunogenicity studies with H5N1 vaccine (A/Vietnam/1203/2004) were similar to those reported with non-adjuvanted, inactivated, seasonal influenza vaccines.

Pandemic influenza preparedness planning: lessons from Cambodia.

aCommunicable Disease Policy Research Group, London School of Hygiene and Tropical Medicine, Bangkok, Thailand. bDepartment of Communicable Disease Control, Ministry of Health, Phnom Penh, Cambodia. cSaw Swee Hock School of Public Health, National University of Singapore, Singapore. Correspondence to Anthony C Huszar (e-mail: anthony@cdprg.org) Introduction Experts have estimated that a pandemic influenza outbreak could cost more than 60 million lives worldwide.1 When considered in combination with recent research demonstrating human-to-human transmission potential of the highly pathogenic strain of avian influenza A(H5N1),2 this highlights the growing need for public health officials to review their pandemic influenza preparedness strategy. This is especially true for SouthEast Asia which is predicted to be the likely epicentre of future pandemics.3

Oseltamivir (Tamiflu®) in the environment, resistance development in influenza A viruses of dabbling ducks and the risk of transmission of an oseltamivir-resistant virus to humans – a review

The antiviral drug oseltamivir (Tamiflu®) is a cornerstone in influenza pandemic preparedness plans worldwide. However, resistance to the drug is a growing concern. The active metabolite oseltamivir carboxylate (OC) is not degraded in surface water or sewage treatment plants and has been detected in river water during seasonal influenza outbreaks. The natural influenza reservoir, dabbling ducks, can thus be exposed to OC in aquatic environments. Environmental-like levels of OC induce resistance development in influenza A/H1N1 virus in mallards. There is a risk of resistance accumulation in influenza viruses circulating among wild birds when oseltamivir is used extensively. By reassortment or direct transmission, oseltamivir resistance can be transmitted to humans potentially causing a resistant pandemic or human-adapted highly-pathogenic avian influenza virus. There is a need for more research on resistance development in the natural influenza reservoir and for a prudent use of antivirals.