Chicken fingers pointing

A couple of days ago BirdLife International suggested avian influenza might be spread by using poultry manure as food in fish farms, something done routinely in Asia.

Known as integrated livestock-fish farming, the technique involves transferring the wastes from raising pigs, ducks or chickens directly to fish farms. At the right dosage, the nutrients in the manure give an enormous boost to the growth of plankton in the ponds, which are the main food of fish such as carp and tilapia.

BirdLife International is now calling for an investigation into the possibility that thousands of manure-fed ponds across Asia may be the means by which the new potentially deadly strain of avian influenza, H5N1, is being spread. BirdLife points out that outbreaks of H5N1 have occurred this year at locations in China, Romania and Croatia where there are fish farms. (The Independent)

This is a pretty interesting story, with intrigue and not very hidden agendas all over the place. The bird conservation community has been seriously exercised over the claim by WHO and the UN Food and Agriculture Organization (FAO) that wild migratory birds are vectors of bird flu, especially the H5N1 subtype. They fear (with some justification) that governments and localities will rashly carry out massacres of wild birds and try to deny them natural habitat. Even if these birds do carry the virus (and in our view it is likely they do), there is little anyone can do about it. You can't kill all wild birds nor would you want to. You could do a lot of environmental damage trying, however. So birders and ornithologists have been waging a full scale counter-attack on the notion, a counter-attack that often includes blanket denials that wild birds can be carriers.

The FAO, on the other hand, has been actively promoting integrated livestock-fish farming as a means to provide lower cost protein to the developing world. Another worthy idea. But the idea that virus contaminated poultry feces might be a source of contamination for wild birds and others makes both scientific and commonsense:

Although no mention has been made of the possible links between manure-fed ponds and influenza in the recent alarm over bird flu, the issue has been raised before, and the FAO, although actively promoting the technique, is well aware of the threat.

Its 2003 report, Integrated Livestock Fish Farming Systems, noted: "Recently, livestock and fish have been implicated in the irregular occurrence of influenza pandemics; the global impacts on public health of promoting livestock and fish integration are huge if these claims are substantiated."

In fact, the FAO may have been aware for very much longer that some scientists think there is a risk. The 2003 report includes a reference to a paper published in the journal Nature in 1988. This paper, by Christoph Scholtissek from the University of Giessen in Germany and Ernest Naylor from the University of Bangor in Wales, was titled Fish Farming and Influenza Pandemics. It said that bringing together fish farms with farm livestock "may well be the creation of a considerable human health hazard".

However, the FAO has continued to promoted integrated livestock fish farming actively throughout the ensuing period. (The Independent)

Now FAO is shooting back. Sort of. If you call being arrogantly dismissive, "shooting back." Their Chief Veterinary officer, Dr. Joseph Domenach told Reuters it was a "theoretical risk" but would only be a local problem for birds that used the contaminated pond. Adequate surveillance would take care of the problem, he said. As for wild birds:

"Today it's impossible to say that wild birds are not playing a role," said Domenech. "We hope in three to four months, at the end of this migration period, we will see better."

Of course what if they are both right: infected poultry feces are contaminating ponds where migratory birds drink and then spread it elsewhere. I don't think either side would be satisfied with that compromise because each blames the other as a means to protect its own concerns.

Ask Not for whom the Chicken Fingers point. They point for Thee.