Published Dec 6, 2010
Belle Epoque
156 Posts
There's a recent TB thread which is prompting me to ask the following question (but figured I'd create a separate thread to keep things neater.)
What are your thoughts regarding the BCG vaccine in childhood causing false-positive results with the 2 step Mantoux test in adulthood?
I've heard various explanations and not sure which camp to believe.
heathert_kc
270 Posts
I didn't think there is anything controversial about it. If you received the BCG vaccine as a child, as many people, particularly those born in countries where TB is or was more prevalent did, you will likely test positive for exposure to the TB bacterium (done by TB skin or serum tests) , because you were essentially exposed (through the bacteria used to create the vaccine). TB skin test or blood tests for that matter only show exposure and DO NOT necessarily indicate that you have the latent infection or disease. That is why a follow up chest x-ray or other tests are done to ensure that you are not actually infected, but merely had some level of exposure.
My husband was born abroad and receive the BCG vaccine and has always tested positive. He has never had TB or any symptoms...It's no big deal he just gets his chest x-ray.
Is there something else you're talking about that I am not understanding? The connection (between BCG and positive TBs) is very well documented. check out the CDC's website for more info: http://www.cdc.gov/tb/topic/testing/default.htm
TiffyRN, BSN, PhD
2,315 Posts
I started a thread about this quite a while ago outlining the multiple issues I've had after getting BCG as a child and the many positive PPD tests I've had since.
The update is that since then there is a test called the Quantiferon TB Gold that distinguishes whether a person has immune response to TB vs. BCG. The PPD skin test reacts either way. My employer wanted me to be treated for TB which of course I resisted. I suggested the Quantiferon TB Gold test but apparently that was too expensive (and at the time only available from the CDC). We decided they would just continue with annual screening which consisted of a questionnaire and leave it at that.
The thread I started: Positive PPD with history of BCG - Nursing for Nurses
Link to Wikipedia entry on Quantiferon TB Gold: QuantiFERON - Wikipedia, the free encyclopedia
Elvish, BSN, DNP, RN, NP
4 Articles; 5,259 Posts
I have read many PPDs of people (including children) who received BCG at some point. Probably only about half those PPDs popped up positive. (I used to work at a clinic that did immigration physicals, and a PPD is a standard part.)
Is there a connection? If the CDC says so, then I'm inclined to believe there's a connection, though not necessarily a strong one. It's not a guarantee that just because someone receives the BCG they will always have a +PPD. And most of the rest of what I was going to say, the CDC link already says.
regularRN
400 Posts
Well, I always test positive on the PPD, as do all my friends and family who received the BCG.
PetiteOpRN
326 Posts
I started a thread about this quite a while ago outlining the multiple issues I've had after getting BCG as a child and the many positive PPD tests I've had since.The update is that since then there is a test called the Quantiferon TB Gold that distinguishes whether a person has immune response to TB vs. BCG. The PPD skin test reacts either way. My employer wanted me to be treated for TB which of course I resisted. I suggested the Quantiferon TB Gold test but apparently that was too expensive (and at the time only available from the CDC). We decided they would just continue with annual screening which consisted of a questionnaire and leave it at that.The thread I started: Positive PPD with history of BCG - Nursing for NursesLink to Wikipedia entry on Quantiferon TB Gold: QuantiFERON - Wikipedia, the free encyclopedia
My employer recently started offering Quantiferon gold testing. I have never had the BCG vaccine, but when I was a newborn received the mantoux test several times and developed an allergy to phenol, a preservative in the mantoux test. I have a severe reaction to the mantoux test, which includes a "hive" at the injection site that is read as positive. I resisted prophylactic treatment for years, and I'm so glad this test is finally available.
britgirl37
50 Posts
FYI, if you have had the BCG (as I have) and have a positive PPD test, you have the right to refuse further PPD tests. This is (as I understand it) because the more PPD testS you have, the worse your reaction can get. You just fill in the questionnaire and have the chest xray (most hospitals require one every 5 yrs, some every yr). Some managers don't quite understand this, but the Employee Health people are fine with it.
Thanks to everyone for their helpful responses.
I'm not familiar with the Quantiferon test and suspect it isn't available in my area otherwise I likely would have heard of it. It sounds like it would solve many of the problems those of us who test postive on the PPD have to contend with.
