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Can BCG Vaccination Cause A False Positive Reaction To A TB Skin Test?

Posted on Mon, 8 Aug 2016

Question: TB patient from UK - I dont know why the previous chat was closed. Ok. My wife is also XXXXXXX She is here in the UK for last 11 years and she has spent 22 years in XXXX XXXXXXX

Answered by Dr. Drkaushal85 (11 minutes later)

Brief Answer:
Wow. I am also from XXXXXXX XXXXXXX

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
I can understand your concern.
Isn't it amazing?
I am also from XXXXXXX XXXXXXX
It's nice to hear from Gujarati people on this forum.
Since she was born in XXXXXXX she must have taken BCG vaccine at birth.
And this vaccine in childhood can cause false positive skin TB test.
So practically speaking, skin TB test has no role for Indians.
You should not diagnose latent TB only on the basis of skin TB test.
Has she taken BCG vaccine at birth?
Please reply me answer of above asked question, so that I can guide you better. I will be happy to help you further. Wishing good health to both of you. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Drkaushal85 (10 minutes later)

Hi, I know you are from XXXXXXX Nice to meet Gujarati people.

Yes she had taken BCG in childhood. She has that skin mark on upper arm.

What other test can be done to make sure its Latent TB or not?

Thanks.

Answered by Dr. Drkaushal85 (6 minutes later)

Brief Answer:
Newer test, Interferon gamma release assay is done now a days.

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
I can understand your concern.
Instead of skin TB test, WHO recommended TB gold test. It is measurement of Interferon gamma release assay. Commercially it is known as TB gold test or TB Quantiferon test.
Has she undergone these test during work up of infertility?

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Drkaushal85 (28 minutes later)

Hi, I heard about this test but not sure Dr here did it together with other blood tests at the time of chest x-ray.

I will ask him on Wednesday when we meet and if not then we will request that to be done. Or we can do that privately somewhere.

will this Gold test give accurate result about latent TB?

Thanks.

Answered by Dr. Drkaushal85 (21 minutes later)

Brief Answer:
Well, honestly speaking accuracy of this test in Indians is also doubtful.

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
I can understand your concern.
Well, I don't want to confuse you more.
But accuracy of this test in Indians is also doubtful.
Indians have taken BCG vaccine at birth. So we are having protective immunity against tb developed since birth.
So TB antibodies are there in Indians.
So it is very difficult to interpret TB gold test in Indians.
We should not rely only on positive test value. We have to look for clinical symptoms.
In asymptomatic XXXXXXX patient, positive skin TB test or TB gold test don't justify tb treatment.
Hope I am clear. Sorry if you find this confusing.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Drkaushal85 (19 minutes later)

Hi,

Thanks for your reply. I think if there is no any real indication of the active or Latent TB, we should stay away from the TB treatment if possible, right?

Thanks.

Answered by Dr. Drkaushal85 (28 minutes later)

Brief Answer:
Yes, now you are getting my point.

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
I can understand your concern.
Yes, now you are getting my point.
Indians should not be treated on the basis of skin TB test or TB Quantiferon test if patient is asymptomatic.
So no tb treatment or TB tests for your wife.
Are you taking any liver supportive drug?
Are you taking any multivitamin tablet?
You should continue these drugs along with anti TB drugs for better outcome.
Please reply me answers of above asked questions, so that I can guide you better. I will be happy to help you further. Wishing good health to both of you. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Drkaushal85 (1 hour later)

Hi, yes I am taking Pyridoxine to avoid side effects of Isoniazid. Other than that no liver supportive drugs or multivitamins. Dr here did not recommend that I take any supportive medicine. But I can take some over the counter multivitamin if you think will be good and will not cause any liver problem together with TB medications.
Thanks

Answered by Dr. Drkaushal85 (13 minutes later)

Brief Answer:
You should take simple multivitamin tablet.

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
I can understand your concern.
Yes, you should definitely take one routine multivitamin tablet daily after lunch.
No harm in it.
In my tb patients, I also prescribe protein powder.
So you should start over the counter multivitamin and protein powder along with other drugs.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.

Above answer was peer-reviewed by : Dr. Raju A.T

Follow up: Dr. Drkaushal85 (59 minutes later)

Thanks for your answers today. I will start multivitamin from tomorrow. I will contact you again after meeting with Dr here on Wednesday. Till then have a good time. Bye

Answered by Dr. Drkaushal85 (10 minutes later)

Brief Answer:
Wish you good health.

Detailed Answer:
Thanks for your follow up question on Healthcare Magic.
Thanks for your kind words.
I will wait for reply on Wednesday.
Wish you good health. Thanks.

Note: For further follow up on related General & Family Physician Click here.

Above answer was peer-reviewed by : Dr. Raju A.T