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At this time of year many of us turn our thoughts to ancient times, whether to the second century BCE (for the Maccabees and Hanukkah), the first century CE (Jesus and Christmas), or other wintertime traditions even dating back to 10,000 BCE and celebrations related to the winter solstice. A recent article turned my thoughts to a little earlier time in antiquity, around 7000 BCE. But first ....

WHO Cholera Update

New reporting from WHO is a bit depressing, given that cholera is controllable with good sanitation, plus we have effective vaccines and treatments available. Worldwide cases this year, as of November 24, increased 37% compared to last year. So far, we are up to 733,956 cholera cases and 5162 deaths from 33 countries across five WHO regions. WHO cites multiple factors for the increase, including vaccine shortages, climate change, conflict, mass displacement, and natural disasters including floods.

Avoid Bats**t

Among other things to avoid, bat guano is not a healthy choice. Researchers at the University of Rochester reported 2 fatalities from histoplasmosis traced to bat guano used as fertilizer for marijuana plants. Both were adults with underlying medical conditions. Infection with Histoplasma capsulatum usually is asymptomatic but can become symptomatic and severe with massive exposure or in persons with high risk factors such as immunosuppression.

Avian Flu

Though not wanting to contribute to over-dramatization of our ongoing saga of influenza A H5N1 in poultry and cows, the count of human infections is still increasing slowly, now at 64 cases nationally. Most importantly, we still have no evidence of human-to-human transmission, and it remains mostly a relatively mild infection in humans. Probably the biggest impact we all see is in the price of eggs.

This past week we saw confirmation of severe disease in a human. It occurred in an adult with significant underlying medical conditions who had exposure to dead and ill birds in a backyard flock. Genomic sequencing of the person's flu strain suggested its likely origin as being from avian as opposed to bovine origin. Front line health care providers should take this as a reminder to inquire about exposure to birds, both wild and domestic, and to cows as a routine part of evaluation of flu-like illness.

Please Consider Antiviral Therapy for Influenza

This past week I consulted on a child hospitalized with pneumonia who had a mild respiratory illness testing positive for influenza about 10 days previously. The child hadn't received flu vaccine this season, and the urgent care physician who diagnosed flu did not prescribe treatment for influenza. I don't know if oseltamivir treatment would have prevented the hospitalization, which could have been a separate illness, but the case did remind me that many providers are not using the tools at our disposal to help prevent adverse outcomes from flu.

A recent multicenter study revealed that about half of children hospitalized for influenza did not receive antiviral therapy. Various factors were associated with receipt of therapy.

As a reminder, we have a total of 4 drugs approved for treatment of influenza: oseltamivir (Tamiflu) and baloxavir (Xofluza) are oral agents. Other options are intravenous peramivir and inhaled zanamivir. While anti-influenza treatment works better in the first 2 days of illness, there is still benefit from treatment started later. Also, there isn't much point in testing for influenza if you're not going to treat it!

WRIS

We are well into winter respiratory infection season now, largely driven by RSV and influenza. I'd encourage everyone to look into the status for your own location at the CDC website.

Ancient Times: The Origins of Syphilis

We've seen a lot of controversy (and shouting) the past few years regarding the origins of covid. A recent archeologic study on the origins of syphilis and other treponemal diseases caught my eye. Although I'm not aware of any shouting matches around this origin controversy, it's noteworthy that the answer still is a bit up in the air. The study used genome analysis of multiple specimens and provides convincing evidence that treponemal diseases originated in the Americas. Their findings, along with many others, suggests that we can blame Columbus for bringing syphilis to Europe but not vice versa as some have postulated.

I should remind everyone that there are 3 forms of human disease caused by Treponema pallidum: T. pallidum pallidum (syphilis), T. pallidum pertenue (yaws), and T pallidum endemicum (bejel). (Pinta, the mildest human treponematosis, is caused by T. carateum.)

Regardless of whether you celebrate this holiday season based on traditions from the time of winter solstice recognition and the origins of treponemal disease or the more recent and more common religious and secular traditions (remember Festivus?), I wish everyone a wonderful time the next few weeks.

