France learns from chikungunya epidemic and moves to contain H5N1
France, the world's fourth largest exporter of poultry, has moved to vaccinate its poultry stocks to prevent the H5N1 'bird-flu' virus spreading from the confirmed cases in the south-west of the country. It will be the first country to do so on a national scale. Human H5N1 vaccines will shortly be available, and researchers, including those working on the EU funded Universal Vaccine project, are looking into the possibility of developing wide-ranging flu vaccines which could eliminate the disease. The French move to vaccinate its poultry comes at the same time as a pledge of 35 million euro for the French island territory of Réunion to alleviate the effects of the chikungunya epidemic, which has infected one-fifth of the local population. France has therefore seen what can happen during an epidemic, and wishes to make every effort to ensure that it and the rest of the world do not have to deal with an H5N1 epidemic. This could happen if the virus mutates and becomes transmissible between humans, but it is hoped that mass vaccination will alleviate the risk. 50 countries have sent representatives to the World Organisation for Animal Health in Paris to discuss H5N1 in the absence of verifiable information on how H5N1 spreads. Of the 35 million euro pledged to Réunion, a quarter of that money - 9 million euro - will be used to research the chikungunya virus, which has not previously been so virulent. Chikungunya is spread by mosquitoes, and symptoms include painful arthritis (from where it derives its name, coming from the Swahili words for a 'stooped walk'), a rash, fever and headache or photophobia. The virus is usually found in localised outbreaks in south-east Asia and Africa and is not usually fatal, although the very high rate of infection has resulted in 77 deaths linked either 'directly or indirectly' to the disease, according to the French government. The Réunion outbreak began a year ago and the disease spread steadily until late 2005, when the rate of transmission increased dramatically. More than 22,000 chikungunya infections were recorded in Réunion in the week to 17 February 2006. The disease has become so widespread in Réunion that tourists to the island have reported the disease on returning to France, with more than 30 cases at a single Paris hospital. Cases are also now increasing on islands nearby. The French Prime Minister, Dominique de Villepin, made the cash pledge to Réunion on a recent visit. 'We are totally committed to preventing [chikungunya], getting rid of mosquitoes and offer the medical services necessary to provide a solution for all those who are suffering,' he said. In the short term, dealing with chikungunya will be easy - 500 French troops have been deployed to destroy mosquito breeding grounds on the island, which will bring down the rates of infection. Back on the French mainland, H5N1 will not be so easily contained. The French poultry industry is worth an estimated 6 billion euro per year, and the French government has decided to vaccinate a million free-range ducks, chickens, geese and other birds in an attempt to stem the spread of H5N1. An average of 25,000 birds will be vaccinated daily, but several countries have already decided to ban French poultry. The French government came under intense criticism at home for the perceived slow response to the Chikungunya outbreak in Réunion, and is now taking no chances with the H5N1 virus. Poultry farmer Daniel Clair described has to Le Parisien how the H5N1 virus struck 'like lightning', with 400 turkeys perishing in one night. As Mr Clair's turkeys were held indoors, researchers believe that they may have been infected by excrement from wild ducks on their straw. If true, this is an indicator of just how contagious the H5N1 strain is. Recent developments include the first discovery of H5N1 in Sweden, and the finding of an infected dead cat on an island off the north German coast, where several wild birds were found to have contracted H5N1. This is not the first time the virus has been found to jump from a bird to a cat, and the WHO does not believe the jump is significant, but it is the first jump from bird to mammal recorded in Europe. In Africa, the virus has been confirmed amongst bird populations in Nigeria, Egypt and Niger, with unconfirmed cases in Ethiopia and Kenya. The method of transmission of H5N1 between birds is very poorly understood. 'We know next to nothing about this virus; we have only anecdotal information about where it exists and what birds it infects,' said Vittorio Guberti, an expert on avian flu from the Italian National Institute for Wildlife, speaking to the New York Times. 'We don't even know where to focus. We have to sit and wait for the big epidemic to occur, and in the meantime there will probably be small outbreaks all the time.' To coincide with the coming of spring, 'Two million ducks from Nigeria, where there is a big problem, will arrive in Italy. And we don't know a thing about them,' he said. Scientists in Hong Kong have studied the progression of the disease since its emergence in China's Guangdong province prior to 1997. They believe that the disease originated in domestic poultry, and spread via migrating wild ducks or geese. Recent tests on domestic and migrating wild birds in the west of China confirmed the same genetic type of H5N1 as in the first Guangdong cases. Many of these birds will now have migrated as far as Europe. 'For a couple of weeks, it was raining dead swans all over Europe, which left everyone scratching their heads,' commented Jan Slingenberg, at the UN Food and Agriculture Organization in Rome in an interview with the New York Times. 'Are the swans just the tip of the iceberg? Where should we worry? But given the rapid geographic spread in so many different places, it is a good idea for everyone to be stepping up security.' The H5N1 virus has been responsible for a total of 93 deaths from 173 confirmed cases since 1991. All these transmissions are thought to be from bird to human, and infected people have usually been living or working in close quarters with birds. However, the high rate of fatality (53.8 per cent) has prompted very close scrutiny of the spread of this strain. The EU approved the use of vaccination as a means to prevent the spread of H5N1 on 22 February. Experts fear that should a person already infected with 'seasonal' flu contract H5N1, the two viruses could combine and mutate to produce a strain as infectious and deadly as H5N1, but transmissible between humans. In the future, broad-range flu vaccines may be a possibility thanks to schemes like the EU-funded Universal Vaccine project. The name of the strain, H5N1, refers to protein types. There are 16 different H types and nine different N types, giving 144 unique virus types. Each vaccine would have to block those specific combinations. There is however a third protein group, known as M2, which researchers have found to be constant across flu types since its discovery in 1933. Vaccines targeting this group would be broad-spectrum. The research team from Belgium, Sweden, the Netherlands and the UK hopes to be able to move the vaccine to clinical trials by 2007. Successful vaccinations could protect individuals for life, potentially relegating flu to history in the same way as smallpox. The British Royal Society, the UK national academy of science, and the Academy of Medical Sciences have launched a study to 'provide a timely analysis of the underlying science of avian and pandemic influenza', according to chair, Sir John Skehel. The group will examine the latest scientific evidence in order to judge the best forms of treatment, clinical care and surveillance models should a pandemic occur. They will also take lessons from existing models of disease and public emergency as well as scientific knowledge and social factors to see how they will influence public policy and preparation in the event of an outbreak.
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