[e-drug] Pandemic influenza: are we prepared?

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E-DRUG: Pandemic influenza: are we prepared?
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[copied as fair use; WB]

www.thelancet.com 

Pandemic influenza: are we prepared?
By Pamela Das (The Lancet Infectious Diseases) and Hannah Brown (The Lancet) 
14 October, 2005 
Copyright Guardian Newspapers Limited 2005

The deadly H5N1 avian influenza virus is hitting bird populations at Europe's easternmost borders just as new research has suggested that the virus could jump to humans more easily than was first thought. A reconstruction of the strain that caused the influenza pandemic of 1918, which killed around 50 million people, shows that it shares several characteristics with H5N1. These similarities put paid to the theory that the avian flu virus would have to mix with a human version to create a strain capable of sweeping through the human population. Instead, all that is needed is a few mutational changes in the avian virus' genome?and, worryingly, H5N1's global mobility makes this an immediate concern. 

But, unlike the surprise explosion of cases that marked the start of the three 20th century pandemics of 1918, 1957, and 1968, for H5N1, we have been warned in advance. The strain has been circulating among poultry populations in Southeast Asia since 2003 and its persistence has given the world time to prepare. Since 1999, the World Health Organization (WHO), based in Geneva, has been urging all countries to develop a pandemic contingency plan. Earlier this year, in response to pleas for help from countries with little knowledge of pandemic planning, WHO published detailed guidelines on appropriate strategies to adopt. Unfortunately, uptake of these recommendations has been worryingly slow. 

There are just 40-50 countries with preparedness plans in development. Some, such as the UK, the Netherlands, and Canada are fairly advanced, but no country is yet fully prepared. Others have no plans at all. Misplaced complacency about the immediacy of the threat is one factor causing countries to drag their heels, but difficulties securing resources and galvanizing political commitment are also to blame. Recent scares have prompted the UK, EU, and the USA to step up their activities. But in Asia and elsewhere, several countries are struggling to find the necessary cash. These nations need rich nations' help. 

But even if all countries heed WHO's guidance, there is no guarantee that the plans will prevent the pandemic's suffering and death. The necessary reliance on vaccines and antiviral drugs means the adequacy of emergency-response preparations cannot be guaranteed. Vaccines against H5N1 are in development now, but no one can predict whether they will match the strain that eventually breaks out. Drugs are effective if used promptly, but come in limited supplies. 23 countries have already ordered the antiviral drug oseltamivir for national stockpiles, but the main manufacturer of these medicines, Roche, will not be able to complete already-placed orders for at least another year (and that's without Turkey's new demand for 1 million boxes of the drug). Spare production capacity to cope with demand surges is worryingly small and the complexity of the drug-making process means that other manufacturers are in no position to help. The disturbing conclusion reached by WHO last month was this: ?On present trends, neither of these interventions [drugs nor vaccines] will be available in adequate quantities or equitably distributed at the start of a pandemic and for many months thereafter.? 

While individual nations have been preparing their plans, the international community has been working on a global response. Before now, no effort had ever been made to halt a pandemic by intervening at its source?but this is just what WHO plans to do. Thanks to a donation from Roche, there is now an international stockpile of 3 million treatment courses that will be used to suppress the first outbreak among humans. The success of this action depends on WHO receiving timely alerts about the first human cases; this means quick diagnosis, detection of case clusters, and communication of the information worldwide. But in the most risk-prone places, the surveillance system is weak. Many laboratories simply don't have the capability to make quick diagnoses, and widespread poverty in areas where a pandemic is most likely to emerge means there is little incentive for farmers (who are likely to be the first to develop signs of sickness) to report symptoms that could see their stocks of poultry culled. 

To help boost the international capacity for response?and to ensure countries with scant resources don't suffer disproportionately or endanger the world?last month WHO sent all health ministries a list of urgent activities that should be done now. These measures?which include setting up systems of quarantine, drug distribution, and disease monitoring, and improving worldwide communication between professionals in animal and human health?will improve early detection in countries where such systems are currently poor, and should boost international capabilities to act. 

But is this enough? The effective control of SARS in 2003 showed that global cooperation could effectively combat emerging diseases. But slow-spreading SARS is no model for rampant influenza. Fortunately, forewarned is forearmed. Our knowledge that a global pandemic will happen sometime soon offers an unprecedented opportunity to mitigate its effects. But success in this endeavor requires coordinated international activity now to strengthen early warning systems in vulnerable countries and, perhaps most importantly, to contain the current outbreaks in birds. Only by looking outside our borders will we protect ourselves. 

Resources: 

WHO checklist for preparedness planning
http://www.who.int/csr/resources/publications/influenza/ 
CDS_CSR_GIP_2005_4.pdf

WHO urgent strategic actions for avian influenza
http://www.who.int/csr/resources/publications/influenza/ 
WHO_CDS_CSR_GIP_05_8-EN.pdf