From:
daneedv@aol.com
Date: 2002-05-19 13:51:00 UTC
Subject: Re: ADV test kit
In Ferret-Health-list@y..., "sukieferret" wrote:
>
> I'll have to see if i still have it but Dr. Stephon once
sent me the
> results of their in-house testing for accuracy of their
approach
> hat happened up-front. There were not a lot of tests used
> (especially those which resulted in positive readings) so
that
> itself can cause problems not knowing actual accuracy
rates.
>
>
Both Dr. Murray and I were part of the initial testing.
People might want to refer to message #5253, where Dr. Murray
discusses the results of from the samples he provided for the
Beta test for the ELISA. I believe that overall, there were
only about 200 ferrets involved in the Beta test, and there
was about a 90% agreement between the ELISA and the CEP tests.
In my own case, I had 32 ferrets that were tested both by
United CEP and Avecon ELISA. I drew blood and collected
saliva at the same time, and sent blood to United and saliva
to Avecon. Of my 32 ferrets, 9 tested positive by CEP and 23
tested negative. By ELISA, only 8 tested positive, and 24
negative, so there was only one discrepancy. Unfortunately,
it was Moonshine, and we have since shown that he definitely
has ADV, although at the time Dr. Stephon was insistent that
since he tested positive by ELISA, he could not have ADV.
Dr. Stephon later admitted, when he spoke last June at the
Planned Ferrethood Show, that there may be times when his
tests will give a false negative response. I still have the
video of this talk, BTW. Because his test looks for only one
protein from the antibody that is only present when the virus
is replicating, if the virus is present but dormant, his tests
may give a false negative. This will not happen with the CEP,
because it tests for several different proteins, and gives a
positive reading if any of them are present.
My personal feelings on the tests are this - I think both the
CEP and the ELISA are fairly accurate. I do not have much
experience with the POCT, but I know that Dr. Stephon ran a
number of side by side tests with the POCT and the ELISA, and
found the 2 to produce nearly identical results. I think most
of the problems that come from using the POCT with saliva may
be due to errors made by the person giving the test. I
specify with saliva, because from what I have heard, there may
be problems when using blood. Although at one point I was
hearing that Dr. Stephon was telling some people to only use
blood (and I did see copies of some emails where he said
this), everyone I know that tried using blood with the POCT
ended up getting a very high false positive rate with the
tests.
I find it very unfortunate that Dr. Stephon has not made some
kind of public statement about his tests. I had looked
forward to seeing him at the recent Pittsburgh Ferret Show,
and was disappointed he chose to cancel on them at the last
minute, although he may have worried how people would receive
him. Personally, I thought it would be an excellent chance
for him to publicly set the record straight about his tests.
The sad thing is, some of the people that initially raised
concerns about the accuracy of the POCT tests have now posted
on lists that in hindsight, they are fairly accurate.
No test is ever 100% accurate - that is why it is always good
to retest and to verify results with other types of tests.
If I were running a shelter, I would not take any ferret in
without testing it for ADV. If I had an area to quarantine it
and keep it totally separate from other ferrets, I might be
willing to wait for results from the CEP test. But, many
shelters do not have that kind of space. For them, I think
something like the POCT test can be very useful.
One other comment I would like to make - when the recent
testing controversy came up, I wrote to a number of vets from
across the country, and asked them their thoughts on it. Most
of them did not have experience with either of the Avecon
tests, and so would not comment on them directly. They did,
however, raise concerns about saliva testing in general,
stating the historically, when saliva tests have been
developed for other diseases in other species, they have
eventually proved to be less accurate then blood. My own vet
was very skeptical about using saliva to test for ADV when I
first told him about the Avecon ELISA. ELISA tests are
extremely accurate, providing they are testing for the right
protein, and have a good sample. His concern was not with the
test, but with the sample.
Danee
ADV - If your ferret hasn't been tested, you don't know!
For more information visit
http://www.geocities.com/russiansmom