Courtesy of https://commons.wikimedia.org/wiki/File:Festivus_Pole.jpg.

I was very underwhelmed by Oxford University's recently announced Word of the Year. Listening to last week's FDA VRBPAC discussion of RSV vaccines, another word kept cropping up time after time. More on that later.

Covid Updates

I had mixed feelings when I learned that the Netherlands had started a Long COVID Kids Choir, apparently also active in the UK and the US. On the one hand, it's great that these children have on outlet to express themselves, but on the other hand it reminds me how little we know about this condition.

On a more uniformly upbeat note, new data are available for effectiveness of the Pfizer XBB vaccine in children 5 - 17 years of age. This was a retrospective study from Kaiser Permanente Southern California looking at acute respiratory infection visits from October, 2023, through April, 2024. Because of the study design (standard test-negative case-control study) we only have odds ratios to describe results; number needed to vaccinate can be estimated from odds ratios with fudge factors, but I'm reluctant to go there. Here's the summary:

Basically, the vaccine was very effective in preventing hospital admission and ED/urgent care visits in this age group.

Temporal Thermometers Not the Greatest

Temperature measurement using temporal thermometers is pretty much a tradeoff - convenience versus accuracy. A new study from 5 EDs in a single system (apparently Mass General but hard to tell from the article) looked at around 1400 children who had both temporal and oral or rectal temperatures measured at the same time (within 30 minutes). The findings are summarized here; note mean discordance of about 1.5 F. Researchers found that age < 12 years was was associated with discordance.

The authors found that self-reported race was not a risk factor, important because skin color could plausibly affect temporal measurements. As an interesting aside, Black children were more likely to have temporal temps only, even correcting for severity of presenting complaint.

Avian Flu

I'm keeping a wary eye on new progress, mostly because I'm worried that not enough resources are being devoted to monitoring the situation. One new report provides helpful information. Two dairy farms voluntarily allowed investigators to look at prevalence and spread of influenza A H5N1 in their settings. Here's the "graphical abstract::

The authors mention the rarity of these types of studies possibly due to farm owners' worries about harm to their businesses from publicity about avian flu spread in their dairies.

CDC provided genetic sequencing information about the virus infecting the child in California who apparently has no known avian flu exposure risks. Analysis suggested that the strain was very similar to those previously seen in dairy and poultry farms as well as in humans, but they were unable to perform complete sequencing that could have allowed further tracking of the source of this child's infection. I guess due to privacy concerns, we have very little clinical information about this case. I'm even wondering how the child's strain came to be tested for H5N1 in the first place since not every influenza A detection undergoes further testing.

Regardless of uncertainties, these most recent reports do not suggest we need to heighten concern for human to human transmission of A H5N1.

DRC Mystery Disease

Shortly after my post last Sunday, WHO released a new update with a few more details but still no big findings. I can't even find their case definition anywhere. The initial statements that respiratory symptoms predominated would seem to make malaria, where positive tests have been seen in preliminary testing, a less likely explanation. Malnutrition seems to be a significant risk factor.

WRIS

Winter Respiratory Infection Season continues to mount with moderate level activity in the US driven primarily by RSV.

Epidemic trending (modeling data for predictions, from the same link as above) shows continued growth for covid ...

.... and especially for influenza.

It's still not too late for flu vaccine. Expect a surge soon if not already started in your area.

RSV Vaccine Conundrum

I was glued to my screen for much of last Thursday's FDA VRBPAC meeting, with the majority of the session devoted to discussion of pediatric RSV vaccine progress, or lack thereof. As I've mentioned in previous posts, RSV vaccine development for children was set back by a tragic trial in the 1960s where vaccine-associated enhanced respiratory disease (VAERD) resulted in 2 deaths of children who received vaccine and then subsequently were infected with wild-type RSV the following season. Through many scientific advances over the years, researchers determined that the cause of this enhanced disease was immunologic in nature, related to the vaccine causing recipients to develop a strong cellular immune response involving a specific class of T cells (Th2). This finding even influenced development of the mRNA covid vaccines which deliberately avoided this and ensured a Th1-predominant response and very safe vaccines.

