+PPD Test

[Guest UVAPAC]

I was just looking for advice and wondering how other clinics workup positive screening PPD tests.  (No known exposure to TB)

 

We get a lot of patients with a +PPD who have been vaccinated with BCG.

 

 

How are most clinics/primary care offices dealing with these results?  

 

Typically I will document if patient has subjective symptoms of TB (fevers, chills, cough, SOB, etc), perform a physical examination focused on cardiac/pulmonary, and then send the patient for a chest x-ray.

 

Most of the newer guidelines are suggesting that anyone with a history of BCG Vaccine get a QFT (Quantiferon Gold Test) prior to a chest x-ray.

 

 

Is anyone treating these patients for latent tuberculosis?  Referring to ID?  Referring to TB clinics?  Treating them in-house?

 

Thanks

[ventana]

yup

 

 

brief summary

 

BCG vaccination will be very unlikely the cause of a >10mm in a immune competent >18yr old patient - you can just count this result as a Positive irrespective of BCG status

 

BCG - usually given before 1 yr of age in countries where TB is endemic (not USA)

look at the WHO web site to learn which countries this is

 

Quantiferon Gold is not susceptible to false positive from BCG vaccination

so yes use if for those that are PPD + who may have been vaccinated.

 

I do send over to TB state clinic as they will pay for the meds (and they are spendy)  BUT you can treat on your own with a little bit of research...... read uptodate and get written consent for meds

 

MUST be stressed that you MUST take all meds - only would consider treating on own with an incredibly reliable patient with great adherence.....

 

 

We do the three months of weekly INH and rifapentine (RPT) given by direct observation in correctional setting

[GetMeOuttaThisMess]

Most private pulmonologists will not treat TB but will refer to Co./State organizations. No pt. with hx of BCG vaccination gets a TST, ever. CDC doesn't even want folks to get a TST but rather a QGT. No CXR for annual LTBI follow up but rather a sx. questionnaire which they've previously had on their website. The reason I know this is that my former SP was the health authority for our county and provided TB tx.. I would do the annual screens on detention officers with prior positive TST's or those with prior BCG vaccination.

[Guest UVAPAC]

Most private pulmonologists will not treat TB but will refer to Co./State organizations. No pt. with hx of BCG vaccination gets a TST, ever. CDC doesn't even want folks to get a TST but rather a QGT. No CXR for annual LTBI follow up but rather a sx. questionnaire which they've previously had on their website. The reason I know this is that my former SP was the health authority for our county and provided TB tx.. I would do the annual screens on detention officers with prior positive TST's or those with prior BCG vaccination.

It's interesting that you say this.  

 

UpToDate essentially states that hx of BCG vaccine is NOT a reason to not do a TST.  (Suggests that it should have been at least 10 years since vaccine was administered).  

[WRUPAC56]

Here is a link to the CDC recommendations. Some of them are not backed by solid evidence

 

 

https://academic.oup.com/cid/article/64/2/111/2811357/Official-American-Thoracic-Society-Infectious?searchresult=1

[GetMeOuttaThisMess]

CDC site says TST can be used but may result in false positive. As previously noted, IGRAs don't result in same. Since a positive TST in a BCG pt. may result in a false positive why not just do the gold standard test (no pun intended)? What CDC is saying is that a negative TST could be interpreted as a negative but in these known situations we always did a two-step TST if there was a question with prior BCG. Initial TST primes the immune system and second test would then be positive resulting in an IGRA anyway. BTW, a positive IGRA is not used to dx. active TB.

[ventana]

slow down folks......

 

 

I fo TB stuff every day

I have a direct line and talk frequently with the TB state specialist

 

 

I read all the CDC linked guidelines

 

 

A few points

 

CDC says "SUGGEST" for quantiferon over TST - it does not mandate it and actually goes onto say that you can use TST if needed

 

Before people respond please go back up and read my initial post.  It is valid good info from the trenches....  And supported by UpToDate and the local TB specialist and the state......

 

 

As for why not do the quantiferon gold test on every one..... well it is somewhat of a crappy test with a lot of operator error possible in the lab (go talk to a lab tech about it). It is useful in certain situations, but COSTS well NORTH of $300!  A TST might cost $10.......   so in a system where we need to be aware of costs it would be illogical o spend an extra $290 to get the basic same screening potential. yes there is times where the TST is positive and the Quantiferon Gold is negative, but with each screening TST over QG you save ~$290 - no point in spending the extra money

 

Two other points

 

1- TST requires reading at 48-72 hours - and if the patient doesn't come back - well you have to redo

2- quantiferon gold is a very challenging test - require special handling, special collection, 16 hours of incubation by the lab just prior to testing and special equipment and training for lab personal.  It is not an easy test.   Commonly batched or sent out so delays are common.

