COVID-19 – Page 2 – Pediatric Infection Connection

Tirade Time

Bud WiedermannSeptember 8, 2024September 8, 2024Leave a comment

It's unusually cool today in the Washington, DC, area, prompting my landscape designer wife to don her poison ivy hunting apparel and venture into the nether regions of our back yard to keep it safe for us.

We've had a lighter week in infectious diseases events. I'll take advantage of that to share a rare criticism of one of my favorite ID feeds. But first .....

Leptospirosis

This is a tough diagnosis most of the time; it's a relatively uncommon infection in the US, and the early stages don't have particularly novel signs and symptoms; it's just a nonspecific febrile illness. About 10% of cases can progress to a second and more severe stage, often called Weil's disease. It's important to remember that it can be a water-borne pathogen, as illustrated by these 2 recent reports.

First, this week's MMWR provides us with documentation of the leptospirosis outbreak in Puerto Rico following Hurricane Fiona in 2022. Leptospirosis is endemic in parts of Puerto Rico, and a disruption like flooding due to a hurricane increases its reach and can result in disease spikes. Look at these graphs of weekly rainfall and leptospirosis cases - it certainly fixes in my mind the tie between water and leptospirosis.

The MMWR article has a link to a nice clinician fact sheet.

Similarly, there's a new spike in leptospirosis infections in Thailand, so far just in news reports (you'll need Google translate again).

I first took a deep dive into leptospirosis as a medical student when I came upon a landmark article of detective work surrounding an outbreak in St. Louis. Two of the authors were mentors of mine, and they loved to regale me with (probably augmented) tales of tracking rats through the sewers of St. Louis. I'm sure this contributed to my choice of pediatric infectious diseases as a career, though not to the extent that I've chased sewer rats.

Mixed Messages About Vaccine Protection From Long Covid

A new article reached a different conclusion from several other reports showing that covid vaccination is somewhat protective against long covid, now better termed PASC (Post-Acute Sequelae of COVID-19). The new study is a retrospective cohort study mining an administrative database from a single (large) healthcare system. The bottom line is (of course!) towards the bottom of the table: no real differences in PASC rates based on vaccine status. Also note this was primarily a study of adults.

Is this a flawed study? Are the authors' conclusions wrong? Well, no to both. We will have differences in conclusions from such studies primarily when we are seeing retrospective studies that rely on administrative databases. The authors did a heroic job of attempting to adjust for various errors in how such data is recorded, but it's impossible to account for everything. Thus, we can have errors in diagnosis, diagnostic code assignment, and missing data, among other issues. Couple that with different definitions of PASC and the likely heterogenous pathogenesis of different forms of PASC, and it's a recipe for conflicting study results. I think we likely will have a clearer picture of PASC, including whether covid vaccination can offer some protection, but it will take prospective longitudinal studies which require more time for data collection and analysis. A longer discussion of the science of PASC is reviewed in Nature Medicine. In the meantime, studies like this one help us fine tune future studies.

Shame on CIDRAP

CIDRAP (Center for Infectious Disease and Research Policy at the University of Minnesota) is one of my favorite daily feeds. I think they blew it in mentioning FDA clearance of a new Lyme test; not only is it not newsworthy, but it could lead some individuals to chase harmful Lyme disease testing. I could be guilty of the same by even mentioning it here.

First of all, FDA clearance of diagnostic tests is a relatively low bar to clear. Although I couldn't find any FDA commentary on the test in question (I guess that would require a Freedom of Information Act request), I did link to the criteria that I think likely were used in this setting, because the particular methodology this test utilizes is nothing new. So, I believe the manufacturer would only need to show "substantial equivalence" to existing tests. This is not the same as showing the new test improved diagnostic accuracy or improved healthcare outcomes. Here's the summary of applicable FDA guidance:

"Studies to Demonstrate Substantial Equivalence

The types of studies typically used to demonstrate substantial equivalence may include the following:

In the majority of cases, analytical studies using clinical samples (sometimes supplemented by carefully selected artificial samples) are sufficient.
For some IVDs, the link between analytical performance and clinical performance is not well defined. In these circumstances, clinical information may be warranted.
FDA rarely requires prospective clinical studies for IVDs, but regularly requests clinical samples with sufficient laboratory and/or clinical characterization to allow an assessment of the clinical validity of a new device. This is usually expressed in terms of clinical sensitivity and clinical specificity or agreement."

