Influenza a (H1N1) outbreak and challenges for pharmacotherapy

Influenza A (H1N1) virus, a genetic reassortment of endemic strain of human, avian flu and swine flu, with an inherent ability to mutate continuously has developed a subtype which is causing present flu in humans. As on 10th May, 2009, twenty nine countries are affected with officially reported 4379 cases with Mexico--1626 affected (45 deaths), US 2254 affected (02 deaths); Canada 280 (01 deaths) and Costa Ricia -8 cases (01 death) respectively. Rest of 15 countries have reported less than 100 officially confirmed cases of H1N1 infection. WHO has already declared Pandemic Alert V on 29th April, 2009. If the present flu achieves equivalent virulence to that of 1918-19 pandemic flu, expected deaths will be 62 million people. Travel advisory, stockpiling of antiviral drugs--Tamiflu & Relenza; vaccine development, activation of business continuity planning for maintenance of essential serives etc., are some of the important mitigation approaches, being followed all over the world. WHO has a regional reserve of 10,000 million doses of anti-viral drugs. National Disaster Management Authority (NDMA), Government of India, an apex body for disaster management, in active coordination with Ministry of Health & other stakeholders/service providers is maintaining a constant state of vigil on the present Influenza A (H1N1) outbreak. In collaboration with UNDMT, NDMA has outlined a strategy for Pandemic Preparedness beyond Health in April, 2008. Various non-pharmaceutical interventions like detection, isolation and quarantine are required to contain the situation. Accordingly, stockpiling of 10 million doses of anti viral drugs, surveillance at airports, isolation with strict enforcement of quarantine procedures, sustained supply of respiratory masks & other personal protective equipment; deployment of rapid response teams are some of the activities being undertaken by Indian Government proactively. As situation goes to Phase VI, there will be a shift in strategy from active surveillance, detection and quarantine to containment, treatment, prevention of spread of disease and maintenance of business continuity beyond health sectors. The major concern is to utilise this latency period, between phase V and VI, to fill the gaps in state of preparedness. It is also essential to focus on development/procurement of appropriate vaccine to manage the situation arising from any further mutation of the existing causative virus to be resistant against existing anti viral therapies. It is a continued effort which can save many lives around the world and everyone has to play its assigned role effectively.

Meeting the challenge of influenza pandemic preparedness in developing countries

Developing countries face unique difficulties preparing for an influenza pandemic. Our current top-down approach will not provide these countries with adequate supplies of vaccines and antiviral agents. Consequently, they will have to use a bottom-up approach based on inexpensive generic agents that either modify the host response to influenza virus or act as antiviral agents. Several of these agents have shown promise, and many are currently produced in developing countries. Investigators must primarily identify agents for managing infection in populations and not simply seek explanations for how they work. They must determine in which countries these agents are produced and define patterns of distribution and costs. Because prepandemic research cannot establish whether these agents will be effective in a pandemic, randomized controlled trials must begin immediately after a new pandemic virus has emerged. Without this research, industrialized and developing countries could face an unprecedented health crisis.

Pandemic influenza: is there a corporate duty to prepare?

This article considers whether in the wake of an influenza pandemic companies may be exposed to claims of legal liability for failing to provide employees with access to antiviral medications, as the Department of Health and Human Services (HHS) now encourages businesses to do. It begins by describing influenza and influenza pandemics. It then discusses the benefits and limitations of antiviral therapies and the recent creation of antiviral option programs. It concludes by considering whether claims may be brought on the theory that corporate leadership is under a duty to prepare for a pandemic by considering whether to provide access to antiviral protection for employees.

