community acquired pneumonia – Pediatric Infection Connection

“The horror! The horror!”*

Bud WiedermannMay 5, 2024May 5, 2024Leave a comment

Well, not really horror stories, but it was a slow week for epidemics that allowed me to finish two somewhat disturbing pieces of literature. First, the news.

I'm pleased to report nothing particularly new on the measles front, so I won't bother with the recitation of statistics and graphs. Based on the measles incubation period, it appears we are out of the woods from the Chicago clusters thanks to excellent public health interventions. The Florida school issue hasn't surfaced again though we are still lacking accurate descriptions of how it was managed - did un-immunized children isolate at home, were catch-up immunizations administered?

A Few Covid Updates

This past week the World Health Organization Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC if you're attracted to cumbersome acronyms) advised use of a monovalent JN.1 variant vaccine for the next iteration. Although the WHO TAG-CO-VAC doesn't make official recommendations for the US, none of these discussions occur in a vacuum and I expect the FDA VRBPAC to come to the same conclusion when they meet on the subject on May 16. The CDC/ACIP likely will rule on this in late June, in time for potential fall booster recommendations.

The most recent variant tracking in the US largely shows JN.1 and its offspring as predominant.

Here's the latest family tree in the US showing the.relationships of the currently circulating variants.

Also noteworthy is a change in hospital covid reporting. As of May 1, hospitals no longer are required to report covid hospitalizations. Although efforts are underway to go back to mandatory reporting, for now all hospital reporting is voluntary which will likely mean no reporting for many institutions. So, don't try to compare future covid hospitalization rates to prior data. It would be another apples and oranges comparison.

Lessons From Quality Improvement

This month's issue of Pediatrics contained some QI articles. They are worthwhile reading for the QI aspects, but I think many front-line pediatric healthcare providers might want to compare their own practices to the standards used in two of the studies concerning infectious diseases.

The first of the studies involved standards for management of well-appearing febrile infants ages 8 to 60 days in emergency departments. Parenthetically, I'm in awe of the authors for pulling off a multi-institutional research study in the midst of the pandemic. I barely had time to breath during some of those months.

The authors looked at multiple outcomes, and I won't go into the actual QI processes themselves. Here are the primary measures they sought to improve (remember these are all well-appearing infants):

90% of infants 29–60 d with normal inflammatory markers (and either a negative UA or a positive UA) DO NOT have CSF obtained
90% of infants 29–60 d with normal inflammatory markers and negative UA discharged from the ED
90% of infants 29–60 d with normal inflammatory markers and negative UA DO NOT receive antibiotics
90% of infants 8–60 d with negative cultures have appropriate discharge from the hospital within 36 h from the time blood cultures were received by the laboratory

How does your local ED or practice compare?

The second article also was hospital-focused and carried out during pandemic peaks. It dealt with minimizing unnecessary antibiotic use in common pediatric infections for children above 60 days of age. Again, many outcomes were examined, but think about these in your own practice:

Antibiotic duration for community-acquired pneumonia < 10 days
Antibiotic duration for UTI < 10 days
Antibiotic duration for skin and soft tissue infections < 5 days

The above durations for CAP and UTI probably are too long. It would be difficult to justify therapy beyond 7 days for these entities assuming good clinical response, and courses as short as 5 days have been suggested.

There's a lot more to these studies that I haven't mentioned. Please look at them if you manage these types of patients in your practice.

Of Cows and Cats

Bird flu, primarily influenza A H5N1, continues to surprise us. Let me state up front, however, there is no reason to be overly concerned about consumption of pasteurized dairy products or getting rid of your pet cat. People who ingest unpasteurized dairy or have close contact with cows or chickens (including those backyard coops) need to be cautious.

The count of bird flu in wild mammals continues to expand:

Genetic testing of dairy cow milk samples and of 2 cats who died at the dairy farm strongly suggests transmission of influenza A H5N1 from cows to cats. The cats had ingested unpasteurized milk at the farm. The cows were only mildly ill, but the cats had severe neurologic symptoms due to the virus. This report concerns only a few animals but at the least suggests that humans could be at risk for infection from unpasteurized dairy products.