Unfortunately, recent experiences in trials for Moderna RSV vaccines suggested that VAERD might be occurring in children under 2 years of age. Moderna was developing 2 mRNA RSV vaccines, 1 for RSV alone and another that also incorporated a human metapneumovirus vaccine. They were enrolling children in a phase 1 study this summer when the concerning signal arose. I am including slides from the FDA presentation. Here's the study overview and timeline of events this summer, from slide numbers 11 and 12.

I included the above to demonstrate that the safety constraints incorporated into the study worked exactly as intended. Enrollment was paused pending evaluation of the events, which is still ongoing. The imbalance between vaccine and placebo recipients is highlighted below:

Note the small number of children in the study, appropriate and typical for phase 1 trials. However, that makes analysis more difficult. I'll cut to the conundrum chase. Preliminary immunologic studies from patients in the Moderna trials suggest that the vaccine, as planned, produced Th1-predominant responses, and that the mechanism of the possible VAERD events is not due to Th2-primed cells. Furthermore, other immunologic data don't provide another plausible information for why this happened.

Of course, with so few trial subjects, it's possible that this imbalance of severe disease could be due to chance alone. Regardless, Moderna officials announced that they would be abandoning the mRNA RSV vaccine development but will continue to follow all the children already enrolled in their studies and perform further immunologic and other testing.

So, where does that leave us with RSV prevention? This took up much of the VRBPAC's discussion time. It's important to understand that the Moderna RSV vaccines were part of a larger group of pediatric RSV vaccines in various stages of development, 26 in all. Fifteen of these are live attenuated vaccines, and it should be noted that live-attenuated vaccines have never been shown to result in VAERD, with extensive validation for why that hasn't occurred. (I might add that your dog's kennel cough vaccine might contain one of these. Although Bordetella bronchiseptica is the most recognized cause of kennel cough, canine adenovirus - 2 and parainfluenza virus 5 are other common causes of kennel cough and also have been included in some intranasal dog vaccines for decades. Presumably most of us have been exposed to our dogs' live attenuated vaccine PIV5 strain many times, yet no human VAERD involving parainfluenza virus has ever been described.)

It is likely that future pediatric RSV trials will need to be judged on an even more individual basis, perhaps with separate constructs governing the various platform differences (live attenuated, viral-vectored, mRNA if anyone moves forward with this, and subunit protein) as well as mode of delivery - mucosal (intranasal) versus systemic by injection. In the meantime, we know that maternal immunization is highly effective, as is the infant monoclonal antibody nirsevimab. In that light, we also need development of newer monoclonal antibody products in case nirsevimab resistance appears, as well as better maternal vaccines that won't be so limited in timing of administration during pregnancy. Work is ongoing in all of these venues.

Conundrum

Of course I had to look into the origins of the word, but it turns out there is a lot of disagreement about this. I was most delighted to see the word explained as a "burlesque imitation of scholastic Latin." I was unaware that it was the title of a Jethro Tull instrumental song (I'm not much of a Tull fan) and an episode of Star Trek: The Next Generation (I am a fan, but don't remember the episode).

Have a great week, and don't forgot to offer flu and covid vaccines to your patients and families.

The Democratic Republic of Congo has been back in the news, this time not for mpox but for a mystery illness in an isolated, rural region of the country. Varying numbers of fatalities have been noted, but solid facts are sorely lacking. I am reminded of how early outbreak news percolates and changes; odds are low but not zero that this is a serious, new pathogen. Meanwhile, we can discuss several new publications that are on more solid scientific footing.

Vaccine Effectiveness Updates

Two manuscripts accepted for publication provided new information on VE measurements, one concerning influenza and the other looking at covid vaccines in young children.

CDC, along with other investigators, published an analysis of influenza VE for the 2023-24 flu season. For that year, the vaccine strains were well-matched for what eventually circulated in the US. The most common strain circulating was A H5N1pdm2009. Looking just at the pediatric population, VE in preventing hospitalizations and urgent care/ED visits was very good in all age groups as shown below: 58% for both outcomes overall, though with a wider confidence interval for hospitalizations since these were less common events.

