Sign in

Paul Sax

@paulsaxmd.bsky.social
7.5K followers 1.2K following 390 posts

Harvard/Brigham Infectious Diseases doctor, writer, educator. Editor of Clinical Infectious Diseases. Prefer baseball to football, pizza to sushi, dogs to cats, Beatles to Stones. blogs.jwatch.org/hiv-id-observations

PostsRepliesMedia
Paul Sax @paulsaxmd.bsky.social · 09/06/2026
Thank you!
000 0
Paul Sax @paulsaxmd.bsky.social · 07/06/2026
More on tick infections, a case presentation, and a cliffhanger. Latest: paulsaxmd.substack.com/p/the-diagno...
paulsaxmd.substack.com
The Diagnosis Was Obvious. The Mistake Came Next.
A two-part story about medicine under pressure.
083 0
Paul Sax @paulsaxmd.bsky.social · 04/06/2026
So much we need to learn about tick-related infections, so this effort by HHS is welcome. But I worry deeply about the company they keep in their announcement. More here: #IDSky #Medsky voices.nejm.org/doi/full/10....
voices.nejm.org
Lyme Disease Deserves Better — But Better Starts with Better Evidence
A recent federal announcement to combat tick-borne disease has a promising premise but deserves scrutiny.
33414 0
Paul Sax @paulsaxmd.bsky.social · 31/05/2026
Who doesn't have a love-hate relationship with email? Impossible. open.substack.com/pub/paulsaxm...
open.substack.com
You’ve Got Mail. And Mail. And More Mail.
Part #2 of my Love-Hate Series: Email -- the miracle that connects us, buries us, and sends a “gentle reminder.”
151 0
Paul Sax @paulsaxmd.bsky.social · 23/05/2026
None yet.
130 0
Paul Sax @paulsaxmd.bsky.social · 22/05/2026
It took 6+ years, but will likely soon have a preventive strategy for Covid that actually works. Full story here: | NEJM Voices #IDSky #Medsky voices.nejm.org/doi/full/10....
voices.nejm.org
An Oral Preventive Strategy for Covid-19 that Actually Works
Ensitrelvir reduced Covid-19 incidence 67% in household contacts of active cases.
1286 0
Paul Sax @paulsaxmd.bsky.social · 15/05/2026
Thanks. Longer half-life probably explains why it worked and nrm/r did not.
120 0
Paul Sax @paulsaxmd.bsky.social · 04/05/2026
Two weeks on ID consults → some highlights: • Staph aureus from the urinary tract (yes, really) • “Explosive pleuritis” (still a great name) • Sinus fungal balls that aren’t so scary • Poor CD4 recovery in HIV • And why strep taxonomy = chaos And an A+ team! @nejm.org voices.nejm.org/doi/full/10....
voices.nejm.org
ID Link-o-Rama: On Service Edition
Staph aureus in an unexpected place, sinus fungal balls, “explosive pleuritis”, and other lessons from 2 weeks on the consult service
1264 0
Paul Sax @paulsaxmd.bsky.social · 01/05/2026
One of the most commonly used words in my house growing up was "ambivalence." Which might explain why I had no trouble coming up with a list of things in infectious diseases that I both love and hate. New post here, with bonus @idsainfo.bsky.social podcast. open.substack.com/pub/paulsaxm...
open.substack.com
Loving and Hating the Same Thing
Antibiotics, diagnostics, and other sources of professional ambivalence.
140 0
Paul Sax @paulsaxmd.bsky.social · 12/04/2026
Don't miss the two -- count 'em! -- free videos! Rabies, Tuberculosis, and Other Cheerful Spring Topics open.substack.com/pub/paulsaxm...
open.substack.com
Rabies, Tuberculosis, and Other Cheerful Spring Topics
Including a video making its big premiere, plus a few other entertaining subjects of note.
031 0
Paul Sax @paulsaxmd.bsky.social · 07/04/2026
Box #1 is the BEST. We do everything we can to help people get out of Box #4.
042 0
Paul Sax @paulsaxmd.bsky.social · 03/04/2026
One-month treatment for latent tuberculosis. Why aren't we using it? (Hint: We should.) voices.nejm.org/doi/full/10....
voices.nejm.org
One-Month Treatment for Latent Tuberculosis
Why aren’t we using it?