We still have only one known human infection related to dairy cows in the US, but now we have more details about that case. As reported earlier, this dairy farm worker had mild symptoms consisting of pain and redness of the right eye. Especially given the perhaps mild and atypical presentation of influenza in this instance, more testing of asymptomatic dairy workers and other high risk individuals is needed.

I had mentioned in previous posts I'm trying to monitor USDA updates on this situation, but so far most have just clogged my inbox with irrelevant notices. I did receive one relevant alert that at least told me someone is watching out for us. Due to concerns about bird flu in the Chiba prefecture in Japan, imports of live birds as well as bird products and byproducts are prohibited. In case you are thinking about bringing back some bird souvenirs from Chiba, please be aware:

"Processed avian products and byproducts, including eggs and egg products, for personal use originating from or transiting a restricted prefecture and entering in passenger baggage must:

have a thoroughly cooked appearance; or
be shelf-stable as a result of APHIS-approved packaging and cooking (i.e., packaged in a hermetically sealed container and cooked by a commercial method after such packing to produce an article that is shelf stable without refrigeration); or
be accompanied by an APHIS import permit and/or government certification confirming that the products or byproducts were treated in accordance with APHIS requirements.

Unprocessed avian products and byproducts for personal use or in passenger baggage originating from or transiting a restricted prefecture will not be permitted to enter the United States. This includes hunter harvested, non-fully finished avian trophies and meat."

Reliable information on bird flu is increasing. It seems very likely that pasteurization effectively inactivates live H5N1 from dairy products and that these influenza strains remain susceptible to commonly available antiviral agents used for influenza. But, I still have questions:

What is the range of symptoms of avian flu infection in a wide range of animals, including humans?
How common is asymptomatic infection in various species?
What is the specificity and sensitivity of commonly-used influenza detection methods for influenza A H5N1?

For now, even though we are beyond our winter flu season, anyone with flu-like illness should be tested for influenza and also asked about exposure risks involving domestic or wild animals or ingestion of unpasteurized dairy products. Look to the CDC website for guidance.

My Disturbing Week

My wife abandoned reading Ian McEwan's latest novel, Lessons, due to its unsettling content in its early pages. Nonetheless, I decided to slog through this nearly 500-page tome and found I couldn't put it down. It was truly disturbing, including depictions of abuse of the young male protagonist that were hard to read. Ultimately, though, I found the novel very thought-provoking in spite of the fact that the protagonist wasn't very likable and seemed to respond passively to much of his life events. These events were shaped by a series of historical occurrences that also were meaningful to me: World War II (before my time, but still significant) the Cuban missile crisis in the 1960s, the fall of the Berlin wall, the September 11 attack, and more recently the January 6 attack, among others.

About a week ago I happened to watch Apocalypse Now Redux, the longer version of the 1979 movie about the Vietnam War which itself was a take on Joseph Conrad's Heart of Darkness. The longer movie version added more uncomfortable scenes to the already unsettling original. As a boy I had read at least 3 of Conrad's novels plus maybe a few short stories, but never Heart of Darkness. It's really a novella, just under 150 pages, and I felt compelled to read it this week. I loved it, as I do most of Contrad's works. More than that, I was astounded at how deftly the novella was transplanted from the late 19th century into late 1960s Vietnam. How did it not win the academy award for best adapted screenplay? (That was Kramer vs. Kramer.) I found myself waiting to see if the 19th century Kurtz would have the same *final utterance as in the movie version. You'll need to read the book to find out!

My Respite Week

Given the slow times in infectious diseases (now I've jinxed myself) and a busy week of other activities in front of me, I'm planning to skip a Sunday post for Mother's Day. Barring any major events, I'll see you next on May 19.

Winter Distractions

Bud WiedermannJanuary 7, 2024January 7, 2024Leave a comment

My soon-to-be daughter-in-law recently gave me a bird feeder - not just any bird feeder, but a smart one that has a camera connected to my wifi that takes photos and videos of any birds that show up. I had my first visitors this morning, a few days after I stocked it with birdseed.