The covid vaccine article is quite complex, involving investigators at multiple sites and listing 35 identified authors! Sadly it doesn't have any nice tables/figures that allow a short summary. I see 2 categories of take-home messages from the data: 1) as always, VE depends on which outcome you're looking at; 2) covid vaccines aren't that effective at preventing infection, but do help significantly in preventing complications of infection.

This multi-center study is actually a grouping of 3 cohorts (total 614 subjects) of children who had longitudinally-collected data including weekly sampling during the period of omicron variant circulation, 9/19/22 - 4/30/23. Variants were verified by genetic sequencing of about half the strains. Antibody studies and history questionnaires at study entry were utilized to determine evidence of prior infection. Here are the numbers from the study:

  1. Children with prior infection had less chance of both infection and symptomatic infection than did those without prior infection: Hazard Ratio [HR]: 0.28 [95%CI: 0.16-0.49] and HR: 0.21 [95%CI: 0.08-0.54. This was true regardless of timing of prior infection.
  2. Children with prior infection AND vaccination also had lower hazard ratios: HR: 0.31 [95%CI: 0.13-0.77], compared to those who were unvaccinated with no prior infection.
  3. The one slightly unique finding in this study is as follows: "There was no difference in risk of infection or symptomatic COVID-19 by vaccination status alone, regardless of timing of vaccination or manufacturer type. However, naïve participants vaccinated with Pfizer-BioNTech were more likely to be infected and experience symptomatic COVID-19 compared to naïve and unvaccinated participants (HR: 2.59 [95%CI: 1.27-5.28]), whereas participants with evidence of prior infection and who were vaccinated with Pfizer-BioNTech were less likely to be infected (HR: 0.22 [95%CI: 0.05-0.95])." In other words, vaccination didn't do very well at preventing infection.

This study is very complex but also very rigorous; I can't do it justice in a small summary. The major limitation is the relatively low sample size, meaning that the investigators couldn't do much in the way of subgroup analysis to try to look at other variables. Relatively few children received the bivalent Pfizer vaccine, so it's very hard to interpret specific differences between Pfizer and Moderna vaccines. Also, the small sample size precluded any assessment of complication risks following natural infection, one of the big advantages for being vaccinated.

Does Nirsevimab Prevent Other Infections Besides RSV?

According to another new study, the answer is "sort of." Investigators looked at around 3000 infants randomized 2:1 to receive either nirsevimab or placebo and then followed with respiratory swab PCR testing. The pictorial bottom line:

Not mentioned in the pictorial summary is that the cumulative incidence of rhinovirus/enterovirus coinfections was lower in the nirsevimab group, leading to my "sort of" conclusion.

The important bottom line of the study, however, is that no replacement infections appeared. Replacement infections refer to the concern that once an infectious agent is greatly reduced by preventive measures, another pathogen will take its place, lessening the impact of the preventive measure. This was a concern for Hib vaccine early on, but no other meningitic pathogens arose. Later, the same concern arose for pneumococcal vaccination. There is evidence that replacement pneumococcal serotypes started to become more common, but the overall rates of pneumococcal infections still declined significantly. This is why we're still trying to add other pneumococcal serotypes to newer conjugate vaccines.

Parvovirus and Myocarditis

Last week I mentioned the reports about increase in parvovirus infections likely spurred by non-pharmaceutical measures to prevent respiratory pathogen spread during the pandemic. A spinoff of this kind of surge can be a surge in complications of these pathogens. I was intrigued by this report from Italy about parvoviral myocarditis, which is a slightly controversial topic. Etiology of viral myocarditis is difficult to determine without myocardial biopsy, and parvovirus myocarditis is particularly suspect because of older reports of parvoviral detection in cardiac tissue from individuals who never had concern for myocarditis. So, for an individual patient, it's hard to be certain of a parvoviral etiology for myocarditis even with a positive tissue biopsy. This post-pandemic surge may help clarify the situation.

Europe in general seemed to have an earlier surge in parvovirus infection than we did in the US, possibly because pandemic restrictions were lessened earlier there. Here is a breakdown of the Italian report by age and timing.

