July 2024 – Pediatric Infection Connection

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.

The World We Live In

Bud WiedermannJuly 14, 2024July 14, 2024Leave a comment

The shootings in Pennsylvania give all of us a chance to reflect. We should be thankful that more people weren't harmed while also keeping the families of the critically injured and the dead close to heart.

More Poultry Workers Presumptively Infected With Bird Flu

The Colorado state health department now reports 3 other presumptive H5N1 cases in poultry workers, adding to the single case in that state earlier this month. All apparently had mild illness with respiratory symptoms and conjunctivitis. We're still waiting for ongoing studies to provide better understanding of transmission modes and extent of infection in high-risk workers; such knowledge likely will lead to effective preventive measures.

Infection in animals is widespread in the US.

Olympic Wastewater

The World Health Organization has plans to monitor 6 pathogens in wastewater from the 2024 Olympics and Paralympics in Paris: poliovirus, influenza A and B viruses, mpox, SARS-CoV-2, and measles. It's an interesting read if you have the time.

More Kudos for Nirsevimab

Last week saw the publication of a report from France of a matched case-control study of nirsevimab effectiveness during the 2023-2024 RSV season and reflects real-world implementation as it occurred in that country. Results were again excellent, 83% (95% CI 73.4-89.2%) effective against hospitalization.

Returning to my broken record mode, I implore all pediatric healthcare providers to ensure families protect their infants with nirsevimab (or with maternal RSV vaccine use).

Blood Culture Bottle Shortage

Usually we worry about medication/vaccine shortages, but don't forget equipment shortages are relatively common. Now the FDA has announced a shortage of blood culture bottles likely to last a long time. This does give me an opportunity to reference again one of my favorite guidelines, recently updated, concerning effective use of the microbiology laboratory.

Many providers were surprised by the recommendations for volume of blood to be drawn for pediatric blood cultures:

Two separate cultures are usually recommended but can be drawn at the same time. Utilizing appropriate skin decontamination and proper blood volumes will increase yield of true pathogens. While one could argue that adhering to the guidelines above would actually increase the number of bottles used (since most pediatric practitioners obtain just 1 culture at a time), I'd push back against that claim by stating that fewer bottles would be used because we wouldn't be obtaining cultures in very low risk clinical settings nor chasing contaminants nearly as often. If you frequently make decisions on obtaining blood cultures, this is a good time to review the guideline section on bloodstream infection.

Remember the Children

I wrote some time ago about how the assassination of President Kennedy in 1963 affected me. I was a 5th grader when the presidential motorcade, including the limousine carrying JFK, the First Lady, and Texas Governor Connally and his wife, drove past my school the day before the assassination. I was one of a couple hundred kids on the curb waving as they went by. I remember the confused thoughts in my 10-year-old mind. Take time to discuss yesterday's event with your children, grandchildren, and with your patients and their families.

I Ain’t Worried*

Bud WiedermannJuly 7, 2024July 7, 2024Leave a comment

H5N1 Human Victim #4

Now we can add a fourth case this year of avian flu in a human residing in the US, again a mild case with conjunctivitis in an individual in close contact with infected dairy cows. No surprise there, but I'm waiting to see what happens with all the summer state fairs that provide more opportunities for human exposure to infected poultry and mammals.

Summer Covid Watching

The bottom line in the US is that covid infections are likely still pretty low, and we don't really know if we'll see a significant surge in the next few months. Any prediction is harder these days because our monitoring systems are probably the worst they've been in the past 4 years. On a national public health level, post-pandemic reporting and tracking have been relaxed and made voluntary, which for many healthcare institutions and jurisdictions can mean no reporting at all. On an individual level, people are less likely to seek testing or treatment, probably due to a combination of numbness from years of being on the edge plus relatively lower disease severity.

I'm focusing on a few data sites.

First is the CDC's Respiratory Virus Weekly Snapshot. The percentage of positive tests sheds some light in disease activity, still cloaked in individual behaviors in seeking testing in the first place and lack of reporting from most home testing. The recent covid percentage is trending up, though not at the level of fall 2022.

Covid wastewater trending is helpful and perhaps the least altered by changes in practice over time. Unfortunately, vast areas of the country have no reporting. Activity levels are rising particularly in the western US, but still well below prior surges. I noted that wastewater updating took a holiday last week, so we're missing the most recent numbers.

Second, I'm keeping a watch on relative predominance of different variants, with an eye to how effective our next vaccines will be. The top 4 variants currently are KP.3, KP.2, LB.1, and KP.1.1. Any late summer or fall surge likely would include one or more of these. I'm waiting for more data on how well serum from recipients of the new vaccines will neutralize these variants in vitro.

Should I Change My Annual NJ Beach Trip?

A flurry of beach closings due to poor water quality last week. I couldn't find any national consortium on this, so you'll need to look at specific states to find out what's going on at your beach rental house this summer. In my browsing I particularly liked the Massachusetts interactive water quality dashboard; Massachusetts seems to be one of the harder-hit states.

Meanwhile, a bit farther south:

Only 1 site in NJ is closed currently, I'm OK!

*

The song I Ain't Worried was written for the beach football scene in the movie Top Gun: Maverick. It was conceived early in the pandemic (when we were worried!) and was an upbeat breather contrasting with the intensity in the rest of the movie. Not a bad antidote for your summer worries, whatever they may be.

Month: July 2024