In the meantime, winter is here.

WRIS

A lot going on with our Winter Respiratory Infection Season, including some new items.

CDC issued new (or actually old) guidance for use of the long-acting monoclonal antibody nirsevimab for preventing RSV infection in young infants. The change was prompted by the announcement of greater availability of nirsevimab because the manufacturer released an additional 230,000 doses this month. Previously the guidance had indicated that the product should be prioritized for just a subset of infants at higher risk, but now recommendations are to go back to the original plan to administer to all infants less than 8 months of age as well as to infants 8-19 months of age with high risk conditions:

Children who have chronic lung disease of prematurity who required medical support (chronic corticosteroid therapy, diuretic therapy, or supplemental oxygen) any time during the 6-month period before the start of the second RSV season
Children with severe immunocompromise
Children with cystic fibrosis who have severe disease
American Indian and Alaska Native children

If supply is still limited in your particular area, then prioritization should be used as before. Still a bit vague but very important are all the nuances for ordering, administering, and being reimbursed for the product.

Along that same line, RSV may have peaked nationally.

Even with some good news about RSV slowing down, there's still plenty to go around. Also, influenza continues to drive a lot of healthcare usage for all ages around the country. Here is the percentage of emergency department visits due to the various respiratory infections:

Be aware that this site allows you to look just at your local jurisdiction - here is Maryland:

Covid

This week covid deserves a separate heading with a few new twists. Wastewater tracking once again has accurately predicted a surge in infections.

The JN.1 variant has increased rapidly and is projected to be the predominant covid strain in the US, but without any indication (yet) that it has increased virulence.

This might be a good time to review a bit about variants and also some recent covid findings. Variant nomenclature is confusing to me, I can only imagine how the general public sees this. Here is an evolutionary tree from the same CDC weblink as above.

The nomenclature is from the Pango system, but most people are more familiar with the WHO classification: the delta variant (remember those horrible days?) is B.1.617.2 near the left of the diagram. Omicron is represented in both BA.1 and BA.2. Now here's the important part when we consider new variants, immune-escape, and vaccines: JN.1 has developed on the BA.2 side, just like XBB but on a different branch of the tree. Remember that our current vaccines are based on XBB. As I've mentioned previously, XBB vaccine antibody seems to neutralize JN.1 pretty well in the test tube, but all vaccine (and natural infection) immunity declines significantly within a few months after vaccination or immunization. I would still expect the current vaccine to be pretty good for protecting against severe disease with JN.1 infection.

Although near and dear to my heart, I don't usually talk about old folks in this blog. However, a study of old folks in the Netherlands lends support to the idea that current vaccines are effective against new variants. Without going into details, you can see this study has very recent data and show excellent effectiveness for hospitalization and ICU admission for old folks. It's likely this benefit translates to the younger population that of course has lower rates of hospitalization overall.

Another recent study sheds some light on a question I've been wondering about for some time, namely how common asymptomatic covid infection might be in the omicron era. You might recall that one of the early surprises in 2020 was that asymptomatic infection was both common and very important for viral spread. That made the pandemic much more difficult to control. Now we have data from Hong Kong where rather unique epidemiologic circumstances prevailed. With a population of 7.5 million, Hong Kong officials had still had managed to prevent covid spread very effectively prior to the omicron era, with only about 0.5% of the population having been infected. That ended in early 2022, but it also offered researchers an opportunity to look at rates of asymptomatic infection during the omicron period because virtually none of the population had been infected previously. Using antibody testing, they estimated that 16% of the population was infected during the first 6 months of 2022 and that the percentage of asymptomatic cases was at least 42% (taken from those with reported SARS-CoV-2 infections) and possibly as high as 72% (looking at combined reported and unreported infections). Wow. That doesn't necessarily mean we would have those same rates of asymptomatic infection in the US where we've had a very different epidemiologic curve over the years, but I think it's likely we have a lot of asymptomatic covid surrounding us now.

