Wednesday, September 01, 2010

The 'disappeared'.

The posts below and here highlighted the difference between the figures which Defra produce to illustrate tuberculosis overspill into other species, and the grim reality of just how many animals are now dying.

We collect paper at blogger headquarters and in a trawl through various print-offs from Defra's 'other species' website over the last year, we note that the explanatory notes for these tables are getting longer - in direct proportion to the number of animals reported, which is shrinking.

A year ago the explanatory notes were as follows:
* Infected = positive for m.bovis on culture

** All data for 2009 is provisional and subject to change as more data becomes available. Current data has been collected during the period Jan-July 2009

Note: We can only provide data on the number of m.bovis isolations from notified clinical and postmortem cases of TB arising in some non bovine species.

Data to be updated on a quarterly basis - last updated 11 August 2009.
This is when the figure of 17 dead alpacas was challenged by vets running the TB in Alpacas roadshows, who had collected members' data which totalled, anecdotally of course, around 200 dead.

So fast forward to earlier this year, when these figures had not moved from Defra's November posting of 68 dead alpacas. The note adds that:

Data for 2009 is provisional and subject to change.
NB Current data has been collected during the period Jan-Dec 2009 but some culture results are still pending.

Note 1: We can only provide data on the number of M. bovis isolations from notified suspect clinical and post-mortem cases of TB arising in some non bovine species.

Note 2: Cultures and post mortem examination may not be carried out at the VLA on every animal removed from a herd once TB has been confirmed.
Therefore not all animals removed for TB disease control purposes will be reported above.
And one assumes that they are still 'pending' as the figure of 68 has not been upgraded. Or perhaps the samples were all negative. But it is clearer that when a group of animals are still having fatalities, only the first couple of samples are counted in these tables.
So we started asking a few pertinent questions as both pigs and camelids from personal communications, were just not showing the full extent of TB 'spillover' deaths.

And the new tables have an even fuller explanation of just what Defra are not counting. And it isn't dead 'other species' TB victims. The charts in August came with the following health warning:
Veterinary Laboratories Agency TB Culture database
* Infected = positive for M.bovis on culture

** Data provided for 2010 is for the period 1 January - 30 June 2010.
All data provided for 2010 is provisional and subject to change as more data becomes available.

Note 1: We can only provide data on the number of M. bovis isolations from notified suspect clinical and post-mortem cases of TB arising in some non bovine species.

Note 2: Cultures and post mortem examination may not be carried out at the VLA on every animal removed from a herd once TB has been confirmed.
Therefore not all animals removed for TB disease control purposes will be reported above. i.e., where multiple skin or blood test reactors are identified in an infected herd undergoing TB testing.

Note 3: The figures represent submissions from individual animals, not premises i.e. Several submissions may be from the same premises.

Data to be updated on a quarterly basis - last updated August 2010
So, when one looks for figures of 'other species' TB casualties on Defra's website, it is probably more informative to read the notes and see what isn't being counted, especially those detailed in Note 2.
Note 2: Cultures and post mortem examination may not be carried out at the VLA on every animal removed from a herd once TB has been confirmed. Therefore not all animals removed for TB disease control purposes will be reported above. i.e., where multiple skin or blood test reactors are identified in an infected herd undergoing TB testing.
Skin and blood test failures? Not counted. Deaths where no cultures have been collected, but gross pathology has indicated TB? Not counted.

These animals are dead. They have contracted tuberculosis, which is usually identified as the spoliogotype 'indigenous to the area'.

They have 'disappeared' from Defra's radar. And that is by no means good enough.

The cynical amongst us would perhaps comment that by shrinking the TB overspill problem to just a few culture samples, even with increasingly convoluted explanations of how this is done, the problem will, er shrink away. Don't count the bodies, so the bodies do not exist. They are the 'disappeared'. Simples.

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