Paul Sax

Since launching the HIV and ID Observations blog, Paul Sax, MD, clinical director of the Division of Infectious Diseases, has written hundreds of posts about infectious diseases (ID), medicine in general and various other not-so-medical topics. He recently celebrated the tenth anniversary of his blog, which has covered everything from baseball to HIV to wardrobes to the Zika virus. The blog has generated more than 2 million page views, with readers from all over the world.

In this abridged Q&A, Sax shares more about the project’s origins and what he enjoys about blogging. Read the full interview at

How did you begin the blog?

PS: When writing on the internet exploded around 15 to 20 years ago, I was reading an increasing amount of incisive, entertaining commentary about baseball, since baseball is one of my passions. To give you an idea about how long ago this was, this was back when ads used to include the phrase, “Visit us on the web!” with their URLs. Since I’m also very passionate about my field of medicine, I wondered if I could write something similar to this educational and fun baseball writing, only shifting the topic to infectious diseases.

I offered the idea to the Massachusetts Medical Society, the publishers of The New England Journal of Medicine. Fortunately for me, they agreed. Let the record show that they are much more famous for their flagship journal than my blog, but I’m happy to bask in in their glory.

How would you describe the tone of your blog?

PS: The tone is casual. I try to make it sound like a conversation rather than what’s published in medical journals. I always enjoy reading authors who take the work out of reading.

Plus, my family all knows that I’m a frustrated comedy writer, and the blog has provided a nice outlet for me. In college, I was one of the editors of the Harvard Lampoon, which is a training ground for many successful comedy writers. Yes, pursuing a career as a comedy writer would have been a very different path from medical school, and it honestly crossed my mind at the time. I don’t regret the choice I made. Medicine in general and ID in particular have formed a fascinating and rewarding career for me. But at least with the blog, I get the chance to be funny. Or at least to try to be funny.

Are there posts that have been particularly popular?

PS: I wrote a post about the greatest infection risks for people who inject drugs. I think the public perception remains that HIV and hepatitis C are the two biggest risks. But, in fact, they really aren’t; we have effective treatments for both of those infections, even a cure for the latter. So, I wrote about my experience having seen so many previously healthy young adults in the hospital with life-threatening bacterial infections and set it in the context of a discussion with my college-aged daughter. The post touched a nerve. It received widespread attention.

Other than that, posts about how doctors dress seem to be extremely popular. I also go to all the major HIV conferences and summarize them, and these summaries are broadly distributed on social media.

Do you engage in dialogue with your readers?

PS: Absolutely, and I enjoy it – the people who follow the blog seem to be a fantastic community, with a high proportion of ID and medical nerds. One of the early decisions we made was to have a moderated comments section, which means either the editor at Massachusetts Medical Society or I review the comments before they are published.

The geographic distribution of my readers has been a wonderful surprise. I wrote a post recently about when my dog was attacked at the local park by another dog, which had almost nothing to do with infectious disease. I was recently at the International AIDS Conference in Amsterdam, and an infectious diseases specialist from Mexico came up to me and said, “I’m so sorry about your dog.”

Is your dog feeling better?

PS: He’s fine now. I’m the one who’s still a wreck!