This new Lyme test is simply an immunoblot, a very common type of test utilized in multiple settings but with the drawback that interpretation is somewhat subjective - a human needs to decide if a band is prominent enough to be considered present.

When I dug deeper to find supporting studies for this particular test, I became more alarmed. While there are some preliminary studies that I think might have used this new immunoblot method, they don't answer any clinical performance questions. More worrisome is that the test will be sold by a California lab called IGeneX, a company that offers many Lyme tests that, in my opinion, have falsely diagnosed many of my patients with Lyme disease. They often rely on their own interpretations of what constitutes a positive test and provide no reliable scientific evidence to suggest their methodology is valid. In fact, the press release for this new test stated that "Results interpretation is based upon new criteria and not CDC criteria."

Even now on their website they steer providers and patients away from the standardized two-tier testing preferred by CDC. Here's a quote from the IGeneX website: "Lyme disease is typically diagnosed by a two-tiered testing (TTT) approach involving an enzyme-linked immunosorbent assay (ELISA) followed by a Western blot test. However, the sensitivity of these commercially available tests is poor, meaning they can miss active infections. Experts advise against this testing technique due to the ambiguity of its results." It's easy to find a so-called expert to say anything. Again, in my opinion, this lab is to be avoided, and you'll notice I didn't provide a link to them. I'm disappointed CIDRAP gave them free publicity.

Lyme disease testing is far from ideal, and it's certainly possible this new test is an improvement, though I doubt it. CDC explains diagnostic testing for Lyme disease, including the recommended two-tiered testing options. I suspect IGeneX might try to claim that their new immunoblot can fulfill CDC recommendations, but I'm concerned that they will use unsubstantiated rules for interpretation of a positive immunoblot result, as they have for similar tests in their lab.

COVID Crystal Ball

Last week my wife and I got our new covid vaccines, more based on upcoming travel plans rather than any immediate concerns about getting covid. In fact, things seem to be winding down. According to the latest CDC clairvoyance, "we estimate that COVID-19 infections are growing or likely growing in 7 states, declining or likely declining in 16 states, and are stable or uncertain in 25 states." (Not a totally reassuring conviction if half the states could be uncertain!)

I couldn't find a separate precise definition of cutoffs for their categories, but from viewing the data it appears that the Stable or Uncertain category is defined as a probability that the epidemic is growing in those states as between 0.5 and 0.75. By comparison, all the Growing states had probabilities of 0.93 and above.

Curmudgeon-in-Residence

I think I've paid my dues long enough to be entitled to curmudgeon status. The new Lyme test thing reminded me of my dismay that some of the children I've seen in my practice over the years were harmed by use of misleading diagnostic tests resulting in prolonged and unnecessary antibiotic use. I wear my Statler and Waldorf credentials proudly. I think I bear more of a resemblance to Statler.

Now, to cool off a bit, I'll take a quick stroll in my (safer) back yard.

“There never was a good war or a bad peace.” 2

Bud WiedermannAugust 18, 2024August 18, 20242 Comments

This quote from a Benjamin Franklin letter written 241 years ago still rings true. It's not hard to list bad traits of war, but I find that sometimes we overlook war's contribution to infectious disease outbreaks. Now we're seeing yet another example of this that could expand if not controlled.

Last week revealed a bundle of things to mention, I've tried to trim the list as best I could.