[Reality Check 2]

The VA just did Quantiferon on me for pre-employment. It is required. My PPDs are all negative for 35 years+ and I got Tine tests as a kid in Texas.

 

My mum had TB courtesy of the Army and being a TB nurse on a ward, right granuloma, treated. Had to have a billion CXRs through her life and Quantiferon didn't exist then. Mum also lived on different continents as a kid but wasn't given BCG.

 

I don't give a PPD to a BCG recipient. Infectious disease guy locally told me not to. Have watched a huge itchy welt form and folks get really peeved at you for doing it and it lasts days to week and is quite uncomfortable. We do Quantiferon and there are usually CXRs by the load available. 

 

We lost our health district TB clinic so we have to count on Infectious Disease. Very inefficient system.

 

And, since TB can form almost anywhere in the body - CXR is only the beginning. Have seen Potts and fallopian TB as well. 

 

We used to have yeast control to give intradermal to check for hypersensitivity reaction. Haven't done that in a while.

 

I tried finding a reasonable protocol to refer to - but they are too confusing - too many variables.

 

Anyone have a reasonable chart?

[GetMeOuttaThisMess]

slow down folks......

 

 

I fo TB stuff every day

I have a direct line and talk frequently with the TB state specialist

 

 

I read all the CDC linked guidelines

 

 

A few points

 

CDC says "SUGGEST" for quantiferon over TST - it does not mandate it and actually goes onto say that you can use TST if needed

 

Before people respond please go back up and read my initial post.  It is valid good info from the trenches....  And supported by UpToDate and the local TB specialist and the state......

 

 

As for why not do the quantiferon gold test on every one..... well it is somewhat of a crappy test with a lot of operator error possible in the lab (go talk to a lab tech about it). It is useful in certain situations, but COSTS well NORTH of $300!  A TST might cost $10.......   so in a system where we need to be aware of costs it would be illogical o spend an extra $290 to get the basic same screening potential. yes there is times where the TST is positive and the Quantiferon Gold is negative, but with each screening TST over QG you save ~$290 - no point in spending the extra money

 

Two other points

 

1- TST requires reading at 48-72 hours - and if the patient doesn't come back - well you have to redo

2- quantiferon gold is a very challenging test - require special handling, special collection, 16 hours of incubation by the lab just prior to testing and special equipment and training for lab personal.  It is not an easy test.   Commonly batched or sent out so delays are common.

 

 

I don't disagree that the IGRA has been quite expensive.  CDC never "mandates" anything that has been up in the air (recommendations only), however I do know for a fact through direct discussion with them several years back in addition to our regional state TB authority (Tyler, Tx.) that their goal was to get away from TST due to several factors, 1) this exact discussion regarding BCG, 2) folks STILL not knowing how to correctly interpret a TST (there is no such thing as a "negative" TST, it is read as "0 mm"), and 3) their feeling the the IGRA was a more sensitive test compared to TST screening.  Yes, there are interpretation/"indeterminate result" issues with it but all things being equal, I'd still trust it more than the TST.  I agree with RC2, CXRs are poor screening tools for active TB as she correctly pointed out, thus the CDC recommendation of an annual screening questionnaire as opposed to the CXR.  We used the questionnaire verbatim as recommended by CDC for annual screens.  Only if there were concerning responses did we proceed with a CXR.  If something has changed in the last 3 years with their recommendations then I apologize for the any comments that may have generated a backlash.  Our "high risk" folks (detention officers) were never required to take LTBI therapy though it was offered annually if never taken before.  Things may be different in other parts of the country but here, all TB folks that we ever interacted with went through governmental based clinics after being declined by either their PCP (understandable) or even private practice pulmonologists/ID specialists (and that includes a couple of local university medical schools), at least to the statewide exposure that we had (hey, it's a big state!).

[medic25]

 

I don't give a PPD to a BCG recipient. Infectious disease guy locally told me not to. Have watched a huge itchy welt form and folks get really peeved at you for doing it and it lasts days to week and is quite uncomfortable. We do Quantiferon and there are usually CXRs by the load available. 

