According to experts, wild birds are spreading the deadly H5N1 virus that’s wiping out poultry worldwide. But are they really to blame? Or is the disease not only a direct result of intensive farming – but actually being spread by the industry? Joanna Blythman reports Wednesday June 7, 2006 The Guardian If you normally make a point of buying free-range poultry and eggs, then you may be wondering if this is any longer a wise decision. The television reportage of bird flu, with its shots of men wearing white suits and masks chasing chickens in poor, rural Asian or African villages, or footage of chickens being slaughtered in third world markets while sinister-looking, positively Hitchcockian wild birds circle overhead, has helped build the perception that H5N1 is a disease of wild birds and domesticated poultry kept outdoors in primitive – and, by implication, dodgy – circumstances. On the home front, the nation is on amber alert.

All the major summer agricultural shows have decided to abandon their customary displays of live poultry. The fear is that H5N1 is winging its way to Britain, and that if we don’t get every last chicken, hen and budgie indoors, then it could mutate into a human flu pandemic and any minute we’ll be dead. A stream of statements and strategy documents from august bodies such as the World Health Organisation reinforce the "wild birds and backyard poultry are the problem" plot-line. This must come as music to the ears of the intensive poultry producers, who heartily resent the good press that organic and free-range poultry generally receive. For once it is free-range birds that everyone is worried about, not the caged laying hens and tightly packed broiler birds that generally feature in food exposes. But what if those august bodies have got it wrong? Multiple cracks are beginning to show in the supposed scientific consensus on the origins of avian flu.

A growing number of non-governmental organisations, bird experts and independent vets are pointing the finger at the global intensive poultry industry. A new report from Grain, an international environmental organisation, challenges the official line. "H5N1 is essentially a problem of industrial poultry practices," it says. "Its epicentre is the factory farms of China and south-east Asia. Although wild birds can carry the disease, at least for short distances, [the main infection] route is the highly self-regulated transnational poultry industry, which sends its products and wastes around the world through a multitude of channels." Grain’s alternative theory for the emergence of H5N1 – which got backing in an editorial in the Lancet medical journal last month – starts with the observation that bird flu has coexisted pretty peacefully with wild birds, small-scale poultry farming and live markets for centuries without evolving into a more dangerous form of the disease. An explanation for this is that outdoor poultry flocks tend to be low-density, localised, and offer plenty of genetic diversity in breeding stock.

By contrast, the hi-tech, intensive poultry farm, where as many as 40,000 birds can be kept in one shed and reared entirely indoors without ever seeing the light of day, is just like an overcrowded nursery of wheezy toddlers when the latest winter bug comes knocking – an ideal environment for spreading the disease and for encouraging the rapid mutation of a mild virus into a more pathogenic and highly transmissible strain, such as H5N1.

"What we are saying is that H5N1 is a poultry virus killing wild birds, not the other way around," says Devlin Kuyek, from Grain. The organisation’s view is supported by the charity BirdLife International, which plots the migratory routes of wild birds. "With few exceptions, there is a limited correlation between the pattern and timing of spread among domestic birds and wild bird migrations," it says. It points out that most of the bird flu outbreaks in south-east Asian countries can be linked to the movements of poultry and poultry products. Looking at the outbreaks in Nigeria and Egypt, which occurred almost simultaneously in multiple large-scale poultry operations, it says that there is "strong circumstantial evidence" that it was the transfer of infected material – straw, soil on vehicles, clothes or shoes – from one factory unit to another that spread H5N1 there, not wild birds. … Intense debate has built up over one particular mass outbreak last year among geese at Qinghai lake in northern China.

The widely accepted official explanation is that migratory birds carried the virus westwards from there to Russia and Turkey. But according to BirdLife International’s Dr Richard Thomas, no species migrates from Qinghai west to eastern Europe. "The pattern of outbreaks follows major road and rail routes, not flyways," he says. What Qinghai lake does have, however, is many surrounding intensive poultry farms whose "poultry manure", a euphemism for what is scraped off the floor of factory farms – bird faeces, feathers and soiled litter – is used as feed and fertiliser in fish farms and fields around Qinghai.

According to WHO, bird flu can survive in bird faeces for up to 35 days. Might it be that at Qinghai, H5N1 was passed from intensively reared birds to wild ones via chicken faeces, and not the other way around? … When H5N1 turned up in a remote village in eastern Turkey in January, this was initially blamed on migratory birds. Then when villagers gave their side of the story, it emerged that their diseased birds were intimately connected with a large factory farm nearby.

The UN’s Food and Agriculture Organisation (FAO) has now acknowledged that the poultry trade spread H5N1 in Turkey, singling out the common practice of intensive poultry farms sending out huge truckloads of low-value (possibly ailing) birds to poor farmers. Yet when bird flu hit a factory farm in Nigeria in February, the FAO spokesman still insisted: "If it’s not wild birds [that are the cause], it will be difficult to understand."

The Nigerian authorities, on the other hand, blamed the poultry industry. It subsequently emerged that the hatching eggs used by the farm in question were not from registered hatcheries, and may have come from a bird flu-infected country, such as Turkey. Worldwide, intensive poultry production has exploded and this growth seems to be mirrored by an increase in avian flu. … Joanna Blythman’s new book, Bad Food Britain – How A Nation Ruined Its Appetite, is published by Fourth Estate, price £7.99.

So who’s really to blame for bird flu?