yellow fever

What happens when a prominent public figure who thinks he knows everything about everything finds himself in a position to control an important public institution? It's another brave new world we'll need to endure as best we can.

Of course I'm speaking about the Broccoli family ceding creative control of the iconic James Bond franchise to Amazon/MGM, i.e. Jeff Bezos. I shudder at the possibilities of another billionaire-induced stream of havoc.

Er, no. What I'm really referring to is the postponement of this week's meeting of CDC's Advisory Council on Immunization Practices. I had detailed last week that it was scheduled for February 26-28 as one of the three planned meetings this year; the dates are selected well in advance and had been planned through 2027. Not any more, apparently.

These meetings, with the entire public invited to view in real time, were among the most transparent of all healthcare meetings in our country. I'm not sure what public comment accommodations were needed; comments had been requested via the Federal Register as per standard practice, and the draft agenda already included the usual times for live public comments prior to all votes. The concern is that RFK, Jr., will overhaul committee membership to install new members to carry out his anti-science doctrine. The website promises that the ACIP workgroups will still present their findings, but I'm concerned the votes could look much different by the time that happens.

Coupled with potential new rules for FDA and research funding, we could end up with no progress in vaccine development and increasing vaccine hesitancy in the general public. At worst, we may lose access to currently available safe and effective vaccines. The ACIP could cease to be a reliable partner for our nation's health. Private organizations, including the American Academy of Family Physicians, the American Academy of Pediatrics, and the American College of Physicians, among others, may need to step forward to fill the vacuum of discussion and recommendations.

As I step down from my soap box, Ambrose Bierce reminds me, "Speak when you are angry and you will make the best speech you will ever regret.”

Good News Department

After my Debbie Downer impersonation above (did you watch SNL's 50th Anniversary show?), I'm thankful I saw more positives than negatives this past week.

MMWR is Back in Form

The February 20th issue looked a lot more like a typical edition. It had 4 topics and didn't appear to be skimping/censoring information. Of course the biggest news from an infectious diseases standpoint is the report of 2 exclusively indoor pet cats from 2 separate households in Michigan who died from avian flu. Owners of both cats were workers on dairy farms. The cats never had direct exposure to the farms.

The investigation was somewhat limited by incomplete testing. The most logical conclusion is that these 2 episodes represent passage of the virus from humans to cats.

Polio Vaccination Resumes in Gaza

WHO reports another round of polio vaccination is ongoing now in the Gaza strip after wastewater monitoring recently showed a poliovirus spike. Almost 600,000 children under 10 years of age have been identified to receive vaccination through February 26.

Low Dose Yellow Fever Vaccine Produces Similar Seroconversion Rates

At first glance, this might not seem that important to those outside of the yellow fever world. However, yellow fever vaccine is in short supply at a time when this hemorrhagic fever virus is surging in many parts of the world, including the Americas. Investigators published a non-inferiority randomized, double-blind controlled trial of standard dose (13,803 IU) compared to lower doses of 1000, 500, or 250 U administered to adults in Uganda and Kenya.

Using a lower vaccine dose vastly increases the number of people residing in high-risk countries who can be vaccinated. Note that in addition to 29 African countries, 13 countries in Central and South America have some risk of yellow fever transmission.

Listeria Outbreak Linked to Frozen Shakes

Mostly these nutritional supplements are used in long-term care facilities. I haven't noticed any of these products in my local grocery stores. Last Friday FDA reported on the outbreak that first came to light in November 2024 and covers 21 states across the country. Thirty-eight individuals have been infected, resulting in 37 hospitalizations and 11 deaths. The high morbidity and mortality probably relate to the high-risk populations residing in these facilities. If you visit one a nursing home it's worth a mention to the staff to make sure they are aware.

Measles

I'm afraid that reports of vaccine-preventable diseases will increase in the current regulatory and cultural climate. Friday's update from Texas Health and Human Services now lists the total number at a whopping 90 cases, and if news reports are to be believed this is significantly under-reported due to high rates of home schooled children affected. Added to this are 9 cases just across the border in New Mexico, though news reports state there is no known contact to infected individuals in Texas. That seems to be a very unlikely coincidence.

