More H5N1 Outbreaks in Czech Republic?
Recombinomics Commentary
June 28, 2007
Experts say they believe that the virus must have come from wild birds contaminating stacks of straw which was later used at the turkey farm. It could then have been transferred on the shoes of a worker or on a car tire between the two poultry farms which belong to the same farming cooperative.
This theory is supported by the most recent developments - one dead swan, now being tested, and close to 250 dead seagulls found near the Rozkos man-made lake near Nachod.
The above comments again mention the uncovered straw that was used for bedding in the turkey farm. This was a closed farm, and the straw is the likely source of the H5N1 introduction. The transmission to the second farm was likely due to poor biosecurity.
The dead swan is likely the swan described previously at the Czech/Slovakia/Austria borders in southern Czech Republic. Local tests were H5N1 positive, and samples have been sent to Prague for confirmation. There were also dead birds with bird flu symptoms near Litomysl.
However, the 250 dead seagulls near the northern border with Poland would signal significant H5N1 infections if these birds also test positive for H5N1.
Media reports indicate the Czech turkeys have 99.5% identity with H5N1 from Kuwait, while the identity between the Nurenberg wild birds and the Czech turkeys is 99.2%. This level of identity is common for Qinghai clade 2.2 sub-clades.
However, this level of identity is markedly lower than the 99.96% between isolates from Hungary and the UK. In those outbreaks, it is likely that the H5N1 in Hungary was transported to the UK.
The frequencies in Kuwait, Germany, and the Czech Republic support independent introductions by wild birds.
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