My experience is that irregardless of what the CDC says many practitioners have strong feelings about whether it's BCG related or not, everything from "yes, it is most likely the cause of positive skin tests" to "no, absolutely not, the BCG vaccine was given too long ago to have an effect now so you must have been exposed." Where? I am not at high risk of exposure. You would be surprised at the conflicting beliefs. I also had public health nurses who supported the probable correlations and others who opposed it vehemently.
I am one of those people who have no official record of having received the BCG except for a distant memory and unfortunately the parents are no help, so it is presumed I did, but not confirmed. This admittance bothers some professionals. I do always test postive with the skin induration which, at times, creates a havoc with whomever is doing the testing/reading in not accepting that it is likely BCG related and for the most part pushing for the prophylactic treatment. No thanks! I am not one to recklessly take Acet for a headache unless really bad let alone to take prophylactic anything! Er, except maybe rubbers, but that's beside the point.
Many employers and their OH departments don't understand it as well as they should either, which is unfortunate. I still get asked to receive the regular two-step Mantoux DESPITE the fact that my current GP has said there is no point in continuing this waste of time and money, and just go ahead with the CXR, but I still get "harrassed" on occasion depending on who it is. Seriously, this has been a thorn in my side especially since embarking on my professional life in the health care field.
If the health department and your employer are not willing to provide the Quantiferon test, see if your PCP could order it. The cost was prohibitive 6 years ago when I first found out about it, but as its become more common, the price has come down, and some insurances are covering it.
sunnycalifRN
902 Posts
Where I work, the Quantiferon Gold test is the only test used for TB screening. It does require a lab draw and only specially trained lab personnel are allowed to do the draw ( we're not allowed to do it in ICU ). Here's some info:
http://www.ctca.org/guidelines/CTCA_QFT_Position_Statement.pdf
galsem
1 Post
There's a recent TB thread which is prompting me to ask the following question (but figured I'd create a separate thread to keep things neater.)What are your thoughts regarding the BCG vaccine in childhood causing false-positive results with the 2 step Mantoux test in adulthood?I've heard various explanations and not sure which camp to believe.
I was born in East Africa where I was vaccinated with the BCG vaccine at the age of 11 years. I had a positive mantoux test (2 step) at the age of 50 years. My Chest X ray was clear but the Docs were convinced I had latent TB. They persuaded me to take isoniazid but my monthly blood tests were not monitored and after 5 months I went to my family doctor feeling quite unwell. My liver enzymes were very high and I had hepatitis. Needless to say I was very angry and still sceptical about the diagnosis of Latent TB. I finally managed to get the quantiferon blood test which conclusively proved that I did not have latent TB and my skin reaction was therefore due to the BCG vaccination 40 years before. You would think that this happened in the third world country but the care I received was in Canada and by what I thought were knowledgable Infectious Disease Doctors. The doctor in charge of my care was even a professor at the university here. It's quite surprising.
starry_eyesgk
6 Posts
I had the BCG twice in my life, one just after birth at about 6 months, and one at 12 years. I was born in Singapore and there, everyone was made to have the BCG. Since then, before I was allowed to start nursing school here, I was forced to have the Mantoux test in 2003, and the reaction I had was overwhelmingly severe on my arm, that my skin began to quickly necroze from my AC to my wrist. My then husband, who is a dermatologist, was furious with my SON, because he had warned them that I had already had the BCG twice and would have false positives, but was shocked that the reaction was that severe with me. He had to put me on high dose steroids to stop the reaction, and took care of my arm the way he knew how to, as a dermatologist would. Eventually it healed. He had threatened lawsuit with the SON. Since then, and I have been a nurse and now an NP as well, I have had CXRs instead of these Mantoux tests, but occasionally get harassed by hospitals who insist that I have the Mantoux. I put my foot down and tell them that they will have to pay for CXRs if they want proof that I'm clear, as I have never had symptoms, and if they start pushing back, I yell "lawsuit" and they back down, or I tell them they can shove their job somewhere else. One hospital accepted my CXR so far. I have now another hospital beginning to argue about it. I will tell them that I'll be happy to have the Quantiferon Gold if they'd like for me to get one, but they'll have to pay for it.
We shall see what happens again, but it gets very tiresome with each time I get push back from a clueless hospital administration when I'm sent there to work for a few weeks or so, to cover someone on leave.