Antiviral treatment for the control of pandemic influenza: some logistical constraints

Disease control programmes for an influenza pandemic will rely initially on the deployment of antiviral drugs such as Tamiflu, until a vaccine becomes available. However, such control programmes may be severely hampered by logistical constraints such as a finite stockpile of drugs and a limit on the distribution rate. We study the effects of such constraints using a compartmental modelling approach. We find that the most aggressive possible antiviral programme minimizes the final epidemic size, even if this should lead to premature stockpile run-out. Moreover, if the basic reproductive number R(0) is not too high, such a policy can avoid run-out altogether. However, where run-out would occur, such benefits must be weighed against the possibility of a higher epidemic peak than if a more conservative policy were followed. Where there is a maximum number of treatment courses that can be dispensed per day, reflecting a manpower limit on antiviral distribution, our results suggest that such a constraint is unlikely to have a significant impact (i.e. increasing the final epidemic size by more than 10%), as long as drug courses sufficient to treat at least 6% of the population can be dispensed per day.

Cost-effectiveness of antiviral stockpiling and near-patient testing for potential influenza pandemic

A decision analytical model was developed to investigate the cost-effectiveness of stockpiling antiviral (AV) drugs for a potential influenza pandemic in the United Kingdom and the possible role of near-patient testing in conserving AV drug stocks. Under base-case assumptions (including a fixed stockpile that was smaller than the clinical attack rate), the treat-only option (treating all symptomatic patients with AV drugs) would be considered cost-effective ( pound1,900- pound13,700 per quality-adjusted life year [QALY] gained, depending on the fatality scenario), compared with no intervention (nonintervention but management of cases as they arise). The test-treat option (testing all symptomatic patients but treating those with positive tests results only) would result in moderate gains in QALYs over the treat-only option but at relatively large additional costs. Stockpiling sufficient AV drugs (but not near-patient tests) to treat all patients with clinical cases would be cost-effective, provided AV drugs are effective at preventing deaths from pandemic influenza.

[The use of anti-viral agents in pandemic influenza, Icelandic guidelines]

Intensive work on preparedness planning for the next pandemic influenza is currently ongoing in Iceland as well as in other countries. Anti-viral agents will play a significant role in minimizing the potential devastating effects of pandemic influenza. In this overview the antivirals likely to be used in the next pandemic influenza are discussed and official national guidelines provided regarding their use. In order to maximize the utilization of the national stockpiles of antiviral agents the authors hope that icelandic physicians will follow the guidelines presented.

Business continuity management and pandemic influenza

Pandemic influenza planning presents challenges for both government and businesses. Effective cooperation and communication before and during a pandemic will help mitigate the major threats to societal function. The major challenges for government include communicating a realistic estimate of pandemic risk, managing community anxiety, communicating the need for rationing of vaccines and antiviral medications, setting standards for preparedness, and gaining the trust of essential service workers. For businesses the challenges are tailoring generic planning guides to local use, and making links with local and regional partners in pandemic planning.

Seasonal and pandemic influenza: recommendations for preparedness in the United States

There is a continued need to improve the state of preparedness for a potential influenza pandemic in the United States despite the publication of a pandemic influenza plan by the Department of Health and Human Services. Of particular importance are the sense of urgency for a coordinated response plan, an allocation of adequate funds to deal with this issue, and the need for a national leader to coordinate the development and execution of a national plan, including its relationship to the control of seasonal influenza. In addition, an infrastructure needs to be established in the United States to enable the rapid development and large-scale production of a safe and effective vaccine for new influenza strains; methods to treat influenza pneumonia need to be evaluated; a coordinated public health response needs to be defined; a nationally developed blueprint to deal with logistics of pandemic prevention is required; and there is a need to establish reliable communication systems on a national and local basis, to provide accurate information to the lay public, health care workers, and the agricultural sector.

Public health responses to influenza in care homes: a questionnaire-based study of local Health Protection Units

BACKGROUND

Influenza virus infection poses a major threat to the elderly people in residential care. We sought to describe the extent to which local public health services in England were positioned to detect and respond effectively to influenza-like illness (ILI) in nursing homes.

