Dr Ruth Watkins BSc Hons, BFA Oxon, MBBS, MSc, MRCP, MRCPath
A different strategy for bird flu in Turkey- VACCINATIONTurkey has been more open about bird flu than other SE Asian countries and China in which the virus appears to be endemic. There are very important advantages to us all in this.
It may be that WHO will be able to conduct valuable sero-epidemiology. By examining serum samples for antibody to H5N1 from a large number of families and villagers an accurate picture of who was or was not infected is gained. The morbidity and mortality of infection with H5N1 in humans can be more accurately known than the present clinical estimate of about 50% mortality. Questioning people about a flu-like illness coincident with handling poultry does not provide accurate information on H5N1 infection. In fact the widespread human infection in Turkey has alerted epidemiologists to the likelihood that infection has been more widespread in SE Asia and China than known hitherto, and there have been no large scale sero- epidemiology studies.
The openness may have had other distinct benefits such as the early administration of anti-virals to those suspected of having bird flu before laboratory confirmation is available and before they develop pneumonia- perhaps severe disease and mortality will be reduced. More samples will be taken during the epidemic and the course of human clinical disease and these will be promptly and widely available for detailed study and verification by specialist laboratories. Continuing studies on H5N1 infection and follow-up in infected areas, including wild bird and domestic bird sampling will add to the understanding of this epizootic.
Whilst Turkey is optimistic about clearing H5N1 infection from its country WHO is not. This is based on experience in SE Asia and China where this extraordinary highly pathogenic H5N1 strain has persisted and recurred for years.
Unlike in Western Europe there are many poor people in Turkey who are subsistence farmers or who live on the margins of malnutrition. What are they to do without any poultry? When are they to be allowed to restock? How can they ensure the virus will not return? Is there any exit strategy for this epidemic? For these people poultry, with their eggs, occasional meat and value for trade, must constitute a vital element in their nutrition, particularly for growing children. The essential amino acids in eggs are the best balanced for humans of any protein. Chickens lay even in winter.
There is no proof that the infection arrived in Turkey by wild birds, this is just glib talk. Where is the evidence? It is far more likely that the infection was spread by the movement of domestic poultry, even long distance in trucks so conveniently transported in a coup, and then spread locally by people taking birds to neighbouring villages and towns to trade or as a gift for relatives and so on, as virtually all households in rural areas and on the edge of towns in Turkey apparently keep a small number of poultry. Once this was so in Western Europe. I have come across an Irish Poultry Coup Dresser. The chickens used the lowest portion of the dresser that was fitted with a pop hole in a slatted door conveniently opening for cleaning. Cosy and safe they must have been, in the kitchen under the plates and cups- with a warm freshly laid egg in the morning taken out from the nest by a small arm reaching through the narrow gap. Relatively few households now keep chickens in Western Europe. The flocks, even the large commercial flocks of tens of thousands, are isolated in comparison to Turkey where the extensive network of domestic poultry acts like a leaky sieve allowing the transmission of a highly infectious virus for poultry to spread far and wide in a short space of time.
The numbers of birds culled in Turkey is as yet not so large that one could not contemplate replacing the culled birds with vaccinated ones. The announcement of an effective vaccine developed by Dutch virologists makes this a possibility.
For all the reasons above- Turkey’s openness, the important nutritional value of poultry to poorer people especially children, the likelihood of persistence of H5N1 infection in domestic poultry in Turkey acting as a reservoir for human infection and wild bird infection, the leaky network of subsistence poultry keeping allowing extensive transmission even into neighbouring countries- a different policy for Turkey other than simply culling should be adopted. Is WHO able to do something different?
Dr Ruth Watkins