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Published on Leave a comment on All Politics is Local

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.

Published on Leave a comment on A Modest Proposal

Quite an eventful week! In general, I try to keep politics out of my commentary, though I fell short of this goal in my February 25, 2024, post where I blasted the Surgeon General of Florida; that may be the only time I've singled out an individual in a negative manner in this blog. Now, I find that his name is being mentioned as the next Secretary of Health and Human Services. All of this reminded me of an almost 300-year-old pamphlet.

But first a bit of the other health news from last week.

Mayaro Virus

In spite of my voracious appetite for medical knowledge, the list of viruses I've never heard of is lengthy. Now my list is one item shorter due to a new report. Mayaro virus is another of the arthropod-transmitted alphaviruses prevalent in parts of South America, causing a febrile illness with severe arthralgias very similar to its cousin Chikungunya virus. Primates serve as a reservoir with the primary vector the mosquito Haemagogus janthinomys. If like me you are a bit shaky on some elements of South American geography and history, Suriname is a former Dutch colony located just north of Brazil and has territorial disputes (in light green) with neighboring countries.

Measles in Vietnam

Vietnam is introducing earlier measles vaccines to try to stem an epidemic. In this WHO Western Pacific region report, you can see Vietnam is going the wrong way in measles incidence. Like the rest of the world, we all "enjoyed" a pandemic period where many traditional infectious diseases transmitted by respiratory routes showed significant declines due to non-pharmaceutical interventions, only to now reappear in greater numbers. For measles, Vietnam showed an incidence of 7.4/million population in 2020, dropping to 0.3 in 2022 but now back up to 7.1/million in 2024.

Normally Vietnam recommends measles immunization at 9 months of age, but now this is being dropped to 6 months due to an increase in cases in younger age groups. (You'll need Google translate for this link.)

Computerized Radiograph Interpretation for TB?

Although this study was performed only in adults, I thought it was worth mentioning as a possible glimpse of the future. Investigators in Africa and southeast Asia looked at the performance of a computer program to interpret chest radiographs in about 1400 adults with cough > 2 weeks in duration and found the program to have significantly higher sensitivity than a relatively new blood test for host response gene activation in TB as well as superior to CRP. When trying to diagnose TB in resource-poor settings that may not have access to good molecular and other microbiologic methods for TB diagnosis, we need every tool available. I'll be interested to see how newer methods for TB diagnosis evolve.

More on Bird Flu

CDC reported that 7% of 115 dairy workers at farms known to have infected cows showed serologic evidence of influenza A H5N1 infection. Four of the 8 seropositive workers did not recall having any respiratory signs or symptoms since the cows were first noted to be sick. This rate wasn't terribly different from the 60% of those with no illness history in the seronegative group. Given that H5N1 so far seems to be a mild illness in humans, the finding of asymptomatic infection isn't surprising. Clearly we need a lot more data on human illness in these and other settings.

Benefits of Quadrivalent Meningococcal Vaccine

Of our recommended vaccines, meningococcal vaccine probably has the lowest "return on investment." Meningococcal disease is relatively rare but comes with very high morbidity and mortality when it does occur. This modeling study estimated the number of cases of invasive meningococcal disease in 11-23 year-olds prevented by vaccination during the period 2005-2021. One always needs to take modeling studies with a grain of salt because they by necessity make a lot of assumptions. The authors did a good job of trying to look at all possibilities. They concluded that "vaccination averted an estimated 16 (95% CrI, 8-31) deaths among adolescents aged 11 to 15 years and 38 (95% CrI, 19-75) deaths among those aged 16 to 23 years." I guess those are small numbers when compared to the entire US population, but this is still a meaningful benefit.

WRIS

Things are still relatively quiet, though with regional variations.

I did happen to note that wastewater levels of RSV are very high in Maryland, so maybe that will be the first pathogen to increase in my region.

Make America Healthy Again

I feel like the MAHA acronym was one of the nicer-sounding political slogans to appear recently. However, the fact that it was popularized by a notorious pseudo-science fringer concerns me for what might lie behind MAHA. That made me recall a short treatise by Jonathan Swift (of Gulliver's Travels fame) that I came across a long time ago. I read it again a few times this week, and this highly satirical essay entitled "A Modest Proposal" is worth 10 or 15 minutes of your time. I think it is best read without knowing where the narrator is going, so I'll give you a SPOILER ALERT. You can read the original document in the link now, before reading what I write below, or you can just forego the surprise and keep on with my take below.