Some good news about long covid, AKA PCC (post-COVID-19 condition) in children. This Canadian study looked at pediatric emergency department data and found that PCC was present in only 0.67% at the12-month follow-up periods in children testing positive for SARS-CoV-2. That's not the only good news part of this; the rate in a control group of children testing negative for covid was 0.16%, suggesting once again that other infections can trigger some of these long term symptoms. We have NIH-funded studies in the US ongoing now, with good control groups, that should go a long way in giving us guidance for managing PCC as well as other long-term conditions triggered by infections.

The Tipping Point

FDA officials, including Peter Marks who is the director of CBER, recently published a viewpoint article about a vaccination tipping point, i.e. the fact that vaccine hesitancy issues have resulted in a severe decrease in immunization coverage, opening us up to major outbreaks soon. I mention this both because it perfectly supports my views expressed in recent weeks but also it gives me a chance to give credit where credit is due. The term "tipping point," as applied here, often has been credited to Malcolm Gladwell. However, his popularization of the term in a sociologic context earlier this century should go to Morton Grodzins who first adapted this for use in explaining racial integration of neighborhoods in the middle of the 20th century. I'm hoping Gladwell credited him.

In Case You Missed These

Two other articles caught my eye this past week. First is a quality improvement article about shortening treatment duration for children with community acquired pneumonia and skin and soft tissue infections. If you're one of those practitioners who still treats these for 10 days (because we have 10 fingers), check it out.

Secondly, I was attracted to a report about variation in rates of how primary pediatric providers use pediatric subspecialty consultations. Although not the main focus of the report, I was most drawn to the mention that the top 2 conditions for using a pediatric infectious diseases specialist were positive tuberculin skin test and inactive tuberculosis. This jives with my personal experience and certainly points to opportunities to lessen use of subspecialty health care. Multiple resources exist for managing latent tuberculosis infection, including the AAP's Red Book, the CDC, and UCSF's Pediatric TB Resource Page.

For the Birds

My first video stars at the bird feeder were a white-breasted nuthatch, maybe a tufted titmouse (looks a lot like the nuthatch, I couldn't figure it out), and a house finch. When I received the bird feeder, I immediately wondered how best to avoid attracting squirrels and other rodents. I did a bit of web searching and then journeyed to my local bird authorities at the Woodend Nature Sanctuary who of course turned out to be the most helpful. I armed my feeder with capsaicin-treated safflower seeds, not a favorite of squirrels and the like, plus birds can't taste the hot pepper. So far the birds seem to like it.

As for me, it appears I've fallen down another rabbit hole, similar to my butterfly fascination. My wanderings have now included a look at how climate change is affecting our bird populations, as projected by the Audubon Society (apologies for using his name, now controversial, but the Society hasn't yet changed it) in their field guide.

Here is how things will change for the white-breasted nuthatch's winter range with a 1.5 C increase in temperature.

For the tufted titmouse

and the house finch

With more severe temperature increases, the ranges are altered more dramatically. I still hope for some action that will reverse these trends.

Welcome Breathing Room

Bud WiedermannJanuary 23, 2022January 26, 2022Leave a comment

All systems point to the downswing of the omicron wave which is good news for everyone. Risking being labelled a party-pooper, I hasten to add that we cannot let our guard down. Note that we have had 2 variants cause global upheaval in just the second half of 2021 plus still vast portions of the world's population lacking vaccination. It is a question of when, not if, the next variant of concern appears. (I'll rejoice if I'm proven wrong.) We need to accelerate all preventive measures including delivery of vaccines and boosters worldwide.

Continued Evidence That Vaccines Work

Last week saw publication of 4 new studies all showing the benefit of COVID-19 vaccination in protection against serious illness.