And a breakdown of how the diagnosis was made. Only 2 were with myocardial biopsy; blood PCR can persist positive for a long time after parvoviral infection. IgM serology always is suspect due to nonspecific factors. A matched control group without myocarditis to see rates of parvovirus IgM and blood PCR positivity would have been helpful.

Of course I'm hoping we don't see a surge of myocarditis cases soon. If cases do spike, it will be particularly tough to figure out if it happens during a covid surge.

Mycoplasma Complications Too?

Along similar lines, a study from Texas suggests that the Mycoplasma pneumoniae surge might be associated with a greater risk of complications. This is a retrospective review from a single institution documenting an increase in M. pneumoniae infections seen below the shaded section.

It's important to recognize, as the authors do, that this is a cohort skewed towards inpatients who had multiplex PCR testing. Also, mycoplasma PCR can persist positive for many weeks after infection (as do live organisms), so a positive PCR doesn't conclusively mean that the current illness is caused by mycoplasma. What was important and of some concern in the report is that 13 of the 41 children hospitalized with respiratory symptoms required ICU care. They also described 16 children with RIME (Reactive Infectious Mucocutaneous Eruption) with one of those children requiring ICU admission.

Avian Flu Updates

The news media (sometimes breathlessly) relayed new findings that a single mutation in influenza A H5N1 strains could increase adherence to human respiratory epithelium, increasing chances for greater infection rates in humans. I haven't yet bought into this panic.

Keep in mind that single mutations don't necessarily occur in isolation; often multiple mutations occur, some increasing virulence while others resulting in lower virulence. This in vitro study is an important contribution to our understanding of how avian flu might evolve and most importantly supports the need for close tracking of this agent in all animals, including humans.

Along those lines, I was please to hear that the US Department of Agriculture will implement mandatory milk testing nationwide for A H5N1. Previously this has been mostly a voluntary effort in the US. We still need much more monitoring for this agent in order to prepare for potential increase in human cases. Let's hope funding will be available to support these efforts.

WRIS

The winter respiratory infection season has begun, at least for RSV. We are now officially at moderate activity nationwide.

Influenza is increasing slowly with A H3N2 the most common subtype. COVID-19 projections are increasing, though not yet a big bump in clinical illness.

WHO to Help in the DRC

I figure I've been watching various feeds for outbreak alerts for about 30 years, starting with the ProMED service that still sends me at least a daily update. So, I've had early looks at these events, but also a slew of false alarms of new diseases that turned out to be mini-outbreaks of previously well-described illnesses. The latter are far more common than newly emerging infectious agents. So, I'm both watching closely but not overly concerned about the cluster of respiratory illnesses with significant mortality being reported from Kwango province (outlined in red) in rural southwestern DRC, bordering Angola.

Early reports suggest a predilection for children. The rural location with lack of medical facilities hinders any investigation. Also, this type of region, with close proximity of humans to many animal species, provides the potential for infectious agents to jump to other animal hosts. It appears the region now has appropriate support from WHO, and I would expect to hear more definitive information within the next several days, maybe in time for an update in my next post.

I guess the rural location is also a silver lining, with less risk for worldwide spread if this is in fact a new disease. I'll go out on a limb using past unknown outbreak experience and predict this won't be a new pathogen. Here's hoping.

Thanksgiving week has arrived, which for me means making checklists and time schedules and then revising them several times up until Thursday, at which point nothing happens according to schedule and I just go with the flow. It's also a time I remember the infamous Wiedermann Thanksgiving Massacree of 199? (I can't remember the exact year), with apologies to Arlo Guthrie.

Understandably in the past few years, this blog has drifted to the latest public health and epidemiologic trends, but I'm comforted by the fact that respiratory infections remain relatively calm and that this past week's publications allow me to focus more on recent original studies of interest to pediatric healthcare providers and the general public.

Macrolide-resistant Mycoplasma pneumoniae

I'm getting pretty tired of hearing about our resurgence of "walking pneumonia," but this article caught my eye. It's a report from North Dakota, and my interest wasn't in the fact that the investigators found evidence of macrolide resistance; that's nothing new. The bigger question is whether the resistance has major clinical significance. I've stated previously that, because Mycoplasma lower respiratory infection is largely a self-limited disease, it's difficult to know whether antibiotic treatment helps, and if it does, whether the amount of benefit is worth treating with antibiotics. The vast majority of "walking pneumonia" cases in children don't need any nasal swab or radiographic testing, nor any treatment.