 

I can vouch for this reaction.  I had the BCG in elementary school (standard in Ireland).  When I got into health care for a career I had a PPD placed, and by the end of the night half of my arm was covered in a big, itchy red welt which lasted for days.  After that I refused to let anyone else plant one.  Whenever I've started new jobs since then I always used to end up with a CXR and questionnaire, but for my last moonlighting job I had the Quantiferon drawn instead.  

[loliz]

It doesn't matter if you "can" treat privately, TB is a reportable disease and the county or state health department must ALWAYS be notified. Usually, they will take over the treatment as most areas have pretty good programs to monitor compliance and completion of treatment. 

[HMtoPA]

Quant Gold is specifically NOT to be used as a confirmatory test for TST screening.

 

In my experience, I see a LOT of POS TSTs in folks w/ a Hx of BCG vaccine >10 years ago. I almost expect all of my Filipino patients to have positive PPDs, and we treat them all for latent TB, although I strongly suspect most (if not all) are false positives due to a Hx of BCG vax. YMMV.

[Guest UVAPAC]

It doesn't matter if you "can" treat privately, TB is a reportable disease and the county or state health department must ALWAYS be notified. Usually, they will take over the treatment as most areas have pretty good programs to monitor compliance and completion of treatment. 

 

After some additional reading latent TB is not required to be reported to county/state health department.  Only confirmed active cases of TB must be reported.

 

http://www.wakegov.com/humanservices/publichealth/providers/Documents/Frequently%20Asked%20Questions%20about%20TB%20Skin%20Testing%20and%20Reporting.pdf

 

Interesting link from TB clinic in NC that apparently deals with these cases.  They suggest planting PPD's on people with hx of BCG vaccine.  In other words, it seems like everyone/everywhere has a somewhat different recommendation.

 

 

The funny thing is, 95% of patients who we have referred to their primary care physician for treatment of latent TB, generally are never treated.

[ventana]

I can vouch for this reaction.  I had the BCG in elementary school (standard in Ireland).  When I got into health care for a career I had a PPD placed, and by the end of the night half of my arm was covered in a big, itchy red welt which lasted for days.  After that I refused to let anyone else plant one.  Whenever I've started new jobs since then I always used to end up with a CXR and questionnaire, but for my last moonlighting job I had the Quantiferon drawn instead.  

 

 

But this would be classified as an AE to TST and therefor you should not have it - for no other reason then the skin response (outside of BCG status)  

I have this occur with some derm folks - eczema and psoriasis sometimes precludes TST

[loliz]

After some additional reading latent TB is not required to be reported to county/state health department.  Only confirmed active cases of TB must be reported.

 

 

Yes- I meant actual active TB for treatment. Latent TB doesn'tt need to be reported to health dept and often isn't treated. 

[pavlovacloud]

We work with a large Asian immigrant population at our clinics. For +QFT or +PPD, we order CXR. If XR is negative for active TB and hepatic panel WNL, we offer them INH x 6-9 months and monitor their ALT/hepatic panel. I have seen 2 active TB cases since working at this clinic (1 year). We rather treat suspected LTBI than risk it developing into active TB.

[HMtoPA]

We work with a large Asian immigrant population at our clinics. For +QFT or +PPD, we order CXR. If XR is negative for active TB and hepatic panel WNL, we offer them INH x 6-9 months and monitor their ALT/hepatic panel. I have seen 2 active TB cases since working at this clinic (1 year). We rather treat suspected LTBI than risk it developing into active TB.

 

 

Have you considered alternative therapies? I currently have a patient on INH-RPT, once weekly dosing x 12 weeks via Direct Observed Therapy (i.e., you or support staff watch them take the pills). A lot easier to get compliance and buy-in, IMO. This regimen was recommended to me by our Prev Med person, and is supported by literature. Just FYI.

[ventana]

Have you considered alternative therapies? I currently have a patient on INH-RPT, once weekly dosing x 12 weeks via Direct Observed Therapy (i.e., you or support staff watch them take the pills). A lot easier to get compliance and buy-in, IMO. This regimen was recommended to me by our Prev Med person, and is supported by literature. Just FYI.

 

that is pretty much the standard of care in correctional facilities these days

 

 

honestly I advocate for it as the general public standard...... 12 weeks is WAY shorter then 9 months!!

[Febrifuge]

I just wish people wouldn't be sent to us because someone read a PPD as "positive" when there was less than 10mm of redness and no induration whatsoever. A truly positive skin test can literally be read with your eyes closed, right?