An ongoing dialogue on HIV/AIDS, infectious diseases,
August 23rd, 2018
Eye Worm, MALDI-TOF, New Lyme Testing Approach, Dogs Fail as C. diff Testers, Uiyk (?), and More — A Summer Is Getting Shorter ID Link-o-Rama
A recent chilly spell here in Boston recalled a universal truth about aging — that summer seems to get shorter every year.
As far as I can tell in my unscientific poll of everyone who will engage with me on this topic, there are no exceptions to this rule. Everyone thinks summer is shorter than when they were kids, even though the calendar says summer lasts around 90 days — every year.
Why is the sun going down so soon? Is it already mid-August? No more free summer weekends? Didn’t it just get warm? Winter coats in catalogs? Back-to-school specials at the office supply stores? Halloween costumes at Costco? Summer is over already???? ARGHHHH!!!!
On to an ID Link-o-Rama, this one designed to accompany the late afternoon slanting sunlight that seems to say, “Too soon, too soon.”
- One in seven children born to mothers who acquire Zika during pregnancy has a birth defect. It’s clear Zika can be devastating to the developing fetus. What’s not so clear is what drives the highly unpredictable epidemiology, as the incidence is sharply down.
- Here’s a crystal clear review of what happens in a MALDI-TOF machine. Given the increasing use of this technique for pathogen identification, we might as well know what goes on inside that black box. Highly recommended.
- HIV virologic suppression rates in clinical practice have nearly tripled since the introduction of combination therapy in the late 1990s. 32% in 1997 to 86% in 2015 — that’s pretty, pretty good. The endlessly energetic Carlos Del Rio weighs in further here.
- A promising new class of antifungals has an absurdly weird-sounding name — ibrexafungerp. You read that right — and it’s pronounced “eye-BREX-ah-FUN-jerp,” in case you want to impress your friends. The always-brilliant PharmD Brandon Dionne had the best take on what this sounds like (yuck):
- The Tdap vaccine during pregnancy does not increase the risk of autism. Isn’t it sad that someone even has to do this study?
- Should we change the way we test for Lyme Disease? This alternative approach uses two different non-immunoblot methods, and apparently is more sensitive without adding to the false-positive rate. Certainly it promises to be faster (immunoblots seem to take forever). Sign us up!
- Good concise summary of what’s new (and what isn’t new) in Lyme. These two experts aren’t quite ready to adopt this new testing strategy, though they acknowledge its advantages. Regardless, interesting always to read their perspective.
- “My dog got his Lyme vaccine — why can’t I get one too?” If you’ve been asked that by one of your patients, the linked article from New York Times provides an excellent summary of the vaccine we once had, and why it’s no longer available.
- Another observational study shows no difference in clinical outcomes between ampicillin plus ceftriaxone versus ampicillin plus gentamicin for enterococcal endocarditis. No, it’s not a randomized trial, but when you consider that the amp plus ceftriaxone group had more renal disease and more comorbidities — biasing results against that group — you have to wonder why one would choose the aminoglycoside option, especially in the elderly.
- The earlier a resident does an elective in ID, the more likely they are to choose it as a specialty. Makes intuitive sense, but nice to see this documented. One of the rarely talked about changes to residency training since the introduction of work-hour restrictions is the reduction in opportunities to do subspecialty electives.
- These two Capnocytophaga canimorsus cases sure got a lot of attention. It’s fortunate these infections — linked to dogs, see the word “canine” in the name? — are very, very rare. Right Louie? That’s right, very rare — who’s a good boy?
- An artist experienced multiple parasitic infections after visiting the jungles of Gabon for several weeks, including the infamous Loa Loa eye worm. In the spirit of “Everything is copy,” he used the experience as inspiration for his art (featured on the cover of Emerging Infectious Diseases) — and almost netted the same level of media coverage as the capnocytophaga cases.
- Confirming a diagnosis of HIV while someone is on PrEP can be tricky. Here’s a guide to work through these sometimes “ambiguous” results. If you haven’t experience this clinical scenario yet — for example, someone on PrEP with a reactive HIV screen but other tests negative — prepare yourself to walk through these issues by reading this excellent paper.
- Maybe dogs can’t reliably sniff C diff after all. Tough Link-o-Rama for the doggies! From this excellent coverage of the published study: ““If there was a breakfast tray on that patient’s bed, Chase [the dog] was way more interested in the breakfast tray than he was in trying to find C. difficile spores,” … Another problem: “The dogs found it hard to pass a toilet without drinking out of it.”
- There are way too many measles cases in the USA, but things are really bad in Europe. Already there have been 37 deaths — all preventable with one of the most effective vaccines we have! This tweet from ID colleague Eli Perencevich comments astutely on the absurdity of this tragedy:
- Ibalizumab is effective in patients with multi-drug resistant HIV. This humanized IgG4 monoclonal antibody blocks viral entry, and is given as an infusion every two weeks. Notably, drug development of ibalizumab started around two decades ago, when we had many patients who could not achieve virologic suppression because of resistance — a situation uncommon today. That a phase III trial had only 31 patients and that the FDA approved it anyway demonstrates two things: 1) There are very few people who need this drug; 2) those who do need it really really need it — it can be life-saving. Trivia question — why is it called “ibalizumab-uiyk“?
- There are significant knowledge gaps about TB diagnosis and treatment among medical residents. Given how rare TB cases have become in the USA — especially in certain regions — these results are unsurprising, but still important. Mandatory ID consult for cases where TB is highly suspected? Certainly would advocate consultation when the diagnosis is confirmed.
- Fosfomycin susceptibilities are a mess. That’s the only conclusion one can draw from this interesting study of different testing methods, which highlights the difficulties of obtaining a reliable result outside of the cumbersome agar dilution method — a challenge that will become even more important when IV fosfomycin becomes available in the USA. (H/T to ID Journal Club for the link, see below for more information.)
- It’s been quite the season for Infectious Diseases and baseball. Two cases (!) of hand, foot, and mouth disease landed separate New York pitchers (one Yankee, one Met) on the disabled list. Not only that, Cleveland outfielder Leonys Martin sounds like he had sepsis or toxic shock syndrome. Speedy recovery!
Three more items before you head back to beach.
- Shout out to the excellent ID Journal Club, where Dr. Nicolás Cortés-Penfield summarizes recent ID literature in clever, concise snippets. He’s been doing it for around a year — may he long have the energy to continue!
- On The OFID Podcast, PharmD extraordinaire Dr. Susan Davis joins me to highlight the critical role ID pharmacists play in improving patient care.
- On The Curbsiders Podcast, I spend a bunch of time talking about tick-related infections, in case you can’t get enough of these critters.
Hey, next week I’m on vacation — so summer can’t be over quite yet, right?