Travel Notes: Infectious Disease updates from an Emergency Medicine conference.

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I attended a major national emergency medicine conference with around 6,000 other ER doctors this week in Las Vegas. It was nice to be back among my own kind and see old friends and colleagues from all over the place, many of whom I had not seen in a long time.

This conference had a whole program of “continuing medical education” for physicians. I was pleased to have been asked to deliver an hourlong talk covering the latest updates in infectious diseases research and related news. As you know, I’m rather interested in this area, so it wasn’t a stretch to put the talk together. Naturally, I spent a lot of time on Covid-19 updates, but I resisted the temptation to spend the entire hour on Covid. I managed to mix it up a bit and include a variety of topics.

While the talk was directed at practicing emergency physicians, I wanted to share some highlights that may be of interest to you. Some of this information may be familiar to Inside Medicine readers, but there’s a lot new too…

Let’s dive in!

Current outbreaks.

• H5N1 bird flu. While over 100 million poultry, 10,000 wild birds, and 237 dairy herds have been affected by H5N1, only 14 human cases in the US are known. There have been zero fatalities and mostly mild illness. The concern is that if the virus mutates or picks up new genetic material (by intermingling with other flu viruses), things could get bad quickly, especially with fall and winter coming.

• Mpox. The WHO has declared mpox a “public health emergency of international concern” (“PHEIC”) twice since 2022. The current PHEIC is notable because it is being caused by a different strain of mpox than the last one. The current strain (clade 1b) is thought to be more deadly than the previous one (clade IIb), though I’m not certain we know this for sure. It may boil down to the demographics/epidemiology of who is getting infected in each outbreak. As ever, when assessing potential outcomes, patients’ risk factors are often as or more important than the diseases themselves.

Covid-19 research.

• As of 2023, Covid-19 is no longer in the top ten leading causes of mortality in the United States, as it was in 2020, 2021, 2022, and 2023 (when it fell to 10th). Currently, Covid-19 is the 14th leading cause of death for 2024. Some of this may reflect decreased awareness of cases, as universal testing has gone to the wayside, meaning that some cases in which Covid-19 played at least some role in a death are now likely going undetected. However, a lot of it is due to our increasing immunity to the pathogen, thanks to vaccines and, less ideally, infections.

• Paxlovid and symptoms. Paxlovid has never been shown to reduce symptoms of Covid-19 in a randomized controlled trial. Pfizer’s placebo-controlled randomized clinical trial on symptom relief failed to find a benefit, a study which came out earlier this year.

• There’s hope! A recent study (a randomized controlled trial) of a newer drug called simnotrelvir actually did reduce the time it took for patients to have a sustained reduction in symptoms.

• Long Covid updates. The National Academies of Sciences, Engineering, and Medicine came out with an updated definition for Long Covid earlier this year. The new definition is very broad and inclusive. Back when NASEM was working on its updated definition, I addressed their workgroup at a meeting of its experts convening in Washington DC. More or less, I urged the group to avoid a definition that was too broad. Why? Because while a broad definition would indeed be inclusive and potentially identify more patients, it would also be less specific, and therefore make it harder for researchers to study the problem in the search for effective treatments.

Other diseases of interest.

• HIV prophylaxis. People at high risk of contracting HIV can virtually eliminate their risk by taking antiviral medications collectively known as PrEP (pre-exposure prophylaxis). One difficulty is adherence. Like with any medication, people have trouble taking it consistently, which reduces effectiveness. That’s why a study this year showing that a twice-yearly injection eliminated HIV transmission in women was such a blockbuster. The issue now is affordability. However, there’s recent good news on this—as the drug manufacturer has agreed to make the drug available royalty-free through generic manufacturers in resource-limited nations. This is great news.

• Antibiotic stewardship in pneumonia. When patients come down with pneumonia, they often need antibiotics. The more medical problems a patient has, the more likely we are to “pull out the big guns,” choosing options that treat less common but dangerous bacteria. The problem with that is that this breeds resistant bacteria in precisely the patients who are vulnerable to serious consequences from them. So, there’s some research that aims to decrease how often we use important antibiotics in our toolkit so that we don’t render them useless due to resistant superbugs. A recent observational study showed that for a particular kind of pneumonia, patients who did not receive antibiotics that work against an even more extended range of germs than the usual ones had the same mortality rate. On top of that, those patients were spared from the feared complications of those antibiotics—an opportunistic parasite infection called C. diff that takes over when a newly bacteria-free environment (thanks to those antibiotics) permits it.

• Spinal taps. When we are worried that a patient might have an infection or inflammation in the brain, we perform a “lumbar puncture” (also known as a spinal tap) to get a sample of the fluid that surrounds the spinal cord and brain. Depending on the findings, we might treat them for a number of dangerous conditions. Well, a very interesting study found that in patients who were eventually found to have either an infection or auto-immune inflammatory condition in the brain, some of the initial test results (from the sampled fluid of the spinal tap) are normal around one-quarter of the time. That could falsely reassure doctors that things are fine, when they are not. That’s scary because we can’t miss 25% of these cases. For me—and many physicians—if I’m worried enough about encephalitis or meningitis (infection of the surrounding layers of the brain and spinal cord) that I’m doing a spinal tap, I go ahead and initiate broad treatments that cover a lot of bases. If the final test comes back negative later on, the inpatient teams can stop the antibiotics, antivirals, or other treatments that I initiated in the ER.*

Those were just some of the studies I covered in my talk. It was a great opportunity to take stock of some recent progress in the field and I enjoyed the session. (Having a nice and engaged audience at 8:30am was a pleasant surprise too). Hopefully I’ll get to do another talk like this again sometime.

*Thanks to reader Howard Bessen for pointing out an error I made in my description of this in a previous version of this article.

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