The narrator beings with an "objective" view of the problem, in 18th century Ireland, of the economic woes of a large section of the populace. He particularly hones in on the difficulties that parents in lower economic strata have in providing for their children. After going through some numbers assumptions that we can only guess at the accuracy, he decides that Ireland has about 120,000 children born to impoverished parents annually. How can the country solve this problem? He offers his modest proposal, or "humble solution:" It's a sudden turn in tone, to say the least.

"I have been assured by a very knowing American of my acquaintance in London, that a young healthy child well nursed, is, at a year old, a most delicious nourishing and wholesome food, whether stewed, roasted, baked, or boiled; and I make no doubt that it will equally serve in a fricasee, or a ragoust."

Yes, Mr. Swift in his satirical essay is proposing cannibalism as a solution to poor families trying to raise their children. He goes on to describe various details of preparation and serving.

MAHA sounds OK now, but I fear of this becoming another modest proposal. I'll withhold my judgment until we see more details of the plan.

Published on Leave a comment on My Hebdomadal Habit

One of the many reasons I love to read is to discover new words to add to my vocabulary. Reading Colin Dexter reminds me of the need to keep a dictionary close by.

WRIS

The US Winter Respiratory Infection Season hasn't started yet; activity is low to minimal everywhere.

Note that the map above is a new twist from CDC: rather than "Influenza-Like Illness" activity, this reflects all acute respiratory illness by not requiring fever in the definition. So, it probably picks up more of all those other respiratory viruses out there. For the 2 graphs below, just use the same link above and scroll down.

Percentage of ED visits due to the "big 3" viruses is minimal, with covid dropping dramatically.

Since I'm trying to figure out the best timing for my own flu shot, I looked at influenza A wastewater tracking:

Only Rhode Island makes it to moderate activity, all the others with data are minimal or low. Probably the key part of the map above is the number of hatched/limited coverage states. For example, New York flu A wastewater activity only includes Albany and Rochester, not much help to the New York City folks.

Given the WRIS lull, clinicians might be interested in a recent CDC overview of covid and flu management. I couldn't log on to the live presentation but reviewed the slides and took the test for (free) CME credit. The presentation was well done, I recommend it as a good review.

Forbear the Bear (Meat)

Not that long ago (5/24/24 post) I relayed a CDC report about a 2022 trichinellosis outbreak linked to frozen Canadian bear meat. Less than 5 months later, CDC is telling us about another one, this time from 2023 at a single "feast" in North Carolina. It doesn't have as much detail as the earlier report, we don't know much about the food preparation methods and none of the ill persons returned for confirmatory lab testing. It certainly sounds like trichinellosis, however; in addition to a nonspecific febrile illness, 9 of the 10 probable cases reported facial swelling which for me is a T. spiralis infection clue.

I visited a number of wild game/hunting sites to see what advice consumers of bear meat might see. Most sites correctly cautioned hunters to cook bear meat to at least 165 F internal temperature, but a few did not. Also, many mentioned other wild game meats that taste better than bear meat. I won't be ordering bear meat anytime soon, but if you are drawn to the experience check out the CDC web site or this advice from Massachusetts that also includes recipes!

Travel to Rwanda?

Last week I mentioned the Marburg virus outbreak in Rwanda, and this past week CDC upgraded a travel alert for the area which has caused quite a kerfuffle. Rwanda now has a CDC level 3 travel alert status, meaning that nonessential travel to the area should be reconsidered. Three days after the CDC advisory, WHO pushed back. WHO believes that travel restrictions will be ineffective in controlling the outbreak plus may prove harmful to local economies and serve as a disincentive for sharing of public health data from those countries, harming control efforts. These are valid concerns; choosing the proper course of action probably requires something approaching the wisdom of Solomon.

Also, an experimental Marburg vaccine has made its way to Rwanda, now primarily being used and studied in health care providers who form the bulk of new cases, plus other high risk individuals. This study is of extreme importance, and I'm hopeful that we'll see good data eventually.

OED

For a brief moment in my past, I longed to have a complete print version of the Oxford English Dictionary at my elbow. It was short-lived: the standard version comes in 20 volumes and now lists for $1000+. A bargain is the "compact" version at about half that price; it is a "photo reduction" of the original, with 9 pages of the original on each single page. It comes with its own magnifying glass.

It's a lot easier to just look at the online OED to find out that hebdomadal means "weekly." I also learned that it's not commonly used, fewer than 0.01 occurrences per million words in modern written English. Maybe I've now bumped that up to 0.02.

