Regarding TST and IGRA for remote infections… The TST is not better in it’s naïve state at such detection – that’s why the 2-step TST is done. One primes the immune system’s memory with an initial TST and
then tests it “for real” with the 2nd step the following week.
With the blood assay IGRA alone we do not have that ‘primer’ of the 1st TST to boost the immune system if the infection is very remote. For that reason, occasionally, I have placed a TST and then
ordered an IGRA afterwards.
You’ll probably all remember the debate about “boosting” that was shown to happen sometimes when a TST is done withing 3 months of an IGRA. Looking at Bob Belknap’s paper
https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2009.179.1_MeetingAbstracts.A4101 the boosting that occurred was in people who had risk factors for TB and likely truly had latent disease. Thus, the TST before IGRA could be a good technique
in a case where the diagnosis is in question.
On the other hand, TB does become quiescent, walled off, and even cleared in some cases. The utility of boosting a very latent infection is not clear. We know that persons with a granuloma by CXR are more
likely to reactivate their TB than those with clear CXRs, and that recent TB infections are more likely to reactivate. Whether we should be chasing distantly remote disease with TST + IGRA is of questionable medical benefit.
Regarding travel, I agree with MS: “The travel question on hire can be informative if their baseline test is
positive. On an annual basis, it just serves to prompt them to consider testing, if you are surveying people without a prior positive test who are not required to get annual testing for their job role. But you may just be surveying people with known untreated
LTBI in which case it is not useful.”
Regarding immunosuppression, if one’s patient has planned immunosuppression, there should be a TB test before initiating that medication regimen but that would be done by the MD who is prescribing the immunosuppressive.
A reminder via education that they could be at more risk for getting TB after such initiation is a good idea.
Best regards 😊 lol,
Wendy
From:
MCOH-EH <mcoh-eh-bounces@mylist.net> on behalf of Swift, Melanie D., M.D., M.P.H. via MCOH-EH <mcoh-eh@mylist.net>
Date: Thursday, February 9, 2023 at 10:36 AM
To: MCOH-EH <mcoh-eh@mylist.net>
Cc: Swift, Melanie D., M.D., M.P.H. <Swift.Melanie@mayo.edu>
Subject: Re: [MCOH-EH] [EXTERNAL] Re: Re: Re: TB screening question
Well said, Sally. The issue of immunosuppression and travel or other nonoccupational risks really should be addressed in annual training where everyone will be reminded. With TB rates on the rise around the
globe, these are important reminders for everyone.
Thanks,
Melanie
From: MCOH-EH <mcoh-eh-bounces+swift.melanie=mayo.edu@mylist.net>
On Behalf Of Sally Foster-Chang
Sent: Thursday, February 09, 2023 12:14 PM
To: MCOH-EH <mcoh-eh@mylist.net>
Subject: [EXTERNAL] Re: [MCOH-EH] Re: Re: TB screening question
There is clearly a burning need for more research on when and when not to re-test. When we initiated an IGRA based program, we re-tested a number of our prior positive PPDs employees. Most did test positive,
but a few did not. One employee had worked in a Leprosy clinic and had a history of a positive PPD and a reaction to prophylactic treatment for latent TB (which meant the treatment was never finished). Leprosy is one of those diseases that can cause a false
positive PPD and may also cross-react with an IGRA. Apparently, Leprosy can be cleared by the immune system and not result in symptoms. This employee's IGRA was negative, but the employee was still placed in the "group to watch".
Some of the current research suggests PPDs might be better at identifying remote TB infections, while IGRAs might be better at picking up more recent infections (if you need references, let me know). There
are also cases where individuals appear to spontaneously clear TB or revert to negative after treatment. Sometimes doing more testing can just blur the picture. It is indeed a delicate balance. As several of my esteemed colleagues have very appropriately
advised, documentation, risk assessment, symptom screening and annual TB education are essential!
On Thu, Feb 9, 2023 at 12:36 PM Swift, Melanie D., M.D., M.P.H. via MCOH-EH <mcoh-eh@mylist.net> wrote:
Agree these specific questions can pose quandaries, if asked on an annual symptom questionnaire. The immunosuppression question is helpful if you have tested them and they have a positive test, declined LTBI treatment, and are now immunocompromised which might change their decision to accept treatment. We incorporate this concept in an annual reinvitation to get treatment for everyone with untreated LTBI.
The travel question on hire can be informative if their baseline test is positive. On an annual basis, it just serves to prompt them to consider testing, if you are surveying people without a prior positive test who are not required to get annual testing for their job role. But you may just be surveying people with known untreated LTBI in which case it is not useful.
We use all these questions in the baseline screening, but we actually adapted our annual questionnaire to remove these questions except in states where public health depts require either symptom survey for everyone or require these questions specifically for annual surveys. Do check with your state TB control program before adapting the survey.
