Many thanks to Dr. Danny Toub, a family physician, teacher, and public health professional-- who so often bridges the impossible gaps that exist between individual patient care conundrums and public health. While this bridge may seem intuitive, it is often rickety and not always clear how to begin to build it-- look to Dr. Toub, though, he always shows us the way.
A recording of his presentation is available HERE.
This week's topic was Tuberculosis (TB), a global behemoth; the original and ever-present airborne illness that still kills 1.4 million people worldwide per year, more than HIV/AIDS While we sit in the middle of a harrowing COVID-19 Pandemic and the words N-95 have become every day jargon, TB is still global problem. And while we have made great progress in the US with TB eradication, TB still unnecessarily killed 542 Americans in 2018, 200 of which were right here in California.
TB, much like COVID, disproportionately affects people who are living in poverty, people of color, and those who have less access to stable housing and health care services.
What is our responsibility as primary care providers?
- Screen ALL patients for TB Risk
- Screen HIGH RISK patients with a Tuberculin Skin test (TST) or interferon gamma release assay (IGRA)
- Treat Latent TB infections (LTBI)
- Report to Public Health any active TB cases and/or any LTBI in children or recent converters (<2 years)
- Oh, and don't forget to have TB on your ddx for other acute/subacute illness presentations!
If we break that down,
1) Screen ALL patients for TB Risk using the California TB Risk Assessment Tool which can be found
HERE and is pictured below as well.
Remember to
AVOID testing low risk folks for LTBI (this form alone counts as a screen!) and if you have limited resources, prioritize those who are most likely to convert from LTBI to active TB. Key risk factors include being foreign born/immigrant from certain regions, immunosuppression, and those who have been in close contact with someone with TB.
Important additional risk factors include, recent conversion, substance use disorder, patients with DM, patients with CKD, those with autoimmune conditions, people who smoke, people with cancer, and more.
The point of screening is to prevent a future conversion to active TB by treating people before they get sick. Low risk patients have ~10% lifetime risk of converting. Higher risk (e.g. people with diabetes) have ~ 30% lifetime risk, and highest risk folks (e.g. HIV + LTBI) have a 7-10% per year risk of converting.
2) Screen HIGH risk patients with TST or IGRA. The best TB test depends on your pretest probability. Here is a good cheat sheet.
#Note that the CDC no longer recommends annual TB testing for healthcare workers!! Official recommendations released in 2019 are available
here and recommend a risk based technique. Maybe that means YOU don't need that annual TST!
*TST: tuberculin skin test, **IGRA: interferon gamma release assay (often referred to as quantiferon gold). There is limited data in IGRA in children <5. IGRA are more specific than TST in pts with a history of a BCG vaccine.
+Remember, a negative IGRA or TST does NOT rule out active TB (you need sputum!)
3) Treat LTBI infection. Treatment for LTBI has been shortened and simplified over the last decade. It does not involve routine lab work (except in high risk folks) or directly observed therapy (DOT).
Dr. Toub recommends this handy
LTBI pocket card to help simplify your decision-making and treatment regimen planning. The image below to too small to actually read, but follow the link for specifics on indications, completion criteria, considerations, etc.
Briefly, prior to initiating LTBI treatment, you want to be sure to r/o pregnancy, check for pre-existing peripheral neuropathy (which can be a side effect of tx), screen for liver disease risk factors (e.g. alcohol use disorder, NASH, HCV).
Baseline LFTs are only indicated for patients with HIV, known liver disease, regular alcohol use, pregnancy or < 3 months postpartum, and other risks for liver disease.
And, Dr. Toub reminded us to remind your patients that EVERYthing will be orange (sweat, tears, and urine). Also be sure to check for drug drug interactions on any tool that you use for this purpose, as there are many.
4) Report to
SoCo Public Health any active TB cases and/or any LTBI in children or recent converters (<2 years).
5) Oh, and don't forget to have TB on your ddx for other acute/subacute illness presentations! Remember TB can show up just about anywhere.
For local assistance, you can utilize the
Sonoma County TB Control Guidelines, which you can find at the
bottom of this webpage. And if you ever have any TB questions, reach out to our local TB Control program at 707-565-4567.
And, finally, a list of trusted resources from Dr. Toub:
The ANCHOR Trial, published in NEJM 2022 was a multi-site RCT that showed that, YES, screening at risk populations does work to prevent anal cancer. Primary outcome: anal cancer. Test subjects: Men with HIV age >35. Study found 9 anal cancers in the treatment group (those screened>> HRA>> treatment) vs. 21 cancers in the observation group. This equates to a 60% decrease in anal cancer.