Dexter's Inspector Morse character, in his second installment entitled Last Seen Wearing, mentions his "regular hebdomadal debate" when faced with his weekly dilemma of whether to purchase the more cultured Sunday Times versus the coarse News of the World at the newsstand. I can see parallels to my own cultural preferences in literature, music, and art. However, the hebdomadal part of my habits clearly is this blog. Any further resemblance to Inspector Morse ends here though; he is a true, albeit fictional, polymath who happens to be a detective. I am a real-life physician who happens to have diverse interests, like most of us.

Published on Leave a comment on Winding Down (Again)

After one failed retirement attempt, I'm trying again. I just entered a new phase to decrease my coverage of inpatient telemedicine services at regional hospitals and, if demand isn't increasing terribly, I'll phase out completely. In the meantime, I'm revving up for watching the Winter Respiratory Infection Season (WRIS).

WRIS

Nothing strikingly new or concerning on the covid, influenza, and RSV fronts, according to CDC. Respiratory illnesses, wastewater levels, and ED visits are pretty flat or decreasing most places. Florida is starting to show an increase in RSV; typically that region starts sooner than the rest of the country. Of course all viral activity varies geographically, and you can look at your own region with CDC's interactive program at that link.

I admit to having some personal interest in following this closely now. I'm trying to figure out timing of my flu vaccine; as a septuagenerian I may have more rapid waning of immunity after vaccination than do younger generations, plus preliminary data from the Southern Hemisphere suggests a slightly lower flu vaccine effectiveness this year. The key term here is preliminary. These estimates are based on very low sample sizes, and estimates always change once the full season can be evaluated.

Speaking of vaccines, the UK provided a more straightforward guidance for covid vaccination this year. The eligibility groups are pretty limited:

During the 2024 autumn campaign the following groups should be offered a COVID-19 vaccine:

  • all adults aged 65 years and over including individuals aged 64 who will have their 65th birthday before the campaign ends (31st March 2025)
  • residents in a care home for older adults
  • individuals aged 6 months and over who are in a clinical risk group, as defined in tables 3 and 4 of the Green Book chapter 14a

As I've mentioned before, the UK with its National Health Service relies heavily on cost effectiveness analyses, leading to a more restricted target population than in the US.

Two Viruses on the International Scene ...

Marburg Virus in Rwanda

Marburg activity in Rwanda is increasing, and the CDC sent out an advisory last week. Marburg virus is another of the hemorrhagic fever flaviviruses, like Ebola; it has a high fatality rate. As in other hemorrhagic fever virus outbreaks, healthcare workers are at high risk if they are not careful with exposure to blood and body fluids. Most of us remember the spread of Ebola to the US, and already there's been a scare in Hamburg, Germany, but the ill traveler returning from Rwanda tested negative. The name comes from the German city of Marburg which was one of the sites (the others were Frankfurt, Germany, and Belgrade in what is now Serbia) of laboratory outbreaks of the illness in 1967, linked to African green monkeys imported from Uganda. Let's hope efforts to contain the infection are successful, but it's a tough task in low-resource regions.

Perinatal Chikungunya

A new study from Brazil suggests a relatively high rate of transmission of this virus from pregnant people to their newborn infants. The study period covered the years 2016 - 2020. Here's the summary numbers:

Symptoms in infected infants included, in addition to rash and fever, some more severe conditions like DIC, vesiculobullous eruption, seizure and encephalitis, and respiratory failure. It was both a retrospective and prospective case series, and I learned a new term: ambispective!

... But Also Some International Success

The WHO recently declared Brazil has successfully eliminated lymphatic filariasis as a public health problem, a major milestone. The only countries successful previously with filariasis were Malawi and Togo in the WHO African region; Egypt and Yemen in the Eastern Mediterranean region; Bangladesh, Maldives, Sri Lanka, and Thailand in the South-East Asian region; and Cambodia, Cook Islands, Kiribati, Lao People's Democratic Republic, Marshall Islands, Niue, Pilau, Tonga, Vanuatu, Viet Nam, and Wallis and Futuna in the Western Pacific region. Time to dig out that world map!

Filariasis is one of 20 Neglected Tropical Diseases targeted by WHO for improved control by 2030.

Lower Vaccination Rates in US Kindergartners

CDC updated vaccine coverage rates for the 2023-2024 year and, no surprise, it's dropping. The decrease may be driven at least in part by an increase in non-medical exemptions. This news doesn't bode well for future outbreaks of vaccine-preventable diseases, but the clinical impact is largely determined by geographic distributions at the community level. The site has a lot of data, worth some browsing, but here's a quick look at MMR coverage by state for 2023-2024:

Any state that isn't the darkest blue has high risk for outbreaks. Even within the dark blue states any pockets of poor vaccine coverage, such as communities or schools that have high rates of vaccine-averse parents, could see outbreaks.