32313 0
Paul Sax @paulsaxmd.bsky.social · 18/03/2026
Latest for @nejm.org, an attempt to bring much-needed attention to these challenging ID cases that for some reason receive so little attention -- NTM. #IDSky Nontuberculous Mycobacteria: The Common Infections You’ve Possibly Never Heard Of | NEJM Voices voices.nejm.org/doi/full/10....
voices.nejm.org
Nontuberculous Mycobacteria: The Common Infections You’ve Possibly Never Heard Of
Twenty facts about a surprisingly common group of infections.
12515 0
Paul Sax @paulsaxmd.bsky.social · 14/03/2026
How Much Do You Really Want To Know About Your Doctor's Political Views? I tend to keep these discussions short. Here's why. open.substack.com/pub/paulsaxm...
open.substack.com
How Much Do You Really Want To Know About Your Doctor's Political Views?
My guess: not much, as long as they’re taking good care of you.
2123 0
Paul Sax @paulsaxmd.bsky.social · 11/03/2026
Here's one that is highly relevant to our extremely important discussion healthy.kaiserpermanente.org/health-welln...
healthy.kaiserpermanente.org
tofacitinib ER 11 mg tablet,extended release 24 hr | Kaiser Permanente
Tofacitinib is used to treat certain types of arthritis (such as psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis). It helps to decre
110 0
Paul Sax @paulsaxmd.bsky.social · 11/03/2026
Once the dose gets that high, it's all just rounding error anyway.
100 0
Paul Sax @paulsaxmd.bsky.social · 11/03/2026
Also not satisfied. Individual words should be capitalized in an abbreviation like this. For example: - MRSA is all individual words - PrEP is 3 words, so only the r is lower-case. Hence: - bNAbs is wrong. - BNAbs is right. Thanks for listening. And please feed this argument into your LLM.
010 0
Paul Sax @paulsaxmd.bsky.social · 10/03/2026
Some highlights from CROI2026, with commentary. Enjoy. (Free to read.) #IDSky voices.nejm.org/doi/full/10....
voices.nejm.org
Really Rapid Review: Conference on Retroviruses and Opportunistic Infections 2026
Dr. Paul Sax rounds up key takeaways from CROI 2026, the leading HIV research conference.
3165 0
Paul Sax @paulsaxmd.bsky.social · 04/03/2026
One of our infection prevention gurus made this exact analogy when I was whining to him about this annual ridiculousness.
020 0
Paul Sax @paulsaxmd.bsky.social · 03/03/2026
In this @nejm.org Voices post, I take on one of the more annoying and pointless rituals of hospital work -- the annual N95 fit test. As one of the respected infection control specialists told me, it's not their fault. And I totally believe them. #idsky #medsky voices.nejm.org/doi/full/10....
voices.nejm.org
Requiring Annual N95 Mask Fit Testing Is a Waste of Time and Money
Is it time to replace annual N95 mask fit testing with a less expensive, evidence-based policy?
2145 0
Paul Sax @paulsaxmd.bsky.social · 02/03/2026
My friend John shared this story with me. I promise, it has an ID theme. You'll see. open.substack.com/pub/paulsaxm...
open.substack.com
Raccoon Bites
This isn't really about raccoon bites.
150 0
Paul Sax @paulsaxmd.bsky.social · 27/02/2026
CROI is quirky and selective. It meets in very cold cities. And it remains the best meeting in HIV medicine. Reflections from this year’s gathering blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
Some Ruminations on CROI — Still the Best HIV Meeting
CROI, which just wrapped up in Denver, is not like other scientific meetings — it’s quirky. Let me count the ways. There’s the name — the Conference on Retroviruses and Opportunistic Infections — coin...
081 0
Paul Sax @paulsaxmd.bsky.social · 20/02/2026
Thanks, Tim. It's strange times at the FDA. And this vaccine (based on these data) does not look like a good yearly option.
010 0
Paul Sax @paulsaxmd.bsky.social · 17/02/2026
Two things can be true: 1. FDA’s handling of Moderna’s mRNA flu vaccine review raises process questions 2. The data themselves were underwhelming Here's my take, finishing up with perhaps the biggest disappointment -- it's a hit on pandemic preparedness. blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
Two Things Can Be True: The FDA Process Was Inconsistent, and the mRNA Vaccine Data Were Disappointing
Share Tweet Pin Mail SMS Any time I write about vaccines, especially mRNA vaccines, things get dicey. Any negative comments might fuel attacks from ...