Last week I mentioned that I thought the CDC needed to update their measles tracking page more frequently than monthly, and they listened to me! Now we have updates every Friday.

We haven't broken any records yet, here's hoping Texas officials get this under control soon.

WRIS

It's nice to see the influenza-like illness curve head down this past week, but it could bounce up again like it's done before.

Hospitalizations for confirmed influenza infections also trended down.

Mortality is the highest we've seen since the pandemic. The numbers below include 86 pediatric deaths.

On a national level, covid and RSV aren't doing much, though even low levels result in significant disease.

Bernarr Macfadden

Yeah, I never heard of him either, but opinion columnist Jessica Grose at the NY Times brought him to my attention as a precursor/dopelganger for RFK, Jr. Unfortunately Macfadden's Wikipedia article has too many poorly documented statements to recommend, but what I can verify is that he was a weight-lifter who liked to be photographed showing his muscles (and most of his body) and founded various health movements. A charismatic individual, his influence was prominent from the early 1900s through World War II. He had no medical background. He championed raw milk and denounced white bread and pharmaceutical agents including vaccines. His "movement" reportedly had prominent adherents including Franklin Roosevelt and Rudolph Valentino. Eerily familiar.

As a distraction, I found myself wondering how Jeff Bezos would tilt his newfound power to influence the future of James Bond. I know just the person to play the next villain.

It's nice to be back after my brief website repair hiatus. Please let me know if you have any problems or have any suggestions for the website. I'll continue to work on design issues.

I won't attempt to cover all the issues in pediatric infectious diseases appearing during the hiatus. Needless to say, at lot happened, mostly old news by now. Some newer things I won't mention because they appear only in abstract form at national meetings, such as this month's ID Week (Infectious Diseases Society of America and other ID groups) and the American Society for Tropical Medicine and Hygiene. I have seen dramatic changes from the time data are presented at a meeting, which can be preliminary and incomplete, to the final publication or lack thereof. I've become averse to propagating that type of information source.

Yellow jack is another name for yellow fever; it takes its name from the yellow nautical flag that alerted others that yellow fever was on board. A variation of this flag is still used today to alert other ships about health issues on board. You might want to brush up on your yellow fever knowledge now, keep reading if you're intrigued.

Nirsevimab Supply Chain Flop

This isn't news to any practicing primary pediatric healthcare provider. The supply of the newly-approved long-acting monoclonal antibody preparation to prevent RSV infection for all infants has hit a major snag: demand has far outstripped supply. Maybe we will eventually hear the true story of what happened, but basically we are dealing with a single manufacturer who couldn't produce enough product. Even some hospitals aren't able to get a supply to administer to newborns at the time of discharge.

The AAP has a nice RSV page that healthcare providers may find useful, as well as an October 17 webinar with practical strategies. Remember that maternal RSV vaccination at 32-36 weeks gestation is another option to encourage; talk to preganant people visiting your practices. Palivizumab (Synagis) is still available for high risk infants.

Tripledemic Update

We're certainly not anywhere close to a tripledemic at present. Only RSV seems to be on a significant upswing:

Flu season hasn't yet started for most of the country. COVID-19 disease is much more difficult to track now that our tracking methods have changed so dramatically from the pandemic area. I look to wastewater reports as the most consistent indicator over time, and they suggest that we did not have a big spike this fall.

Future Pandemic Preparedness

The Journal of Infectious Diseases finally got around to publishing a supplement on vaccine and monoclonal antibody development for potential future viral pandemic pathogens. It was put together from presentations at a meeting in 2021. Here's a quick overview of the types of pathogens considered:

Comparison of pandemic potential and countermeasures for viral families known to infect humans. Viral families were categorized as having either low/moderate or high pandemic potential and low/moderate or high levels of existing resources and countermeasures. Cross-comparison revealed 10 viral families with high pandemic potential and low/moderate existing resources or countermeasures upon which the National Institute of Allergy and Infectious Diseases will focus its pandemic preparedness activities. Asterisks denote existing vaccine solutions for some viruses in that family; boldface type, potential vaccine solutions for the entire virus family; shaded box, viral families chosen for prototype pathogen selection.