METHODS

A questionnaire-based survey was conducted in all 34 Health Protection Units (HPUs) regarding the 2004-05 influenza season.

RESULTS

Of the 20 responses, half reported 24 outbreaks of ILI in care homes. The mean resident population attack rate was 41% (range 15-79) with 31 deaths. Staff ILI occurred in 23 of 24 outbreaks. Seven of 20 HPUs stated that a local policy for the management of ILI in nursing homes was in place, with only four specifying the use of neuraminidase inhibitors (NI) for treatment of cases and prophylaxis of residents. In the outbreaks reported, NIs were used for treatment and prophylaxis, respectively, in only 46 and 54% of instances.

CONCLUSIONS

Given the availability of effective interventions for treatment and prophylaxis, there is potential to prevent substantial morbidity and mortality from influenza in at-risk populations. This study suggests that challenges remain in the effective response to influenza outbreaks in care homes and that there are wide variations in practice at local level.

Chronic hepatitis C

Antiviral therapy is approved by NICE but too few patients receive it

Pandemic unpreparedness?

Analysis of national influenza pandemic preparedness plans reveals that the preparations for an effective response in the early stages of a pandemic, while a vaccine is still being prepared, are giving cause for concern.

Modeling the worldwide spread of pandemic influenza: baseline case and containment interventions

BACKGROUND

The highly pathogenic H5N1 avian influenza virus, which is now widespread in Southeast Asia and which diffused recently in some areas of the Balkans region and Western Europe, has raised a public alert toward the potential occurrence of a new severe influenza pandemic. Here we study the worldwide spread of a pandemic and its possible containment at a global level taking into account all available information on air travel.

METHODS AND FINDINGS

We studied a metapopulation stochastic epidemic model on a global scale that considers airline travel flow data among urban areas. We provided a temporal and spatial evolution of the pandemic with a sensitivity analysis of different levels of infectiousness of the virus and initial outbreak conditions (both geographical and seasonal). For each spreading scenario we provided the timeline and the geographical impact of the pandemic in 3,100 urban areas, located in 220 different countries. We compared the baseline cases with different containment strategies, including travel restrictions and the therapeutic use of antiviral (AV) drugs. We investigated the effect of the use of AV drugs in the event that therapeutic protocols can be carried out with maximal coverage for the populations in all countries. In view of the wide diversity of AV stockpiles in different regions of the world, we also studied scenarios in which only a limited number of countries are prepared (i.e., have considerable AV supplies). In particular, we compared different plans in which, on the one hand, only prepared and wealthy countries benefit from large AV resources, with, on the other hand, cooperative containment scenarios in which countries with large AV stockpiles make a small portion of their supplies available worldwide.

CONCLUSIONS

We show that the inclusion of air transportation is crucial in the assessment of the occurrence probability of global outbreaks. The large-scale therapeutic usage of AV drugs in all hit countries would be able to mitigate a pandemic effect with a reproductive rate as high as 1.9 during the first year; with AV supply use sufficient to treat approximately 2% to 6% of the population, in conjunction with efficient case detection and timely drug distribution. For highly contagious viruses (i.e., a reproductive rate as high as 2.3), even the unrealistic use of supplies corresponding to the treatment of approximately 20% of the population leaves 30%-50% of the population infected. In the case of limited AV supplies and pandemics with a reproductive rate as high as 1.9, we demonstrate that the more cooperative the strategy, the more effective are the containment results in all regions of the world, including those countries that made part of their resources available for global use.

Will they deliver treatment access?: WTO rules and Canada's law on generic medicine exports

More than two years since Canada enacted the Jean Chrétien Pledge to Africa, no generic medication produced under compulsory license has yet been exported from Canada. In this feature article, Richard Elliott describes attempts by two Canadian generic pharmaceutical companies to navigate the complicated and unwieldy processes established under the Act, and, noting the government's pledge to review the law and fix it to make it work, prescribes a number of ways in which the process should be streamlined.