Oropouche HAN

Now the CDC has jumped on the Oropouche virus bandwagon with a new alert via the Health Alert Network. Most useful to front line healthcare providers is an approach for when to consider Oropouche infection more likely:

Consider Oropouche virus infection in a patient who has been in an area with documented or suspected Oropouche virus circulation within 2 weeks of initial symptom onset (as patients may experience recurrent symptoms), and the following:
- Abrupt onset of reported fever, headache, and one or more of the following: myalgia, arthralgia, photophobia, retroorbital/eye pain, or signs and symptoms of neuroinvasive disease (e.g., stiff neck, altered mental status, seizures, limb weakness, or cerebrospinal fluid pleocytosis); AND
- No respiratory symptoms (e.g., cough, rhinorrhea, shortness of breath); AND
- Tested negative for other possible diseases, in particular dengue. If strong suspicion of Oropouche virus disease exists based on the patient’s clinical features and history of travel to an area with virus circulation, do not wait for negative testing for other infections before contacting your state, tribal, local, or territorial health department.

As I've said previously, it's a clinical syndrome similar to dengue or chikungunya; note the absence of prominent respiratory symptoms. Cuba and Brazil travel has been associated with imported Oropouche in other countries; the disease is also experiencing a rise in Colombia, Peru, and Bolivia.

Mpox

Similarly, we now have mpox reported from Sweden in a traveler returning from an area of Africa where clade I disease has been active. Details are scant, but it was certainly only a matter of time before this happened. Clade I seems to have a higher mortality rate than the more common clade II variant, but it's hard to get precise numbers, much less whether anything is different about the clade Ib variant now being seen. Transmission epidemiology seems to be slightly different than the clade II epidemic of a couple years ago which stemmed primarily from men who have sex with men. In this year's clade I iteration, infections also are being spread by heterosexual encounters, usually via sex workers, and also within households. Young children and pregnant women are at highest risk for complications including fatal outcomes. Like most sexually transmitted infections, public health measures are hindered by infected people not being willing to disclose their sexual contacts. In the Democratic Republic of Congo, the epicenter of the clade I outbreak, homosexuality is not officially illegal but societal norms in the DRC are not favorable to LGBT individuals.

Effective mpox vaccines exist for preventive measures, but a recent press release from the NIH had discouraging news about antiviral therapy. Tecovirimat, aka TPOXX, had been useful in clade II disease. Now, in a placebo-controlled randomized trial of almost 600 mpox-infected subjects in the DRC, tecovirimat outcomes for mortality and for time to improvement were the same as with placebo recipients. I'd like to see the actual study results, but I tend to trust NIH press releases more than most others. CDC has a nice update and map.

Parvovirus B19 Alert

Parvo B19 infection isn't a notifiable disease in the US, so if concern has arisen it usually means something dramatic is going on. This week CDC issued a HAN notice about this infection. The disease is well known to pediatric healthcare providers and to many parents as erythema infectiosum or fifth disease. It's a minor illness unless a pregnant person is infected, with subsequent risk of miscarriage or severe fetal anemia and non-immune hydrops fetalis. Individuals with chronic hemolytic conditions are at risk for aplastic crisis and severe anemia, and immunocompromised people have higher risk of complications. Read more if you need a refresher.

Is It Time for Universal Screening for Congenital CMV?

Last week's MMWR reported on the first 12 months' experience with Minnesota's universal newborn screening program for cCMV; it began in February 2023. 184 of 60,115 (0.31%) newborns screened on a dried blood spot had positive CMV results. Note that screening dried blood spots is less sensitive than other methods; 3 infants with cCMV with negative blood spot results and were picked up by other means. Buried in the report was the interesting finding that of 11 infants with permanent hearing loss, 4 passed their hearing screening test as newborns. Clearly we need more than universal hearing screening to identify at-risk infants. I look forward to further outcome data on Minnesota's program.

Dinner at the Sick Restaurant (apologies to Anne Tyler)

I like to think of myself as an adventuresome diner, but probably I would have drawn the line at these 2 delicacies I found at ProMED, the listserv I've used for decades.

Chicken liver sashimi is a new one on me, but now linked to an outbreak of campylobacteriosis in Japan. (You'll need Google translate for this one.) Perhaps slightly less disgusting is the idea of smoked non-eviscerated fish. Recent testing found a commercial product potentially contaminated with botulinum spores; thankfully no clinical cases have been reported. I've eaten sardines from a can. They also are non-eviscerated, but apparently the fish reported this week were capelin and exceeded the length allowable for packaging non-eviscerated fish. The product was produced and distributed by a company in Florida.