I'm sure many of these names except for Coronaviridae are unrecognizable to most physicians, and several at best are vague even for infectious diseases specialists. Orthomyxoviridae include influenza viruses. Let's hope research funding comes through for the entities in that lower right box.

You probably haven't thought much about yellow fever unless you've considered travel to an endemic area, either for yourself or for patients in your practice. We have an effective vaccine available, but it is a live virus vaccine. Risks for vaccine side effects increase with age greater than 60; I actually received yellow fever vaccine for travel when I was in this high risk group; more on that later.

A recent Perspective essay in this week's New England Journal of Medicine raised the possibility of yellow fever reappearing in the US, particularly in the southeastern United States. This is already a problem with other mosquito-borne infections like dengue, chikungunya, and Zika viruses. (Note these are in the family Flaviviridae, also included in the gray box above.) The vectors for yellow fever, Aedes aegypti and A. albopictus, are well represented in the US, and their range is increasing as our climate warms.

Yellow fever is endemic in some parts of South America and Africa, and its range appears to be spreading in recent years. (The maps below are a few years old, updated WHO country recommendations usually are published in November.)

Diagnosing yellow fever without a travel history will be very difficult in most instances. In about 85% of those infected, the clinical presentation is a self-limited, nonspecific febrile illness with chills, myalgia, headache, and some GI symptoms lasting about 3 days. An unlucky 15% have a more biphasic presentation with the second stage appearing after around 48 hours of improvement and characterized by more severe symptoms including jaundice, renal failure, coagulopathy, and other life-threatening problems. At that stage the diagnosis might occur to an astute provider and diagnostic testing can be obtained. No specific antiviral therapy is available.

Yellow fever vaccine is highly effective, and a single dose confers life-long immunity. It is relatively safe, but there are rare severe side effects. These severe reactions are 3- to 4-fold higher in vaccine recipients over 60 years of age:

Yellow fever vaccine associated neurologic disease (YEL-AND; mostly encephalitis, Guillain-Barre syndrome):

over 60 years of age = 2.2 cases per 100,000 doses of vaccine administered
less than 60 years of age = 0.8 cases per 100,000 doses of vaccine administered

Yellow fever vaccine associated viscerotropic disease (YEL-AVD; similar to severe infection itself with approximately 50% mortality):

over 60 years of age = 1.2 cases per 100,000 doses of vaccine administered
less than 60 years of age = 0.3 cases per 100,000 doses of vaccine administered

I was over 60 years of age when my travel to Ethiopia caused me to consider yellow fever vaccine. My reasoning wasn't based on the 3- to 4- fold increase in risk, which is a relative risk increase, but rather focused on the absolute risk. This is a topic I've revisited many times in this blog; it has immediately applicability to vaccination of any type but especially for COVID-19 and RSV now.

Adding together the risks for YEL-AND and YEL-AVD for the older population comes to 3.4 cases per 100,000 vaccinations, or 0.0034%. As a comparison, risk of airplane crash is about 1 in 11 million (o.oooo1%) and risk of being struck by lightening is 1 in a million or less (0.0001%). Of course these risks vary by how many miles you spend on airplanes and how often you are out walking around in thunderstorms. Weighing my yellow fever vaccine risks and benefits, I chose to receive the vaccine rather than not travel to Ethiopia where my specific yellow fever risk was very low because I was staying at high altitude for most of the time.

Speaking of Travel

I timed my blog hiatus with a major trip to the Umbria region of Italy. It was a hiking vacation through rural areas with occasional forays into medieval towns and was a wonderful experience. I'm still nursing a few minor musculoskeletal aches and pains - my muscles and joints aren't what they used to be.

In addition to beautiful churches, ruins, and the medieval towns, I was also surprised to see many unfamiliar butterfly species including this Hipparchia hermione example.

Tag: yellow fever

End of an Icon?