TB and rapid testing

Originally from: frances fish
                        
Does anyone out there know whether something of the RT-PCR type could be used to test for TB ? Is it possible ? Current skin testing is upwards of 30% inaccurate and I believe that the interferon version also has its problems( It was abandoned by the Irish but, of course is being half-heartedly trialled by Defra).The impression is, perhaps wrongly, that Defra doesn't want any test that is not open to their own interpretation, if it suits them, its positive. This way they have a measure of control. If a test that was openly positive or negative was to be used they would lose that. Frances

Originally from: Bill
                        
I see RT-PCR testing has been used to identify cancer antibodies and therefore, theoretically, it could be used to identify tuberculin antibodies, Frances, so my apologies.

However RT-PCR testing is generally only used as confirmation, ie it's a lot easier if you know in advance what you are looking for! Even so, you are only 70% likely to get a positive so this method wouldn't be any more accurate than the 70% accuracy of existing TB testing.

As yet there are no tests that give clear cut answers for anything, it's mostly down to spotty youths peering into a microscopes and deciding between different shades of fluorescent pink!

All the best,
Bill.
                        

Originally from: Bill
                        
The test is for viruses, Frances, the RT bit refers to reverse transcriptase.

All the best for the New Year to each and all.

Bill.
                        

Originally from: Bill
                        
Many thanks, Frances.

I'm not familiar with V-Scan so will have to look it up and get back to you.

The main problem with antibody testing is the time lag between infection and detectable levels of antibody in the bloodstream. With FMD the time lag is anything from 3 to 21 days. Virus can be similarly elusive, virus causing disease in organs or lymphatics isn't necessarily present in the bloodstream.

The only way to be reasonably certain is to test for both virus and antibody, but of course the cost is prohibitive and in any case there aren't sufficient trained technicians.

There is of course another alternative, do away with tests altogether and go back to the days of clinical diagnosis by the Local Authority veterinary officer. Of course the bureaucrats would never go for that, and we don't have enough vets sufficiently competant to fill the posts of veterinary officers!

There is no easy answer.

All the best,
Bill.
                        

Originally from: frances fish
                        
Hi Bill, Happy New Year, and thanks for the info. Do you know anything of a test called V-Scan, marketed by the Chinese I believe and said to be much more accurate and only to detect active disease ? There has to be something better out there than to kill rather than detect ?Am I howling at the moon, do you think ? If there really was a better option, would the powers that be, be interested.? As I said, it suits their purpose to have a test where they control the result and the outcome .As a local farmer said about the fallen stock scheme, they will be collecting more than dead animals from you.We have learned to be cynical, I'm afraid. Frances
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