Covid

Meanwhile, let's not forget about our old friend. National wastewater levels are still up.

Levels might be tapering off in some parts of the country.

Meanwhile, clinical indicators suggest we're going to be seeing increasing cases the next few weeks at least. Here's an example with percent test positivity from the same link as above. It's a little higher than it was a year ago, though it's difficult to compare time periods since different factors now drive test-seeking behavior.

Meanwhile, if we can believe news reports (the FDA can't disclose approvals ahead of time), the new KP.2 variant-based mRNA covid vaccines should be available later this week. The Novavax vaccine presumably will be ready a little later. Timing for when to get the new vaccine should be based on individual considerations, including immunocompromised state, travel plans, and other factors. However, trying to predict the amount of covid activity over the coming months is only slightly better informed than a roll of the dice. Here's the current forecast from CDC.

Polio in Gaza

Not that it's unexpected, but a case of polio has been reported in a 10-month-old child in Gaza. This child would have been born just near the start of the new war and presumably was never immunized. Breakdowns in the health system as well as with clean water and sanitation are ideal for a reappearance of polio; it hasn't been seen in Gaza in 25 years. The UN has called for a "polio pause" to allow vaccine distribution. I try to avoid political statements in this blog, and I won't change that now, but I think my old friend Ben Franklin had it right about war.

Batesian Mimicry

To end on a lighter note, when I first saw this term I immediately thought of Norman Bates and "Psycho," perhaps Hitchcock's most famous movie. But no, it's not (spoiler alert) Norman mimicking his mother. This refers to Henry Lewis Bates' 1862 publication on butterflies in the Amazon. For an easier read, try this Wikipedia page. It explains my astonished update in last week's post that the mysterious black butterfly in our garden was in fact a dark variant of the easily recognized tiger swallowtail. Apparently it is an example of Batesian mimicry whereby a vulnerable butterfly species develops the ability to mimic a less desirable (to predators) butterfly. In this case, the tiger swallowtail mimics the unpalatable and toxic pipevine swallowtail. I mentioned last week that I had probably forgotten a lot about what I learned about butterflies in my childhood. I certainly don't remember anything about Batesian mimicry or dark tiger swallowtails. Needless to say, I've been down a rabbit hole all week about this. When I went back to my 3 texts on butterflies, all mentioned the black variant in the tiger swallowtail section but not in the sections on black-colored swallowtails where I was looking. As you can see below taken from "Mimicry and the Swallowtails," they are very different but in fact have subtle similarities that escaped me.

Summer Sleuthing 2

Bud WiedermannAugust 11, 2024August 11, 20242 Comments

Last week I mentioned I'd make a poor politician or salesman. I didn't mention other professions, but I wonder if I might have been a successful detective. I had a consult last week that took all of my sleuthing skills, a newborn exposed to maternal syphilis that required me to track down mother's history dating back to 2017 as well as a sibling who turned out to have been a patient of mine a few years ago - not the type of continuity of care I'm looking for. This newborn, like the sibling, will need IV penicillin treatment but most likely will be fine in the long run. The entire consult took me about 2 hours compared to my usual 1 hour. That's why pediatric ID docs are at the bottom end of physician reimbursement but also why I love the profession.

I've been involved in some other detective work recently, but first a review of what's bubbling up as summer is winding down.

More Oropouche Concerns

This is a stark example of today's world - no matter where an infectious disease outbreak occurs, it can affect all of us. The European Centre for Disease Prevention and Control has issued a travel alert for countries in Central and South America experiencing epidemic Oropouche virus disease. The EUCPC found 19 cases of Oropouche disease in European Union residents this year, all linked to travel to Cuba or Brazil. No such alert has been issued by the US CDC, but US citizens should take note.

Summer travel planning should include assessment of disease and other safety risks in foreign countries.

