Transcript
Page 1: Bird flu fears heading west

Writer Aldous Huxley died onNovember 22, 1963, but nobodytook any notice, because this wasalso the day J.F. Kennedy wasshot dead. Similarly, the biggestinfluenza pandemic of the 20thcentury killed 20 million people in1918/19, but did not make the topheadlines, because there was aWorld War going on at the sametime. To this day, the diseasewrongly labelled the Spanish fluhas remained a footnote in thehistory books.

Recently, however, people havebeen paying somewhat moreattention to it. Today, we knowthat flu epidemics do not comefrom Spain, but that they arisewhen avian flu viruses cross thespecies barrier and by mutationacquire the ability not only toinfect humans but also to transmitthe infection directly from oneperson to another. The most likelybreeding place for new viruses ofthis kind is South East Asia, wheremillions of domestic birds andmany millions of people live inclose proximity.

In recent years, with human andbird populations continuing torise, this problem has become

more urgent. Since December2003, a number of regionaloutbreaks of the avian flu strainH5N1 in South East Asia havecaused serious economicdamage and led to over 100confirmed cases of humaninfection, resulting in over 50deaths. Earlier this year, thediscovery of infected wild birds inRussia, Kazakhstan and possiblyFinland suggested that theautumn migrations might spreadthe virus to Europe. In thiscontext, the European Union andits member states are faced withtwo important tasks: containingthe spread of influenza in birds toavoid economic damage to thepoultry industry, and even moreimportantly, making viable plansfor the day when bird flu turnsinto a human flu pandemic.

In order to protect the freerange chickens on Europeanfarms, one has to keep an eye onthe wildfowl. Many variants ofinfluenza virus are known to beless dangerous to wild waterfowlthan to farmyard turkeys andchickens. If this holds for thevariant H5N1, which caused therecent flu outbreaks in Asia, wildanimals could spread it to Europewithout suffering too much from itthemselves.

Following reports of a potentialcase of avian flu in a seagull inFinland, the Dutch agricultureminister ordered all free-rangechickens to be kept indoors untilfurther notice. However, other EU

member states have not followedthis stance, as the EU still — instatements issued August 25 —rates the risk of avian fluspreading to its area as ‘low’.Nevertheless, it has responded tothe possibility by boosting thebudget for a surveillance systemof migratory birds that has been inplace since 2003, providing anextra 2.4 million euros in order tomonitor the distribution ofpotentially dangerous viruses inthe wild.

The Commission has also askedthe member states for regularupdates via the Early Warning andResponse System (EWRS). OnSeptember 20th, the authoritiesinvolved in the EWRS are due tohold a meeting to deal with therisks of avian flu.

All these measures may or maynot protect European poultry fromthe disease and Europeanfarmers from economic losses,but they will do nothing to stopthe next human influenzapandemic. Experts agree that thisis most likely to arise from Asia,no matter how many ducks orchickens are infected in Europe.There are essentially two thingsthat need to be done to limit thedamage from a potential humanpandemic. Plan A involvesconfining the outbreak at itssource, and plan B needs to beprepared for the likely failure ofplan A.

Plan A suffers from all thepredictable problems. In countrieslike Vietnam, the lack of researchresources means that an outbreakwill be diagnosed too late, andthere won’t be the necessarymedical resources to contain it.While wealthier Asian nationssuch as Hong Kong havedemonstrated rapid and efficientresponse to outbreaks of avianflu, poorer nations remainvulnerable and will depend ontechnical and financial help forany measures to intercept apotential flu pandemic at source.The European Commission hasalready started providing suchhelp to some countries,particularly to Vietnam.

Such help and improvements ofthe situation in Asia may be ableto suppress some, perhaps evenmany, species crossings that

experiments must be replaced bymethods that do not use them, andthe number of animals in researchmust be reduced. “We wouldrather not use any animals and wetry hard to find alternatives,” saidgeneticist Robin Lovell-Badge, ofthe National Institute for MedicalResearch in London.

The statement also promises tobe more open about animalexperimentation, urging researchestablishments to “provide clearinformation and promote rationaldiscussion”. “We have seen amood of increased opennessamongst researchers over the last

two years,” said Festing. “We arebuilding on that and thedeclaration will help.”

The new legislation became lawearlier this year but has yet to befully tested. It aims to crack downon the intimidation of companiesinvolved in animalexperimentation, making it anoffence to protest outsideemployees’ homes. It also allowsactivists to be banned fromreturning to places with theintention of attempting to forcepeople to stop doing things —such as animal experimentation —which are allowed by law.

Current Biology Vol 15 No 18R740

Bird flu fears heading westThe spread of avian influenza forSouth East Asia to places asdistant as Russia and Finland hasprompted the European Union togear up its response amid thefears that it may spawn a newhuman influenza pandemic.Michael Gross reports.

Page 2: Bird flu fears heading west

otherwise might have led to apandemic but most experts agreethat one day, sooner or later, anew virus will emerge and causea new pandemic. If and when thathappens, and a human-to-humaninfection begins to spreadglobally, will the world beprepared?

In a word, no. Even thoughscientists today know so muchmore about influenza than theydid before the 1918 pandemic, anoutbreak starting today could turnout just as catastrophic, if notmore so. If matters stay as theyare, Michael Osterholm from theUniversity of Minnesota warns, we“will remain vulnerable to a globaleconomic disaster”.

Part of the problem is theremarkably high variability of fluvirus strains, which makes itnecessary that a new straindiscovered in humans becountered with a new vaccine.Developing this will take sixmonths, and even then theproduction using currentmethods (incubation of viruses in

eggs) will be so slow that only avery small fraction of the worldpopulation could ever beprotected.

Researchers hope that in thelong term they may be able todevelop generalized flu vaccinesbased on antigens found in mostflu viruses, and also to producevaccines in a more efficient andadaptable way. In the US, theNational Institutes of Health (NIH)at Bethesda, Maryland, is playinga pivotal role in these efforts,backed by a major sequencingeffort which has already broughtto book more than 100 humaninfluenza virus isolates. Theimproved vaccines, however, arestill a few years off, any hopeinvested in them depends on theassumption that we still have thatmuch time before the nextpandemic strikes.

Similarly, antiviral drugseffective against some flu strainsexist already, but researchersneed more time to developmedication that would be moregenerally useful and could be

made widely available in a shorttime. Furthermore, governmentsand international organisationsneed to work out detailedcontingency plans to avoid thatorganisation failures and panicreactions make things worse. Whoshould be vaccinated first, whichmovements should be restricted?Such questions have to beaddressed before the virusstrikes.

Considering this, the currentsemi-crisis in Asia may serve as auseful hint to researchers,governments, and internationalorganisations, reminding themthat the threat of a flu pandemicis real and that they need to actquickly to ensure that the nextcrossing over of avian flu intohumans doesn’t turn into a globalcatastrophe that makes all theheadlines.

Michael Gross is a science writer inresidence at the school ofcrystallography, Birkbeck College,University of London. He can becontacted via his web page atwww.proseandpassion.com

Magazine R741

Flying in: Concern is growing that the bird flu in South East Asia, now reported to be present on Europe’s eastern fringes, will movewest with the autumn migration of many species, raising fears about a spread to humans. (Picture: Photolibrary.com.)


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