well, the test wasn't FALSE, it was just taken at the wrong TIME. what none of us wants to deal with is that a NEGATIVE test is no more probative than a POSITIVE test is, because it can take as long as 120 days for the antigen to register on the test as it can to work its way out of the cat's system....
i know this; many of us know this--but we still take that negative as truth, unless we have a good reason not to. but it doesn't make the TEST wrong.... do you see the difference? about the bone marrow--that's why i'm asking--i've never found anything OFFICIAL that says that's what the IFA tests for. i know that's what it's generally believed to be, but i can't find where that is anyway actually defined. and whomever just wrote said, "my vet doesn't think it's in the bone marrow." and again, if you do an IFA at the same time as the ELISA, you will often get the same result--but if you read the literature, even something that someone loudly used to prove me wrong earlier this year, it's always conditional: "MOST cats who test positive...." in fact, one of the people who was most vicious to me about it just had one of her cats test negative on the IFA, after the cat has lived exclusively with positives for quite awhile. oops. personally, i wouldn't do an IFA for 120 days following a positive ELISA. i'd never believe either a positive OR a negative result, because i know that tests are looking for EXPOSURE. if i got a positive on an IFA 120 days after an ELISA, i'd accept it. if i got an positive on an IFA earlier, i wouldn't, because i've known too many cats to show positive IFAs early on, and then negative ones later. as stated originally, an OLD version of the merck manual mentioned a study with a cat not reverting to negative on an IFA for a much longer time--had i know they were going to pull that reference, i would have copied it down! if anyone has a really old copy--prior to 2002, please check... i read that very early on when i was living at the sanctuary, so i NEVER heard the "bone marrow," thing, nor the "IFA can'ts turn negative" til years later--long after i'd seen positives turn negative. that's why i'm asking--so that once and for all, we can track it down, and find out what is REAL. i know that a few months ago, i asked this on another list, and tried to find it myself--and never got any responses, NOR was able to find one citation that said, "the IFA tests for presence of the virus in the bone marrow." i know that the wording is, "in most cases," "most cats" about the accuracy of a positive IFA because that's in many references--but MOST is NOT ALL, and none of those articles ever factor in the exposure. which, as chris says, is the entire issue with FeLV. i don't know why we test for antigens in FeLV and not antibodies as we do with most other things; i think that's part of the confusion...... i've also found out that anything published before about 2004 can't necessarily be taken as FACT, because they have finally started doing research on FeLV--so some of the things we thought we KNEW back then have been proven untrue..... which makes it that much harder to keep up on stuff. and all the more important that we, their only advocates, makes sure that WE are informed. sometimes it seems that we're the only ones who care. MC On Wed, Oct 29, 2008 at 2:22 PM, Chris <[EMAIL PROTECTED]> wrote: > Just for my own info... I thought IFA would show if the virus has spread > to > bone marrow and that a pos IFA was pretty accurate determination.. Am I > wrong on that? > > And you can have false neg Elissa --My Tucson was one of those--she got > tested as a very young kitten and obviously, exposure had been recent--5 > years later she (an indoor spoiled 18 pounder), tested pos on both Elissa > and IFA. Two vets confirmed that neg test was likely because of timing. > > Christiane Biagi > Cell: 914-720-6888 > [EMAIL PROTECTED] > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of MaryChristine > Sent: Wednesday, October 29, 2008 2:13 PM > To: [email protected] > Subject: Re: [Felvtalk] tests > > please provide information about the PCR test you're talking about. the > last > i'd heard, there were none available that wree consistently accurate and > reliable--they've been working on this for a long time and haven't been > able > to establish a test that's acceptibly accurate across many labs. > > i know that they HAVE developed one for FIV to determine if the virus is > vaccine-induced or not, but as of a month or so ago, it still wasn't > commercially available, tho it's expected to be soon. > > as far as everything i've read, at this time, the IFA is still considered > the confirmatory test for FeLV. i'd love to see anything newer. > > what has to remembered with FeLV is that, unlike FIV, the ELISA test is for > ANTIGENS, not antibodies--so a cat can test negative merely because the > exposure was too recent tos how up--so the negative isn't "false," it just > was too early. likewise, false positives may be false positives from all > the > things inherent in the test, but they can also be true at that time: the > cat > has been EXPOSED to the virus. antigens are NOT an immune response, > however, > just an indiciation that the kitty has been closely