Mpox Redux

I had hoped mpox had settled into a mostly endemic situation in the US, which is in itself a defeat of sorts, but new concerns have arisen from the outbreak in the Democratic Republic of the Congo that could extend to the US. The CDC's Health Alert Network has issued a new alert as cases spill over from the DRC to neighboring Burundi, Rwanda, and Uganda. The clade involved, clade I, is more transmissible and perhaps has a higher mortality than the more common clade II. Risk of exportation to the US is still considered low due to infrequency of commercial air flights from these countries. The alert contains details for case management. Remember, at risk individuals (see below) should receive 2 doses of mpox vaccine.

Persons at risk:

Gay, bisexual, and other men who have sex with men, transgender or nonbinary people who in the past 6 months have had one of the following:
- A new diagnosis of ≥1 sexually transmitted disease
- More than one sex partner
- Sex at a commercial sex venue
- Sex in association with a large public event in a geographic area where mpox transmission is occurring
Sexual partners of persons with the risks described in above
Persons who anticipate experiencing any of the above

Benefits of Vaccination

Speaking of vaccinations and CDC, the latest MMWR included an article estimating benefits, both economic and clinical, of childhood vaccinations over the period 1994-2023. One always needs to be wary of this type of modeling which by its very nature requires analysis of large administrative databases that can have some errors. However, the study authors were very careful and listed 4 study limitations.

First, the analysis didn't include influenza, covid, or RSV vaccination; we can all agree that would result in an underestimation of benefits. They also felt that the recorded immunization rates could be an underestimate, which in turn would underestimate costs of the programs. Similarly, the cost estimates didn't include federal, state, or local program management costs or excise taxes. Their fourth limitation point was that they were unable to consider contributions of other factors like hygiene or social distancing which could have lowered disease rates independently of vaccines. So, of the 4 limitations, 3 could result in overstatement of vaccine benefit. With those caveats, here are their numbers:

That's over a million deaths prevented and over 2 trillion dollars in societal savings.

Sniffles Status

We're still talking covid here, with flu and RSV almost nonexistent. Here's the latest ED visit numbers from CDC.

I was hoping covid wastewater would start to level off, but it is rising in all parts of the US (same link as above).

So, expect more covid in the coming weeks. For now, it seems we are stuck with both summer/early fall and winter covid surges.

Hieronymus Bosch

Not the painter but rather the seriously flawed detective character created by Michael Connelly. Probably the same fondness I have for the detective-like nature of pediatric infectious diseases practice also draws me to (mostly) noir detective literature. This summer I decided to look into somewhat more recent (compared to 1920s-1950s) detective series. Colin Dexter's first book in the Inspector Morse series, Last Bus to Woodstock (1975) was enjoyable, and I'll probably continue to the next installment. Now I've started the first book in the Harry Bosch series, Black Echo (1992). Both books are littered with beautiful writing, such as this musing by Bosch: "The sky was the color of bleached jeans and the air was invisible and clean and smelled like fresh green peppers."

I thought about that line as I was outside in the garden trying to figure out what species of butterfly was sampling the Joe-Pye-weed. I have a love of butterflies dating back to my childhood in south Texas, though I've forgotten almost everything I've learned from that time. We don't have nearly as many butterfly species in Maryland as in my home town, but it's still fun to watch and study them. This one black butterfly has been hanging around for several days; in fact, it's right outside my window now. Unfortunately I can't decide if it is the somewhat more common black swallowtail (Papilio polyxenes) or the rarer spicebush swallowtail (Papilio troilus). Real butterflies often don't look exactly like their pictures in reference materials. After several days and about 15 photos of different aspects of the wings and thorax, I decided to surrender and ask BAMONA (Butterflies and Moths of North America). I've submitted photos, dates, locations, and behavior details and now waiting on a reply from an expert. I'll let you know if they reply.

STOP THE PRESSES: BAMONA just sent me a reply, moments after my initial posting. It is a "dark-form female P. glaucus." For the uninitiated, this is the tiger swallowtail, but the picture below looks nothing like the typical tiger swallowtail. Also amazing, my iPhone identified the photo as P. glaucus, which I laughed as being another failure of artificial intelligence. You can bet I'll be reading more about this dark form butterfly.