The study was small, just based on 10 children of which 8 had macrolide resistance genes detected in their nasal swab assays. Six of them were said to have failed azithromycin treatment, though the authors didn't define treatment failure. Six of the patients who had fever and received doxycycline or levofloxacin became afebrile within 24-48 hours. Needless to say, this doesn't translate to great evidence that macrolide resistance is clinically important; it does point to the fact that we need randomized controlled trials to answer this question. Unfortunately, studies need funding, and this condition isn't likely to be profitable enough for funding from a pharmaceutical company. My only takeaway from the study is that further evaluation and treatment should be considered in children with possible pneumonia in whom symptoms worsen or fever persists more than a few days. Unfortunately, M. pneumoniae susceptibility testing isn't routinely available. For mild community-acquired pneumonia in children, amoxicillin is the treatment of choice, with azithromycin as a second-line agent. Switching to doxycycline or levofloxacin should be reserved for macrolide treatment failure, however that is defined.

Certainly we are having a banner year for mycooplasma respiratory infections, likely a combination of the normal mycoplasma surges we see every few years and lack of exposure during pandemic years. Which brings us to ...

Immune Debt

I really liked this new article that looked at the concept of a dose response effect in immune debt, i.e. that the magnitude of illness we see in rebounds of respiratory infections post-pandemic should be proportional to how much less frequent these infections were during the pandemic. The statistical methods in the study are somewhat beyond my expertise, but I mostly think the authors proved their point that lifting of non-pharmaceutical interventions (NPI) around the world seemed to be a point of increase for various respiratory infections. Here's a sample of the findings.

If this is all true, presumably we'll be back to the "old normal" of seasonal respiratory infections soon (barring another serious pandemic).

UTI Diagnosis

I must confesse my eyes rolled when I saw the title of this new study. Early in my career I was involved in UTI research. I've been very disappointed in analyses of UTI diagnosis in recent years because most of them seemed to ignore how variable accuracy of different UTI diagnostic laboratory methods are, even for something as basic as urinalysis. For example, it makes a big difference whether the number of white blood cells in urine is determined by machine (usually flow cytometry), manual counting by a lab technician with or without use of a hemocytometer, or just a urine leukocyte esterase dipstick. So, I was very pleasantly surprised that this group of investigators highlighted precisely those concerns. This was a study of around 4000 febrile children evaluated for UTI with urinalysis and culture, and the results showed that virtually all urinalysis components were poor at predicting a positive urine culture, defined as > 50,000 cfu/mL of a single pathogen in a catheterized urine specimen. The authors concluded that around 20% of children with febrile UTI could have normal urinalyses but also acknowledged how difficult it is to factor in asymptomatic bacteriuria (estimated rate 2%, but tough to assign an exact number) and specimen contamination. I don't think this study solves any of these issues, but it is an important contribution to our understanding of UTI diagnosis.

WRIS and Nowcasting

Last week CDC published a more detailed explanation of how the time-varying estimated reproductive number (Rt) can be used as an early warning for changes in respiratory pathogen transmission activity. This report is of interest mostly to true epidemiologic nerds, so of course I found it very enlightening. The authors did provide convincing evidence that this methodology has been working well recently.

We're not due for another respiratory illness outlook update from the CDC until mid-December, they only provide these every 2 months, but we remain mostly quiet. I suspect we'll see RSV and influenza hit pretty soon around the country. Again, you can check your own local illness and wastewater activity at the CDC' site.

Beware Studies Based on Administrative Data

This is one of my pet peeves: not the studies themselves, but how too much importance seems to be given to them in the lay press (bolstered by academic organizations seeking to get their names in the news). A new study shows how variable results can be from these databases, using the example of invasive bacterial infections in febrile infants. It's easy to imagine how any system based on diagnosis codes entered into various databases could lead to classification errors, but this report provides an excellent example to keep in mind. Any study using an administrative database should evaluate accuracy of diagnoses on a subset of patients to give some evaluation of the accuracy of their results (IMHO).

