We seem to have settled back into the good old days of infectious diseases and outbreaks, always something going on but at least nothing on the level of the past 3 years. Certainly we'll see an upswing in covid sometime in the coming months, but in the meantime I will try to return this blog to something approaching normality.
Short Antibiotic Course for Community-Acquired Pneumonia in Children
A group of Chinese investigators, working with McMaster University experts in evidence-based medicine, reported a meta-analysis looking at treatment duration in randomized controlled trials of antibiotics for pediatric CAP. Let me say from the start that this study is an excellent example of how to perform a high quality meta-analysis. I came to that conclusion before I realized that the McMaster group was involved, in particular Gordon Guyatt who is one of the world's leading researchers in EBM methodology.
The group defined short-term treatment as 5 days or less and found that shorter duration did not seem to alter outcomes compared to longer treatment. Here is one of the Forest plots looking at treatment failure of 3 or 5 days of antibiotics versus 5, 7, or 10 days:
This is one of many forest plots (also known as blobbograms, don't you love that!) including multiple subgroups that together provide reassurance for short-course therapy for CAP. The authors spent considerable time looking or sources of potential bias, somewhat difficult because each of the included studies had differing definitions and methodologies.
The children in these trials had relatively mild CAP, so the results shouldn't apply to those with more severe CAP. Also, It is likely that a large proportion of study subjects had viral infections. As the authors mention, "... it is usually extremely difficult to distinguish between viral and bacterial CAP." Still, the takeaway message should be to consider short (or no) antibiotic therapy for mild pediatric CAP.
Human Papillomavirus Transmission from Pregnant People to Their Neonates
Investigators from multiple Canadian institutions reported a prospective cohort of 1050 pregnant persons and their newborns with regard to HPV infection rates in the mothers, along with HPV detection in placentas and rates of positivity in their infants followed for a 6-month period. Note that the study recruited mothers early in pregnancy in the time period of 2010-2016. The bottom line was that 40%(!) of mothers had detectable vaginal HPV, but only 92/860 (10%) of tested placentas were positive. Detection of HPV from any site (conjunctival, oral, pharyngeal, genital) in newborns at birth or at 3 months of age was positive in about 7%, but no infant was positive at 6 months of age at any site.
This is a nice study and is somewhat reassuring that HPV transmission from mothers to infants in utero or perinatally is not a large problem. Of course, having seen innumerable infants with tracheal HPV, I can vouch that even an uncommon event like perinatal HPV transmission can result in severe consequences.
'Demic Doldrums
Please excuse my stretch to find an alliteration for this topic. Until we see the next covid wave, I liken this time to the doldrums. If you, like Jack Aubrey*, command a ship in the early 19th-century British Navy, the doldrums are to be feared; an absence of wind means your ship is stalled. It's not easy to row a 3-masted vessel in the ocean. However, a pandemic doldrum is a good thing. I'll include some 'demic doldrum postings as a semi-regular feature in upcoming blogs.
This past week had a few covid highlights worthy of mention. First, investigators at the University of Warsaw, Poland, reported 3- and 6-month echocardiographic evaluations in 172 consecutively diagnosed children with Multisystem Inflammatory Syndrome in Children. All of the subjects were asymptomatic from the time of their MIS-C hospital discharges. Results were quite good, even in those with initially severe cardiac involvement.
Along similar lines, we have some new data on safety of the Pfizer covid vaccine with numbers on myocarditis/pericarditis rates. It's a US commercial claims database analysis from the FDA and other organizations (but no contribution from Pfizer, so less chance of bias) and covers 3 million children 5-17 years of age. It looked at rates after both the primary series and after a third vaccine dose. Out of 20 different adverse events monitored, only myocarditis/pericarditis showed a safety signal but just in children in the 12-15 and 16-17 year age groups. The average rate for this complication was 39.4 events per million vaccine doses and tended to occur about a week after the primary series. The investigators were able to perform medical record reviews on only a subset of the events to verify diagnoses. This study is an example of the type of post-marketing data we need to continue to follow vaccine recipients for adverse events and is encouraging that nothing new is turning up so far.
We also have evidence of progress on the long covid front, more appropriately termed PostAcute Sequelae of COVID (PASC). We now have a better case definition. That may not sound like a big deal, but for something this complicated a good case definition is essential to figuring out diagnostic and management trial design and best strategies. A group from multiple institutions in the US developed a scoring system based on study of almost 10,000 adults. Signs and symptoms found to be significant enough to include in the scoring include postexertional malaise, fatigue, brain fog, dizziness, gastrointestinal symptoms, palpitations, changes in sexual desire or capacity, loss of or change in smell or taste, thirst, chronic cough, chest pain, and abnormal movements.
Meanwhile, it's time to pay attention to the southern hemisphere, just as we do for influenza, since it could be a harbinger for what we'll see in a few months. We don't have the same level of monitoring as early in the pandemic, but I will keep my eye on Australia, where cases are rising in almost all states though still at a low level.
Lastly on the covid front, variant studies such as those in the UK continue to show we are living in an XBB variant world. I'm also keeping my eye on a new one, EM.1.
*Jack Aubrey is the fictional British naval officer appearing in 20 (+1 uncompleted) novels by Patrick O'Brian. I've read all the books and was pleased to see the first in the series recommended for summer reading by the Washington Post's (and fellow Silver Spring resident) Michael Dirda. The books take a little work, a lot of unfamiliar terminology and details to get through, so not quite the easy beach read. You may be more familiar with the movie Master and Commander which was actually a combination of events from 3 of his books.
Whatever you're up to this summer, try to make room for curling up with a few good reads.