Joys of Summer Bites

Bud WiedermannJuly 28, 2024July 28, 2024Leave a comment

The one or two regular readers of this blog know that I'm a favorite companion at outdoor summer activities, not because of my scintillating conversational repartee but rather due to my fabulous mosquto/gnat magnet properties. No one near me needs to worry about bug bites; all those bloodsuckers are feasting on me. One morning this week I gathered a couple dozen bites in a very short time and have been scratching ever since. I've been waiting for symptoms of West Nile virus infection, nothing so far. Meanwhile, another vector-borne disease may have worse consequences than previously known.

But first, ...

Covid Summer Surge

In spite of many breathless news reports, this is still nothing to get worked up about, other than for high-risk individuals to consider returning to masking in crowded indoor spaces and employing other mitigation strategies. Some of the lay reports seem to forget that wastewater levels are not the same as actual infections. Wastewater covid detections might be decreasing, especially in the West.

Percentage of emergency department visits due to Covid, one rough measure of clinical illness, is increasing though still at low levels.

Meanwhile, we have a little more clarity on one aspect of long covid. In one study, myalgic encephalitis/chronic fatigue syndrome in adults was no more common following covid than following an acute infection-like illness that was negative for covid. I've long been concerned that case definitions and studies haven't been focused on the heterogeneity of long covid. Fortunately, some studies are geared to looking at the ME/CFS cases separately from post-covid symptoms that might be related to end-organ damage persisting after severe pulmonary or other infection.

Avian Flu

Similarly, the highly pathogenic avian flu A H5N1 continues to crop up in dairy and poultry workers but doesn't seem to represent a broad risk to others, with no known human-to-human transmission. I neglected to mention last week some preliminary results from the seroprevalence study in Michigan dairy workers: none of 35 tested workers had antibody to the virus, suggesting that asymptomatic infections aren't common. However, we need a sample size larger than 35 to get a better handle on this.

Last week's MMWR contained a report supporting the impression that this particular avian flu strain in humans is a very mild disease.

Wash Your Parsley

Did you know that the FDA performs regular microbiologic surveillance sampling of foods? Last week they reported results from sampling of basil, parsley, and cilantro, 3 of my favorite herbs. Below are numbers for the prevalence of various pathogens in different herbs; 95% CI are in parentheses.

Herb	Cyclospora cayatenensis	Salmonella spp	Escherichia coli
Cilantro	9.2% (4.4-16.5)	2.8% (1.1-5.7)	0% (0-1.5)
Parsley	1.3% (0.5-2.6)	0.9 (0.4-1.8)	0.1% (0.4-1.8)
Basil	0% (0-2.6)	0.7 (0.1-2.7)	0.7% (0-1.4)

For comparison, grocery store Salmonella spp. contamination rates for chicken vary from about 8 to 24%, depending on the study.

Want Some Listeria With Your Liverwurst?

CDC has been investigating a Listeria outbreak linked to deli counter sliced foods, and now one brand of liverwurst tested positive for Listeria. It's possible that a single product could have contaminated slicing devices, causing Listeria to end up in other deli foods. I hope your favorite deli counter practices good cleansing practices for their slicing machines. If not, you might get a side of Listeria with other deli products too.

Ever Heard of Oropouche?

Probably not, unless you are an infectious disease nerd or familiar with the island of Trinidad or the Amazon basin. Oropouche virus (OROV) is still known by the old practice of using a geographic term to name it Now we have new attention focused on this virus, previously thought to cause a relatively harmless though uncomfortable febrile illness. It was first discovered on Trinidad in 1955, in a forest worker from Vega de Oropouche, Trinidad. OROV is endemic to the Amazon basin, and Brazil is seeing a big upsurge in Oropouche fever this year.

With that have come some troubling new reports. OROV is an arbovirus related to dengue, and it mostly causes an acute febrile illness with sometimes very painful myalgias, similar to dengue, zika, chikungunya, malaria, and similar infections. It is transmitted primarily by Culicoides paraensis, a biting midge, but also can be transmitted by other biting insects including Culex mosquitoes.