New 2025 Vaccination Schedules Published

The information isn't new, just based on prior FDA and ACIP deliberations mostly happening over the summer, but now we have the colorful schedules to use. The AAP has a quick summary of changes.

Happy Thanksgiving!

I have so much to be thankful for this year, and I hope not to repeat the Wiedermann Thanksgiving Massacree of maybe 30 years ago. I won't explain in full; it's too painful to spend anything like the 18 minutes, 34 seconds that Arlo Guthrie took to explain his Alice's Restaurant Thanksgiving Massacree of 1965. (Restaurant namesake Alice Brock died a few days ago.) The short version is that my attempt to create the perfect turkey gravy ended badly in an oil slick of glass shards in the kitchen. Why I'm still allowed to have any Thanksgiving responsibilities at all is a prime example of my wife's incredible powers of forgiveness.

We'll be hosting a relatively small gathering at our place this year. My duties are limited to turkey, gravy, and drinks. Starting today I'll have my checklists made out, separated into daily tasks. Thursday itself will have a well-choreographed timeline to include oven and stove use times in our smallish kitchen. As I said at the start, these scraps of paper will bear little resemblance to how the meal actually unfolds.

I won't go into detail about all the food-borne illnesses linked to turkey dinners, but please make good use of your food thermometer and follow guidelines.

And, speaking of Arlo, some of you might be interested in his live recording of "Amazing Grace" with Pete Seeger in 1993 (around the time of the Wiedermann Massacree!). It's 13 minutes of music and meanderings still meaningful in today's world.

U.S. Representative Tip O'Neill popularized this phrase in the early 1980s, but perhaps it lost its meaning in later years. Has that changed? Infectious diseases, on the other hand, are most certainly not local.

Infectious Diseases Abroad

Any ripple in communicable infectious diseases in one locale inevitably affects others in far-away locations. Last week saw a number of ripples.

(Not) Measles in American Samoa

Yes, I'm aware that American is a US territory, but it certainly qualifies as far-away.

In 2023, health authorities in American Samoa went on a wild goose chase based on non-recommended testing practices of a suspected case, resulting in a large expenditure of time and money with no benefit. I'm not faulting Samoan practitioners, they had to deal with a lack of available testing resources in the setting of an island rocked by a deadly measles outbreak a few years ago; that outbreak had been fueled in part by prominent anti-vaccination proponents. This recent episode should serve to remind us of proper use of measles diagnostic testing which relies most prominently on use only for individuals who fulfill proper case definitions.

The above report was in last week's MMWR which also contained a WHO measles update. Here's a comparison of 2000 and 2023 measles cases and deaths (note North America is not included in these numbers.)

Severe Avian Influenza in Canada?

Last week Canadian officials confirmed that a critically ill teenager is infected with influenza A H5N1. The source is still unknown, and no close contacts are known to be infected. It's been very tough to get details about the patient's illness, but after going through a transcript of a British Columbia health official's briefing on November 12, it seems that the previously healthy child presented with typical H5N1 symptoms of conjunctivitis, cough, and fever, but then several days later had deterioration. That sequence of events, a sort of biphasic illness, is classic for secondary bacterial complications of influenza. Influenza virus infection of any type can be complicated by secondary bacterial processes, including sepsis and toxic shock syndrome, usually several days after initial flu symptoms begin. Canadian authorities haven't provided any more details, but I wouldn't be surprised if this is what's going on. I'm hoping it was recognized quickly and his healthcare team can return this person to normal health.

Along these lines, NASEM just issued a new publication detailing research priorities for avian influenza A H5N1 readiness. Some of this is already happening, and I hope funding priorities will continue to support planning.

Mpox Update

Last week WHO updated the status of the mpox outbreaks across Africa, a mixture of good news and bad news. Priorities are delivering vaccine to those at risk and implementing newer PCR testing for mpox just approved by the AfricaCDC. Also this past week we learned of the first mpox clade 1 case in the US, occurring in a traveler returning from Africa.