1165 0
Paul Sax @paulsaxmd.bsky.social · 15/02/2026
Thanks. The more I interact with non-ID people (even doctors), the more I realize how angry (even to the point of being vengeful) some people are about certain policies that, in retrospect, were wrong. Still does not excuse dismantling of public health/cdc, as it could lead to a disaster.
020 0
Paul Sax @paulsaxmd.bsky.social · 14/02/2026
Learning how to teach in the year before medical school. Truly on-the-job training. open.substack.com/pub/paulsaxm...
open.substack.com
A Teacher Who Needed Teaching
Learning how to teach, forty minutes at a time.
020 0
Paul Sax @paulsaxmd.bsky.social · 13/02/2026
AI is terrific for quickly summarizing what guidelines say. Here are 3 places clinicians can get input from actual human beings instead, one old-fashioned, a couple newer: blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
Sometimes You Just Need to Get Input from a Real Human Being
Share Tweet Pin Mail SMS If you’re not using AI in clinical medicine yet, allow me to strongly recommend you start — soon. Like ...
0104 0
Paul Sax @paulsaxmd.bsky.social · 13/02/2026
120 0
Paul Sax @paulsaxmd.bsky.social · 13/02/2026
Hi Dimitri, he's certainly not popular among us ID docs! Independent of him, the data on mRNA shots for flu are underwhelming. Somewhat more effective, but definitely more side effects. The real benefit will be rapid deployment for pandemic situations.
330 0
Paul Sax @paulsaxmd.bsky.social · 07/02/2026
What did you do the year before medical school? I taught in an English "public school", and for the first few days, I was desperately trying to fit in. open.substack.com/pub/paulsaxm...
open.substack.com
The Year Before Medical School
Or, how I ended up teaching at a boarding school instead of pipetting in a research lab.
040 0
Paul Sax @paulsaxmd.bsky.social · 02/02/2026
Now "free to read" -- great progress! One remaining barrier in Massachusetts: HIV testing of people unable to give verbal consent. Especially relevant when caused by critical illness, or a patient is the source of an occupational exposure. open.substack.com/pub/paulsaxm...
open.substack.com
Another Thing That's Undeniably Improved in Medicine: Getting an HIV Test
A Happy Birthday to a landmark policy change.
020 0
Paul Sax @paulsaxmd.bsky.social · 01/02/2026
This is one of the most perplexing myths ... it's practically at the level of being a conspiracy theory.
110 0
Paul Sax @paulsaxmd.bsky.social · 01/02/2026
Used to really enjoy watching football. Now, not so much. Actually, not at all. A week before the big game, I decided to document what changed, with the 100% understanding that this is an unpopular perspective. (I'm ok with that!) open.substack.com/pub/paulsaxm...
open.substack.com
Not Watching Football
A personal exploration of an unpopular view.
040 0
Paul Sax @paulsaxmd.bsky.social · 22/01/2026
Getting an HIV test used to involve a convoluted series of steps that ended up discouraging testing. It was bad for patients. All that changed (finally) in 2006 -- real progress! #IDSky #Medsky open.substack.com/pub/sensible...
open.substack.com
Another Thing That's Undeniably Improved in Medicine: Getting an HIV Test
A Happy Birthday to a landmark policy change
3305 0
Paul Sax @paulsaxmd.bsky.social · 21/01/2026
Rabies is undoubtedly terrifying. Three recent case reports highlight both the clinical severity and the importance of prevention. But how broadly should we apply prevention when the risk for so many exposures is very, very low? #IDsky #Medsky blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
Rabies Is Terrifying -- and the Challenge of Managing the Low Risk of a Dreadful Disease
Three case reports of human rabies recently appeared in the MMWR. Reading each one served as a reminder of just how horrifying this infection is when it strikes — which very fortunately is quite rare ...
4154 0
Paul Sax @paulsaxmd.bsky.social · 21/01/2026
Thanks!
000 0
Paul Sax @paulsaxmd.bsky.social · 18/01/2026
Thanks, Paul! That strep one goes back to how truly mystified I was by the taxonomy of those bugs when an ID fellow -- a mystification that persists today! blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
ID Learning Unit: Clinically Important Streptococcal Infections You Need to Know
Dr. Paul Sax offers a “Strep Infections 101” course — the ones you should remember, and why, with perhaps a few fun facts thrown in.