Last week the Brazilian health ministry confirmed 2 deaths from Oropouche fever, both in healthy young women. The clinical descriptions resemble dengue hemorrhagic fever. Also, the Pan American Health Organization is investigating possible vertical transmission of the virus from 2 infected mothers. One pregnancy resulted in miscarriage, the other with intrauterine fetal death. PAHO has issued guidelines for evaluating possible vertical transmission of OROV. These studies should help us understand if OROV is similar to Zika virus's ability to cause fetal malformations and other severe outcomes. [Note that you may need to activate Google Translate to read these links.]

Meanwhile, I haven't seen any C. paraensis around my house.even though they do range into the northern US, including Maryland. They are pretty tiny, can be less than a millimeter, so good chance I would miss them. I'm somewhat curious to know if I'm also a midge magnet, but really I'd rather not find out.

Summer Surge is Coming

Bud WiedermannJuly 21, 2024July 21, 2024Leave a comment

If past experience with wastewater monitoring is worth anything, we will see a surge in covid illnesses starting in the next few weeks. And, that may not be the only summer surge in the works.

Wastewater

CDC wastewater data for SARS-CoV-2 is very reminiscent of the last 2 summers when we saw subsequent upticks in covid illness.

Of course this can vary across the country and is less informative due to absence of wastewater tracking in large swatches of the country. Still, you can see that higher levels of activity (the darker the blue the more the virus concentrations, with gray denoting insufficient data) are common all over. (Data as of July 18, 2024.)

Contrast this with the latest map of influenza-like illness that should pick up covid cases - nothing much doing here.

Wastewater tracking methodology is the least changed post-pandemic, so it is the most useful information to use to compare with past years. Monitoring of infections, illnesses, hospitalizations, and deaths have all changed dramatically, due both to changes in individual behaviors in testing use and changes in reporting mandates for communities and medical institutions, with resulting under-reporting of clinical events due to covid. Keep an eye on what happens on the west coast, probably the first region to ring in the clinical surge.

Take-away point: it might be time for high-risk individuals to go back to masking and avoidance of high-density indoor crowds for a while. New covid vaccines may be available as early as next month.

Speaking of Influenza

Not surprisingly, more human cases of influenza A H5N1 have cropped up in Colorado, this time in poultry workers involved in culling infected chickens. Clinical illness is mild. CDC has sent an outbreak investigation team to these sites and, coupled with a serologic survey getting going in Michigan, should help define modes of transmission and range of clinical illness.

PEP Didn't Work for Covid

A new article in NEJM failed to show any benefit of nirmatrelvir-ritonavir (Paxlovid) compared to placebo in postexposure prophylaxis for household contacts of persons with covid infection.

It's a well-constructed study and should end talk about using this agent for post-exposure prophylaxis in most circumstances.

Fear of Flying

No, not the Erica Jong book. I came across a systematic review published recently suggesting that masking was beneficial on long airline flights. It covered studies performed in the early pandemic period so it may not be entirely reflective of current events, but it was interesting.

It's not overwhelming evidence, but wearing a mask on long airline flights might be a choice, both for high-risk individuals as well as for those who just don't want their expensive vacations spoiled.

Enterovirus Surge?

July through October usually is peak enterovirus season in the US, with much variability depending on climate and who knows what else. You may not be aware, but CDC has a National Enterovirus Surveillance System (NESS) set up to monitor enteroviral activity. It is a laboratory based system, and reporting is passive and voluntary, so it tends to have relatively little data and a significant lag in reporting spikes in enterovirus illness. 2023 data, as of April 2024, reported on 193 specimens tested at CDC for that entire year. It is mostly useful for identifying strains responsible for more severe illnesses such as acute flaccid myelitis.

Anecdotally though, it seems as if we're having one of those bumper years for enteroviral disease. In my telemedicine practice at a few regional hospitals surrounding Washington, DC, I've had a handful of newborns with mostly mild illness test positive. Similarly, I'm hearing a lot about hand, foot, and mouth disease from primary care doctors consulting me as part of some nationwide volunteer curbside consults I perform.

If this is true, primary care offices, urgent care settings, and emergency departments could get a little busy with covid and enterovirus illnesses soon.

Tag: COVID-19