Number Needed to Vaccinate for Covid in the UK

I've mentioned in previous posts that the UK recommends many fewer groups for covid vaccination than we do in the US, primarily because of cost considerations. Last week the UK's Joint Commission on Vaccination and Immunization gave us a bit of a closer look at how those decisions are made with some NNV calculations. NNV (along with its cousin Number Needed to Treat for medication) are a good way to explain "bang for the buck." NNV simply refers to the number of individuals needed to vaccinate to prevent one additional case of the infection, compared to no vaccination. It depends on many variables including the rate of the disease and the number of susceptible individuals in the community and the vaccine effectiveness. Also, NNVs vary with the outcome of interest, such as infection versus hospitalization versus death. It's increasingly harder to calculate NNVs for covid vaccine because of asymptomatic infections and less widespread testing being performed.

The JCVI didn't give us NNVs for all age groups, but they did provide a close look at pregnant people and infants under 3 months of age, the latter group of course not eligible for vaccination and dependent on maternal immunity passed to them transplacentally. I had to dig into attachments to the reports, but here's the bottom line: NNV to prevent hospitalization of a pregnant person is "just under 2000" and "around 300,000" to prevent severe hospitalization. I couldn't find a definition of severe hospitalization but from the context it appears to be something more than overnight observation but less than ICU admission.

For infants < 3 months of age, NNVs (for maternal vaccination) were "under 500" for any hospitalization, "just over 13,000" for severe hospitalization, "almost 190,000" for ICU admission, and ranged from 380,000 to 1.5 million for mortality, the latter extremely hard to calculate due to rarity of the outcome. (But we're all thankful that it is rare.)

Just for comparison, NNV for flu vaccine to prevent 1 additional outpatient visit or 1additional hospitalization in children 6 - 59 months of age ranged from 12 - 42 and about 1000 - 7000, respectively, in one study.

Novavax Combination Covid-Flu Vaccine Study Allowed to Resume

I mention this item mostly to show how well our vaccine safety oversight is working. This study was paused when 1 phase 2 study participant developed what was initially diagnosed as motor neuropathy (with concern for Guillain-Barre syndrome) but then turned out to be amyotrophic lateral sclerosis, not an inflammatory disorder plausibly related to vaccination. This is one of many mechanisms for detecting evaluating rare events after vaccination. Novavax now can proceed with phase 3 studies.

E. coli O157:H7 Outbreak Numbers Grow ...

... but not related to ongoing infection, simply reflecting a delay in case reporting/verification. CDC and FDA report we are now up to 104 cases spread over 14 states. Of the 98 persons with more detailed information available, 34 were hospitalized and 4 developed hemolytic-uremic syndrome. "Of the 81 people interviewed, 80 (99%) report eating at McDonald's. Seventy-five people were able to remember specific menu items they ate at McDonald's. 63 of 75 people (84%) reported a menu item containing fresh slivered onions."

The case map strongly resembles the distribution map for the suspected onions which are now out of the food chain.

In the meantime, we have another E. coli O157:H7 outbreak, this time associated with carrots. [Correction added 11/18/24: this outbreak is due to E. coli O121, not O157:H7 as originally stated.]

I have a feeling I'm going to be washing my salad items more carefully for a while!

WRIS

The winter season still hasn't started, so I'm reduced to browsing the wastewater maps, all updated through November 14 and current through November 9. Here is maybe a look at things to come. First, here's covid:

Now flu (wastewater only tracks influenza A):

Last but not least, RSV:

I'm a Throwback

When I started practicing medicine, implicit in my professional obligations was the duty to do my best to treat anyone who presented to me, without regard to their backgrounds including race, gender, sex, legal status, and, I guess must be said in today's world, political affiliation. Having practiced in Washington, DC for over 40 years, that last category came up frequently as I encountered parents who were elected officials and/or involved in jobs in the political realm. In keeping with that sentiment, I'll still be keeping politics out of this blog and restrict my pontification to infectious diseases. I'll also avoid commenting on various conspiracy theories and other wild ideas emanating from individuals with no scientific basis for their claims. I will, however, comment on any proposed policies related to pediatric infectious diseases where scientific analysis can enlighten the discussion. Nuff said for now.