Another round of Daylight Saving Time. I came across a new article suggesting that potential harms of DST depend on your individual chronotype, or, more simply, whether you are an owl or a lark. I definitely fall into the lark category. More on this later, but let's dive into what's been happening in pediatric infectious diseases the past week.
New IDSA Laboratory Test Guidelines
Just out is an updated guideline from the Infectious Diseases Society of America. It might be my favorite guideline of all time, but at 244 pages I recognize it's not for everyone. Let me mention a couple items that I notice some frontline healthcare providers may not know about but are important to avoid misleading test results (a garbage-in-garbage-out scenario).
First concerns the use of swabs, starting on page 8 of the pdf guideline document. Always use a swab for sampling throats, conjunctiva, superficial wounds (aerobic culture only), some nose, nasopharynx, and vaginal testing, and sometimes in special circumstances related to institutional- or manufacturer-related instructions for the product. Never use a swab for surgical tissue - submit the tissue itself making sure it doesn't dry out before processing. The same applies for "respiratory fluids and secretions, endophthalmitis and keratitis, nasal sinus, otitis media, biopsy, abscess fluid, fungal and acid-fast bacilli specimens, formed stool, epiglottitis, diarrheal illness, and when anaerobes are suspected opt for tissue or fluid in anaerobic transport... Never submit a swab for analysis that has been dipped into a fluid or exudate. Send an adequate volume of the fluid or exudate instead." There's also an in-between situation where larger volume sampling isn't feasible, such as with an open wound (at least obtain a needle aspirate of leading edge).
The second pertains to urine specimens, the bane of my existence when consulting on possible UTI based on specimens that have sat around for considerable time before processing, such as placed in a lab collection box in an outpatient setting. Some key points, starting on page 119: "Urine collected for culture should not be kept at room temperature for more than 30 minutes. Hold at refrigerator temperatures or utilize a preservative tube if not processed by the laboratory within 30 minutes." The authors also mention the perils of relying on urinalysis because techniques have not been standardized and often require subjective interpretation. Especially if you are dealing with a child with possible UTI, obtain a good mid-stream voided or catheterized urine specimen and, again, don't let it sit at room temperature too long before analysis.
Different considerations arise when sampling urine for sexually transmitted infection - here, the first portion of urine voided is best for detecting pathogens by nucleic antigen amplification testing.
Speaking of Throat Swabs
The biggest problem in diagnosis of streptococcal pharyngitis is performing throat testing in children highly unlikely to have streptococcal pharyngitis. In this setting, a positive result is much more likely to represent a clinically-irrelevant carrier state and result in unnecessary antibiotic exposure for the child. Some heavy hitters in the group A streptococcal world published a review on this recently, but unfortunately it is not available without subscription to the journal. The authors describe differences in GAS testing between the US and Europe, compare and contrast rapid antigen detection and NAAT testing, and again mention situations where testing should not be performed: children less than 3 years of age unless known exposure, children with signs of viral infection including cough, runny nose, or hoarseness, and absence of "bona fide" clinical suspicion for strep throat if you use a clinical scoring system such as Centor or McIsaac.
Nirsevimab Worked Liked We Hoped
Nirsevimab effectiveness was 90% in preventing hospitalization for RSV infection in infants during their first RSV season, according to CDC data on 699 hospitalized infants. This is actually at the upper end of the confidence interval from prior clinical trials.
AI for Otitis Media
I seem to be on a track of personal banes of my existence as a consultant; misdiagnosis of acute OM is near the top. Although I don't see any of us being replaced by artificial intelligence anytime soon, a new report has some glimmer of hope that it might help us with AOM. It uses a not-yet-available iPhone app with an otoscope; you can use voice to control when to take a photo. Watch the video (at the link to the article, not in the screenshot below) to get an idea of what's involved. It's not nearly ready for prime time, but stay tuned.
Is Covid a Risk for Development of Autoimmune Rheumatologic Inflammatory Disorders?
This study of millions of adult patients from Korea and Japan utilizing a claims database would suggest that it is, with adjusted hazard ratios around 1.25 - 1.3. So far this is just an association and does not determine causality. Also, genetic risks for autoimmune disorders differ in Asian versus US populations (think Kawasaki Disease), so the results may not be broadly applicable.
Influenza is Still With Us
I've officially retired my WRIS (Winter Respiratory Infection Season) section. Really we're only waiting for flu to wind down, though we still have too many covid hospitalizations and deaths. Here's the most recent Fluview map, looking a little more encouraging:
In the meantime, the FDA VRBPAC met on March 5 to officially recommend trivalent vaccines for next fall. The disappearance of the B/Yamagata lineage means we won't need a quadrivalent vaccine as in past years. Next up is CDC/ACIP recommendation in June.
Medical Injustices in the Past
It was painful for me to read, but I highly recommend the NEJM series highlighting medical injustices and biases perpetuated in its publications. The current article is about eugenics. Apparently there were a few voices trying to speak up against these practices in the early part of the 20th century, but they were drowned out by the majority, many of them physicians. You don't need a subscription to the journal for this series.
My Inner Lark
On a lighter note, I was delighted to learn that I might not be at such high risk for adverse events of Daylight Saving Time. A recent study looked at the effects of the DST change on sleep and work productivity in 155 full-time workers in Germany utilizing survey methodology. The effects varied with individual chronotype; that is, the "owls" are those that tend to stay up and wake up later than "larks," the early to bed and early to rise group. There's actually a tool to determine chronotype! The study found that us larks are less affected by the shift to DST.
Lots of evidence exists that the DST shift is associated with harmful effects, from medical illness to car crashes to work productivity. However, this is an extremely messy phenomenon. We have good evidence that the shifts are associated with poor circadian rhythms, a biologic plausibility for harmful outcomes, but only an epidemiologic association with these bad outcomes. With too many factors that can't be controlled or accounted for, probably the only way we will know if DST is bad is if the bad outcomes lessen when we quit using DST. I recall 2 prior instances where an epidemiologic association was likely confirmed to be causal: the association of aspirin use with Reye Syndrome in children, and the association of infant sleeping position with Sudden Infant Death Syndrome. The aspirin industry fought against the concept, but Reye Syndrome essentially disappeared when aspirin use for symptom relief in young children ended. SIDS rates plummeted with the Back-to-Sleep programs.
I don't recall ever seeing a lark, but apparently a subspecies of horned lark inhabits Maryland. I guess I'll need to rise early to spy one.