exposed to the virus. > > this is where the biggest misunderstandings arise: most adult cats will > throw the virus off anywhere between 30-120 days--their immune systems will > just knock it out. then a test will be negative because there are no longer > antigens wandering around irritating them. but if you test too soon, you'll > just get another positive result because the cat's body hasn't had the > chance to work the virus out. > > doing an ELISA and an IFA right away will probably give you the same result > on both of them, because it's the EXPOSURE that's showing up. the only real > way to know is to consider a positive result for what it is: an indication > that kitty was in close contact with someone who had the virus. (we don't > know for sure, as far as i have seen, that a cat on the edge of throwing > off > the virus itself can't still pass it on, perhaps at a subclinical > level?)--if you know when the last date the kitty could have been in > contact > with another cat, test if 90-120 later than that..... with the IFA (or if > there really is a DNA/PCR test newly available, that one) > > and then make the decisions. > > MC > > > On Wed, Oct 29, 2008 at 11:36 AM, Saehwa Kang <[EMAIL PROTECTED]> wrote: > > > The ELISA test takes a blood sample from the lower leg, and is > > inexpensive. It's not that accurate, as there are false positives and > > sometimes false negatives. We had 2 three month old kittens who became > > negative within 1 month, and one that became negative 3 months later. > > > > You can retest after about 2-3 months with the Elisa again. Better yet > > is the IFA test. It checks whether the felv has reached the bone > > marrow- the vet sends a blood sample to a lab and is a tad more > > expensive but much more accurate. > > > > However,the best alternative after a positice elisa test is the new > > PCR test. It's so new you won't see it in many google searches. It can > > detect even minute quanitites of the virus and is the most accurate > > test out there- also sent to the lab. Best after two consecutive > > positive ELISA tests. > > > > Your kitties can fight off the virus and change to negative though > > it's not guaranteed. They probably got it from their mother. Many > > kittens can and do fight it off which is why early testinf is often > > inaccurate. In order to do so, you'll need to provide a low stress > > environment, indoor only home to reduce exposure to germs, premium > > food mostly canned (wellness, innova evo, natures variety > > instinct,etc), clean the litterbox and dishes daily and have more than > > one box, vaccuum and keep them flea and worm free, as well as spend > > time playing with the kittens and giving them affection, toys, warm > > places to sleep. > > > > There are no guarantees but it is possible to go from positive to > > negative. Just takes dedication and having hope... > > > > And others will tell you a felv positive diagnosis is not a death > > sentence! > > There are plenty of people here who have healthy cats with felv that > > have had long lives. > > > > I don't know about financial assistance, but you should try and talk > > to your vet about payment options. The cheapest ELISA test I found ran > > about $25-30 here in LA. > > > > Also, you can do you best to change their positive status to negative > > in the next few months. Even if they don't, you can adopt them out > > when they are a bit older after you've tried or just try to adopt them > > out now and tell people they are positive for now but could change.. > > > > > > On Oct 28, 2008, at 7:51 PM, SALLY NORDSTROM <[EMAIL PROTECTED]> > > wrote: > > > > > I'm getting real confused about the available tests and their > > > accuracy. Can anyone shed some light on this for me? > > > > > > I had to file a bankruptcy and can't afford testing. Is there > > > someplace that can give me help? > > > > > > How hard is it going to be to place my rescued kittens in homes? > > > What resources should I be using? > > > > > > > > > > > > _______________________________________________ > > > Felvtalk mailing list > > > [email protected] > > > http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org > > > > _______________________________________________ > > Felvtalk mailing list > > [email protected] > > http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org > > > > > > -- > Spay & Neuter Your Neighbors! > Maybe That'll Make The Difference.... > > MaryChristine > Special-Needs Coordinator, Purebred Cat Breed Rescue (www.purebredcats.org > ) > Member, SCAT (Special-Cat Action Team) > _______________________________________________ > Felvtalk mailing list > [email protected] > http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org > > > _______________________________________________ > Felvtalk mailing list > [email protected] > http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org > -- Spay & Neuter Your Neighbors! Maybe That'll Make The Difference.... MaryChristine Special-Needs Coordinator, Purebred Cat Breed Rescue (www.purebredcats.org) Member, SCAT (Special-Cat Action Team) _______________________________________________ Felvtalk mailing list [email protected] http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org