How's Your Outpatient Antibiotic Prescribing Score?

A cross-sectional database study of about half a million antibiotic subscriptions in 2022 from Tennessee showed some interesting results. The investigators looked at both appropriateness of antibiotic choice and duration of treatment; only 31% of prescriptions were appropriate for both. Here's the quick look at optimal antibiotic choice by disease:

Here's what it looked like for duration of therapy. Standard durations reflect current guidelines, whereas contemporary durations are taken from more recent studies suggesting shorter courses are effective. The number of days in parentheses are the contemporary durations.

Again, another study worthy of browsing if you commonly prescribe antibiotics for these conditions.

November 5 is Fast Approaching

Although I'm trying to wind down my practice, it seems like my to-do list is twice as long now. We're all busy, but please don't forget to vote!

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Published on 2 Comments on Happy Autumnal Equinox

It's been an eventful week for me but relatively quiet in the world of infectious diseases. I've just returned from a week's trek in the semi-wilds of Colorado. You may recall that last week's post included a mention of mosquitoes and high altitudes, noting that climate warming has been accompanied by trends of more mosquitoes at those upper elevation. I'm happy to report that after spending the week in the great outdoors at 5000 - 10,000 feet I only had a few bites and didn't even touch my insect repellent.

Turning skyward, I was able to view the September 17 partial lunar eclipse from Mesa Verde National Park; sadly my antique cell phone camera was unable to capture it. This morning I consulted my trusted 2024 print edition of The Old Farmer's Almanac to remind myself of the difference between an equinox and a solstice. The earth's axis is tilted at 23.5 degrees from the perpendicular as it revolves around the sun, and the equinoxes occur when both northern and southern hemispheres equally face the sun. Northern hemisphere solstices occur when the North Pole is most tilted towards (winter) or away (summer) from the sun. I learned so much this week!

Pertussis

Whooping cough was in the news recently, though really this is just a return to "normal" after the pandemic years. Here's the long view from CDC data.

On a more recent view, you can see the age breakdown.

I was involved in pertussis immunology and vaccine research very briefly in my career. I always like to mention an oldie-but-goodie article from 1992 showing that about one-quarter of UCLA college students with cough lasting longer than 5 days showed evidence of recent pertussis infection. It's a good reminder that pertussis in adults usually looks very different, and milder, than the classical whooping cough in infants. Diagnosis is difficult unless you think about pertussis as a possbility.

Maybe not so coincidentally with these news reports, the FDA VRBPAC meeting last Friday focused on using Controlled Human Infection Models (CHIMs) to try to develop a better pertussis vaccine. Yes, that's right, intentional infection of human volunteers to study various aspects of the disease. We need more information to improve pertussis control, given that our current acellular vaccines are less effective (but also with less side effects) than the predecessor whole cell vaccines. Large scale trials are difficult, expensive, and largely impractical in the present era, so it's time for new approaches. A group at the University of Southhampton in the UK presented some preliminary data from a CHIMs trial and also had a nice graph to put into perspective relative mortalities and contagiousness of pertussis compared to other pathogens:

The study itself was just a challenge study of human volunteers to determine the dose of organisms and the immunologic responses surrounding infection and colonization. It seems likely that these types of studies will be utilized more frequently in the future to improve our understanding of pertussis prevention.

Needless to say, I didn't join this meeting live, I was off the grid in Colorado, but I did skim through the recording and slides today. This wasn't a typical VRBPAC meeting where voting occurred, it was more of a discussion to guide future research.

More Wastewater

Speaking of returning to pre-pandemic levels of infection, I've been watching wastewater trends for enterovirus D68. You may recall that this was an enterovirus strain that figured prominently, but not exclusively, in outbreaks of acute flaccid myelitis that tended to occur in even-numbered years - pretty strange.

As you can see, the pandemic really ended this pattern, and nothing new is going on so far this year. However, wastewater numbers, at least for EV D68, have looked very different.

Will we see a blip upwards in AFM cases this year? I hope not.

More Colorado Learning

My landscape designer wife clued me in to the details of the quaking aspens, so named due to the fluttering of the leaves that have their own distinct sound. They are beautiful, both my wife and I wished we had better pictures to show you.

On another note, although I love to learn, one new factoid I happened upon was perhaps less exciting. Hiking at these altitudes, I learned that I'm not as young as I used to be!

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