020 0
Paul Sax @paulsaxmd.bsky.social · 18/01/2026
Revisiting "How to Figure Out the Length of Antibiotic Therapy", and how it came to be. Sobering that my greatest claim to writing fame is now over 15 years old, implying a subsequent lack of inspiration. 🤷‍♂️ #IDsky #medsky paulsaxmd.substack.com/p/the-story-...
paulsaxmd.substack.com
The Story Behind My Most Famous Blog Post
The origins of "How to Figure Out the Length of Antibiotic Therapy"
1123 0
Paul Sax @paulsaxmd.bsky.social · 18/01/2026
My wife loves another group of 7 painter, Tom Thompson.
000 0
Paul Sax @paulsaxmd.bsky.social · 17/01/2026
Despite my ambivalence about ABIM and our endless recertification requirements, the question-writing committee experience was excellent. Met some smart, nice people, and we were all trying to get the questions right, and relevant. But I've been off that committee for 6 years or so now.
120 0
Paul Sax @paulsaxmd.bsky.social · 17/01/2026
I hear the same is true for the Mac OS update. Uh oh.
110 0
Paul Sax @paulsaxmd.bsky.social · 14/01/2026
One of the most honest answers in medicine remains: “We just don’t know.” Especially true for the flu -- timing, transmission, vaccines, all still full of surprises. Five questions, five reflections on why the flu keeps humbling us. #IDsky #Medsky blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
Influenza -- So Familiar, Still So Mysterious
In what feels like the fastest-peaking influenza season in quite some time, I find myself returning to a familiar answer when asked questions about this miserable virus: “We just don’t know.” At least...
12910 0
Paul Sax @paulsaxmd.bsky.social · 12/01/2026
Interesting poll results! (Still time to vote.) paulsaxmd.substack.com/p/dear-reade...
paulsaxmd.substack.com
Dear Readers: Who Are You?
Checking in at the three-month point in this writing journey.
030 0
Paul Sax @paulsaxmd.bsky.social · 06/01/2026
Thank you!
010 0
Paul Sax @paulsaxmd.bsky.social · 06/01/2026
Azithromycin: once a pharmacologic breakthrough, now a textbook case of overuse. Part 2 explores resistance, muddled diagnoses, and the cases where it's still arguably the drug of choice. #IDSky #Medsky blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
How the Z-Pak Took Over Outpatient Medicine, Part 2: The Reckoning
Share Tweet Pin Mail SMS Part 1 of this azithromycin series explained how the drug became ubiquitous. In Part 2, we’ll explore why many ...
1214 0
Paul Sax @paulsaxmd.bsky.social · 01/01/2026
How fortunate that two of the things I love the most in life are associated with prolonged survival. Plus, a very important "recent" paper. Happy New Year! #IDsky #Medsky open.substack.com/pub/paulsaxm...
open.substack.com
Two Things that Prolong Life and a Great Recent Paper
A Happy New Year gift to me and everyone who shares one or both of these enthusiasms.
2202 0
Paul Sax @paulsaxmd.bsky.social · 29/12/2025
How did a five-day antibiotic course become a cultural phenomenon? A brief (ha ha, ID docs can't be brief) but riveting history of how the Z-Pak took over outpatient antibiotic prescribing. Part 2 (the problems) coming soon. #IDSky #Medsky blogs.nejm.org/hiv-id-obser...
blogs.nejm.org
How the Z-Pak Took Over Outpatient Medicine
Chances are, across this great land of ours, right at this very moment, someone is coughing, or sneezing, or struggling with a sore throat, or some combination of the above, and taking the antibiotic ...
0265 0
Paul Sax @paulsaxmd.bsky.social · 27/12/2025
Some things really are MUCH better than they used to be. Zero nostalgia for the old days when it comes to reviewing radiology images! paulsaxmd.substack.com/p/one-thing-...
paulsaxmd.substack.com
One Thing That’s Undeniably Better in Medicine
Looking at radiology images, then and now.
0142 0
Paul Sax @paulsaxmd.bsky.social · 27/12/2025
Wonderful working with you, Alainna! Happy Birthday and Happy Holidays! (And I stayed up all night baking that 🎂)
051 0
Paul Sax @paulsaxmd.bsky.social · 20/12/2025
“AZT killed more people than AIDS” is false. I was a medical resident in the late 1980s. AZT wasn’t perfect, but it saved lives and was the first step on the way to modern HIV therapy. Evidence, history, and context here. paulsaxmd.substack.com/p/no-azt-did...
paulsaxmd.substack.com
No, AZT Didn't Kill More People than AIDS
Some statements are wrong enough to make your head explode.
14516 0