Melanie
From: Enass Awad <umhaneen@gmail.com>
Sent: Thursday, February 09, 2023 11:14 AM
To: MCOH-EH <mcoh-eh@mylist.net>
Cc: Swift, Melanie D., M.D., M.P.H. <Swift.Melanie@mayo.edu>
Subject: [EXTERNAL] Re: [MCOH-EH] Re: TB screening question
Hi everyone:
Tagging along on the TB topic but about symptom screening questionnaires for annual TB surveillance.
When employees answer “ yes” for history of travel to a TB prevalent country for one month or more , do you require them to do a test if they are asymptomatic?
Same inquiry about what do you do if the employee answers yes to the “ do you have current or planned immunosuppression !
Our hospital currently tests employees if they said yes to the travel question whether or not they are symptomatic which am not sure is necessary ? Any one aware of what data supports this ? With the immune suppression we are testing only those who are symptomatic !!
Thanks much ,
Enass Arahman, MD, MPH,FACOEM
Medical Director Employee Health Services
UC Davis Health
Sacramento, CA
On Wed, Feb 8, 2023 at 12:10 Swift, Melanie D., M.D., M.P.H. via MCOH-EH <mcoh-eh@mylist.net> wrote:
Dr. Thrasher, attached is the NTCA-ACOEM collaborative guidance document on TB testing and treatment in healthcare personnel. The preplacement evaluation recommendations for HCP with a prior positive TB test begin at the bottom of page e358.
Recommendations are essentially the same for prior treated LTBI and prior treated active TB. Document the dates and confirmation of completed treatment. For active TB they should have a clearance document from their public health department at the completion of therapy. A symptom screen would be recommended, but as long as she is asymptomatic and you have documentation of her prior positive IGRA and/or TST at the time of her original diagnosis, documentation of complete treatment and clearance of the active infection, then there really is no testing or imaging recommended. The key will be obtaining that documentation. If she has none, then as Sally recommends you could get an IGRA now (likely would be positive) and follow your usual clearance process. You can do a single view CXR with abdominal shielding, should records be unavailable and you need to exclude active TB. If you have the records though, no need to image her unless she is symptomatic or her treatment wasn’t complete.
Melanie
Melanie Swift, MD, MPH
(she/her)
Vice Chair, Division of Public Health, Infectious Diseases and Occupational MedicineMedical Director, Mayo Clinic Physician Health Center
Associate Medical Director, Occupational Health Service
_______________________________
Mayo Clinic
200 First Street SW
Rochester, MN 55905
From: MCOH-EH <mcoh-eh-bounces+swift.melanie=mayo.edu@mylist.net> On Behalf Of Sally Foster-Chang
Sent: Wednesday, February 8, 2023 11:20 AM
To: MCOH-EH <mcoh-eh@mylist.net>
Subject: [EXTERNAL] Re: [MCOH-EH] TB screening question
I’d do an IGRA. At least you would have a baseline.
On Wed, Feb 8, 2023 at 12:02 PM dennis thrasher via MCOH-EH <mcoh-eh@mylist.net> wrote:
Any recommendations for a new-hire nurse applicant? She is pregnant and
has previously been treated for active TB.
Thanks.
Dennis Thrasher, MD, MPH
sunnyside@dakotacom.net
520 247 1397
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Sent from Gmail Mobile
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The MCOH-EH List has always been moderated by members of the ACOEM Medical Center Occupational Health Section. It is currently moderated by Joe Fanucchi MD FACOEM.
List membership is free, but only subscribers may post to the list.
To post send messages to: mcoh-eh@mylist.net
To become a subscriber, or to change your subscription options (turn off email while you're on vacation, etc): http://www.mcoh-eh.net
MediTrax / Occupational Health Systems, Inc. provides financial support to ensure the list remains a free resource for the occupational health community.
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List archives (public): http://mylist.net/archives/mcoh-eh/
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Send administrative requests to: drjoe@meditrax.com
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When replying to a message, PLEASE delete all footers, and all messages to which you're NOT replying.--
Enass Awad A/Rahman,MD,MPH
Department of Occupational Medicine
Mercy Medical Group
3000 Q Street
Sacramento,CA,95816
Tel: 916-733-3390
"We can enrich the world if we choose to embrace our similarities; we can destroy the world if we choose to emphasize our differences."---------------------------------------
The MCOH-EH List has always been moderated by members of the ACOEM Medical Center Occupational Health Section. It is currently moderated by Joe Fanucchi MD FACOEM.
List membership is free, but only subscribers may post to the list.
To post send messages to: mcoh-eh@mylist.net
To become a subscriber, or to change your subscription options (turn off email while you're on vacation, etc): http://www.mcoh-eh.net
MediTrax / Occupational Health Systems, Inc. provides financial support to ensure the list remains a free resource for the occupational health community.
---------------------------------------
List archives (public): http://mylist.net/archives/mcoh-eh/
---------------------------------------
Send administrative requests to: drjoe@meditrax.com
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When replying to a message, PLEASE delete all footers, and all messages to which you're NOT replying.