C DIFF NEGATIVE TEST, doesnt make sense

[Ashley86]

Hi friends, so I have been on either flagyl or vanco since January, and am currently in my second 8 week taper for Vanco. In the middle night Monday evening, the D began out of nowhere, the stomach pains were back and you all know the rest, the pain and D continued... I called my DR immediately Monday because I had last taken my Vanco Saturday and was off SUN and Mon and was to take it Tuesday AM ( which I did) the pain was so bad I took 2 125 mg pills, then 2 more on Wed as the pain was getting worse, so Thursday morning he said do not take any vanco and go to lab and get a stool sample. the doctor just called me back that my test came out negative. I am so confused, I KNOW when I am having a C DIFF episode, I know it is not a bug, he is wondering if the VANCO masked the sample and thats why it came out negative, I was allowed to take a vanco last night (which i did) and honestly on a scale of 1 to 10 I feel about a 7. Has anyone else has an issue with out of no where you were on the drug therapy you had an attack like this in the middle of taking your meds like I did? And you took a test and it came back negative??? my husband really pissed me off he says "oh you probably just had a bug" No i did not just have a bug, I know how this devil works, a bug doesnt make you live in the bathroom 9 to 15 times a day and the awful stomach pain with no appetite. I literally didnt feel sick just beat up from the pain. Please let me know if anyone else had issues? My doctor now wants me to hopefully go until Sunday without taking any vanco. This is just all so crazy. I dont even know if this makes sense.

Best,

Ashley

[susant]

Vancomycin can and does cause false negatives. I'm surprised your doctor doesn't know that. Vanc can be very hard on the gut especially the longer you take it.

[roy]

The reason testing is not done while on meds is that vanco kills the active c.diff and not the spores.
Dormant spores can not be detected
Testing 10 days after finishing meds is more accurate as it allows time for the spores to vegetate (if they are still there) and produce toxins and then it can be detected.
For your current problem to be c.diff related there has to be toxins present in your gut and stool so I would think a test would detect them even if you are on meds.
Was it a PCR test? If so it should be correct.
EIA tests are not accurate.

[Ashley86]

thanks Roy, yeah the issue for me I have had 8 relapses since Janaury, I haven't went more than 5 days without the devil returning. It is really running a course on me, our next step is the fecal transplant. And yes my doctor is aware that the Vanco probably masked the CDIFF, he is extremely smart hes just shocked that I am 30 years old and haven't been able to kick this, I will be his youngest FMT patient.

[amyc]

Shigella, salmonella, and the nasty E. coli can cause your exact same symptoms as well. The PCR test checks for the DNA of the toxin, so if you were having an active C diff infection it should have picked it up, regardless of medication use. The reason they ask people to wait a week to 10 days after stopping meds is so they don't get false positive results and over treat. The test is so sensitive that it will be positive for a couple or few days while your body is re-establishing its own flora. Vancomycin absolutely does not interfere with the test itself.

That said, the test is only 94% accurate as compared to the full culturing followed by cytotoxicity assays that take a week and a lot of work to do, and are thus only used for research or to gauge accuracy of tests :). So it's entirely possible you are in that unlucky 6%. But it sounds like you have a great doctor who is taking your case very seriously and isn't blowing you off because your illness is difficult. My doctor was stunned when I got C diff 6 years ago because I was a healthy 42 year old. You don't have to be 80 and in horrible health to get C diff.

Now If you were given the old EIA test, well it's only like 70% accurate, and that's the data from the manufacturer where they handle the specimens perfectly and run the test under conditions to get the best result to publish. And I have had a lab run the EIA after my doctor ordered the PCR test.

Sorry if this is too inside baseball. I have a master's in this stuff, so I find it interesting. And I have run PCR tests (not for C diff, but as part of my research) and hope anything I can share might help others understand the stuff.

[Sweet]

I was not even on anything when my stool tested a negative when it was a positive. redid the test weeks later and i was same as the positive one. Docotr said it can throw a false negative. I am done with my vanco and again i have been nauseous and in bathroom a lot and only been off vanco for 2 days. Doctor told me that it will take some time to get back to normal but i feel like i am going backwards into my sickness again. I am going to a different doctor in july but dont think i can wait that long. :( Good luck Ashley.

[Lisa33]

Has the doctor mentioned trying Dificid as one last ditch effort before an FMT? There are several posters on this site who were cured by Dificid or Dificid tapers after vanco tapers failed. Dificid has a high cure rate and does not kill good gut bacteria. Are you taking probiotics, as they can be beneficial in replenishing good gut bacteria.

As the others said, if you test while on vanco, it's highly probably to get a false negative.

Lisa

[cdiffrun]

False negatives is very probably if your doc did the rapid antigen test. Per UpToDate regarding the EIA: "There is a relatively high false-negative rate since 100 to 1000 pg of toxin must be present for the test to be positive" http://www.uptodate.com/contents/clostr ... -diagnosis

Like Lisa33 said, before you resort to FMT you might want to try probiotics or dificid. I never had to try dificid thank God as I had luck with probiotics.

[Ril]

Probiotics alone do not treat c diff. In fact, there is no conclusive proof in the research that probiotics have an impact on c diff HOWEVER there are indications that they work and most GI drs do believe that they help. I think most of us who have had c diff have used them and probably still do and I personally believe that at some point the research will be able to prove their worth. I would not however advise anyone to try to use them alone to treat their c diff.
Rita

[cdiffrun]

Very true, check out this recent medscape article RE: Probiotics + Antibiotics may keep C diff at bay!
http://www.medscape.com/viewarticle/863777