A study released by CDC last Wednesday I think got a bit twisted by some press reports into appearing to advocate that being unvaccinated was a good plan. The study looked at surveillance data from California and New York. A summary statement, "By early October, persons who survived a previous infection had lower case rates than persons who were vaccinated alone," was the source of confusion. The confusion can be clarified by a nice graph that unfortunately only appeared as an online supplement to the report, meaning that readers would have had to read through some pretty dense tables of numbers or take an extra mouse click to get a good appreciation of the situation. Here is one of the supplementary figures from New York. Look at the distance between the solid blue line (unvaccinated) and the 3 lines at the bottom. Yes, it is true that vaccinated individuals with no prior infection history had slightly higher hazard rates for lab-confirmed infection, but not that much more compared to the rates of vaccinated or unvaccinated people who had prior infection. Being vaccinated was far better than being unvaccinated regardless of prior infection history. Also, these data are mostly before the omicron surge when everything changed, and it did not look at booster status.

The second study did evaluate booster status and was highly encouraging. The authors, from the CDC, used the familiar test-negative study design and were able to judge the association between 3 doses of either the Pfizer or Moderna vaccine with protection from symptomatic COVID-19 disease against both delta and omicron variants. This study design only permits calculation of odds ratios rather than true relative risks but can be used as an approximation. Comparing 3 doses of an mRNA vaccine to being unvaccinated, odds ratios were 0.33 (95% CI 0.31-0.35) for omicron and 0.065 ((0.059-0.071) for delta, i.e. significantly in favor of vaccination. Similarly, a comparison of 3 versus 2 doses of vaccine showed odds ratios of 0.34 (0.32-0.36) and 0.16 (0.14-0.17) for omicron and delta, respectively. We'll need to see a follow-up to these data since the study extended only through January 1, 2022.
Another study from CDC compared disease incidence and death rates among unvaccinated and fully vaccinated adults, with and without boosters in 25 sites in the US. Significant benefits were demonstrated for the vaccinated and boosted groups, especially for ages 50 years and above.
Also worth noting is a study focused on benefit of third doses in preventing emergency and urgent care visits and hospitalizations in 10 states, covering the August 2021 through some of January 2022. As you might guess by now, the data lend further evidence of the benefit of vaccinations and boosters.

Ten Fingers Ten Days

Only those who have suffered through a clinical rotation with me on the infectious diseases service at Children's National Hospital will recognize the heading above. It is law #5 in Bud's Laws, a list of 10 aphorisms that I've been tweaking the last few decades. It refers to the fact that most antibiotic treatment durations we use are based on little to no evidence. I've maintained that if we were an animal species with 12 fingers we'd be treating everything for 12 days instead of 10.

Enter a new study, the SCOUT-CAP trial. (I won't even mention the origin of such an acronym, it's too long and too forced into forming the acronym itself. Other acronyms in the study are RADAR and DOOR; very cute.) This was a randomized double-blind placebo-controlled trial of 5 versus 10 days of oral antibiotic therapy for outpatient community acquired pneumonia taking place in 8 US cities. It included 380 children 6-71 months of age diagnosed with CAP and initially prescribed one of 3 commonly used regimens (amoxicillin, amoxicillin/clavulanate, or cefdinir) to treat CAP. Children were continued on their original therapy, then randomized to continue that treatment or switch to placebo on days 6-10. (Note that over 90% of the children received amoxicillin originally.) Fewer than 10% of children overall had an inadequate clinical response regardless of treatment assignment, probably indicative of the fact that most children had viral infections and never needed an antibiotic in the first place. However, the 5-day course individuals had better scores for resolution of symptoms and antibiotic-associated side effects, as well as a lower incidence of antibiotic-resistance genes detected in throat swabs obtained in a subset of the participants.

You might have correctly concluded that if the main thing about the study that I'm complaining about is use of acronyms, the study itself is pretty good. It's very difficult to design a study of mild CAP that both applies to real-world practice and has enough safeguards to prevent bias from study design, and this study achieved those goals.

I'm not suggesting we all amputate 5 of our fingers, but please think about shortening courses of antibiotics for outpatient pneumonia in relatively healthy children.

[Note this section was updated January 26 to clarify that this was basically a study of 5 versus 10 days of amoxicillin therapy, too few children received amox/clav or cefdinir to comment.]

Tag: community acquired pneumonia