West Nile Virus

Seeing You in September

Bud WiedermannSeptember 1, 2024September 2, 2024Leave a comment

This month always bring me back to The Happenings version of "See You in September;" I remember it fondly from my junior high school era. The Harvest Month often is a transition period from summer to fall/winter infections.

The Respiratory Infection Front

Right on schedule, the ACIP published its official flu vaccine recommendations. Nothing new in there, but it's a good one-stop shopping place for seasonal flu information. Things remain calm on the overall respiratory illness view, and covid may have reached its peak.

However, I'm still waiting for covid wastewater trends to start heading down in most areas of the country (same link as above). We may not be out of the woods yet.

Also note that the covid vaccine from Novavax was authorized by FDA this week. I'll be interested to see how effectiveness compares to that of the mRNA vaccines; Novavax targets a slightly earlier variant (JN.1) than the Pfizer and Moderna products which used KP.2. KP.2 is decreasing in prevalence in the US but still is more closely related to the current variants KP.3.1.1, KP.2.3, KP.3, and LB.1.

We have more longterm follow-up information about myocarditis and covid, looking at both vaccine- and natural infection-associated complications compared to other ("conventional") etiologies. It looked specifically at individuals 12-49 years of age hospitalized with myocarditis. Without going into great detail, it was clear that vaccine-associated complications were less common than with myocarditis associated with conventional or SARS-CoV-2 infection; however, confidence intervals were wide for several of the outcomes due to low numbers of events.

I was excited to see a new update from the HIVE (Household Influenza Vaccine Evaluation) program that has been monitoring households in Michigan since 2010 and was expanded to cover other respiratory infections in later years. The new update covers the years 2015-2022. (The watermark in the figures below signifies this is an accepted manuscript that hasn't yet appeared in the print journal.) Even though it's limited to southeast Michigan, it is valuable data because it is an ongoing active surveillance program in these volunteer households and gives us a glimpse of how the pandemic affected other virus epidemiology.

Far Away Challenges

Mpox continues to rage in the DRC and other areas of Africa, with exported cases appearing in far-flung countries. In addition to vaccine, these countries need better front line diagnostic tests. WHO has requested test manufacturers to apply for emergency approval.

On the polio front in Gaza, we've all heard the good news that there will be a pause in fighting to allow for vaccine administration, but it remains to be seen if this will really happen. Regardless, this will be an extremely difficult undertaking, targeting over 600,000 unprotected children in the region.

Bugs Transmitting Bugs

Healthcare providers and the general public are understandably reeling from all the information about various outbreaks of vector-borne infections. It's important to keep in mind 2 main points: 1) Nothing is happening this year that hasn't happened before in the US. This is the season for vector-borne viral infections. 2) Global warming has increased both the range of these vectors, introducing these infections to areas that haven't seen them in past years, and also increased the season length that these infections circulate. We could see increases in all these infections in coming years.

Here's a breakdown of some of the viruses being hyped in the news.

West Nile Virus

Approximately 70-80% of infections are asymptomatic. The most feared complication, neuroinvasive disease, occurs in <1% of all infections but has a 10% mortality and higher rates of permanent neurologic sequelae such as paralysis. So far in 2024, we have had 289 cases from 33 states in the US, with 195 being neuroinvasive (reflecting the fact that only the worst cases get tested for WNV, not any change in asymptomatic rates). Here are some maps for prior years in the US:

As of now, nothing out of the ordinary for West Nile disease in the US. But, it's pretty common if you recognize that we're only identifying maybe 1% of infections.

Dengue

Here the risk is very high in Puerto Rico, but otherwise mostly restricted to travelers from the current epidemic/endemic areas. Some border states, especially Florida, are more likely to see autochthonous (locally acquired) cases. The asymptomatic infection rate is about 75%; 5% of the symptomatic infections progress to severe dengue with capillary leak syndrome and/or hemorrhagic complications. IMPORTANT CLINICAL PEARL: severe dengue usually appears when things otherwise look good - start of afebrile phase after 2-7 days of the febrile phase. This is the time to be very vigilant if dengue is suspected. The slide below (#42 in the pdf) is taken from a wonderful IDSA/CDC Clinician Call webinar this past week, available at https://www.idsociety.org/globalassets/idsa/multimedia/clinician-call-slides--qa/8-28-2024-clinician-call.pdf and https://www.idsociety.org/multimedia/clinician-calls/cdcidsa-clinician-call-update-on-dengue--other-vector-borne-diseases/.

Here are some numbers from the main CDC website above.

For 2024, the only locally acquired cases in the US have been in Puerto Rico (2676 cases), US Virgin Islands (85), and Florida (21), though those numbers are certain to rise since the season isn't over and reporting in general is delayed. If you add in the travel-associated cases, we've seen a little over 4000 in the US.

Oropouche Virus

This is a relatively mild illness for the most part. The asymptomatic infection rate is around 40%, but 4% of those with symptoms will develop neuroinvasive disease. Now there is concern for vertical transmission in pregnant people, still not completely clear. Management guidelines for infants with possible intrauterine infection are updated and available.

Although I was aware of Oropouche virus previously, this is the first year I've ever heard of the term "sloth fever" which only applies if you acquire the infection in the jungle. This is a slide from that same IDSA/CDC webinar, slide 69 in the pdf.

Oropouche may be over with in South America now, and the main risk area remaining is Cuba. CDC reported 21 US cases in travelers returning from Cuba.

Eastern Equine Encephalitis

Saving the worst for last. It's very uncommon, but you definitely don't want EEE. The encephalitis picture occurs in <5% of those infected with EEE virus, but of those with encephalitis the mortality rate is 30%, and 50% of survivors have permanent sequelae.

We've had 4 cases in 2024 so far. Here's data from prior years:

This is a horrible disease. Certainly precautions such as mosquito spraying and personal protection from bites should be implemented in areas where the virus has been identified.

Earworms

Not wanting to end on a depressing note from the rare but severe EEE disease, I thought of earworms. I'm not referring to the real earworm infecting corn ears, nor RFK Jr.'s brain worm, but rather the more contemporary use of the term. Last week I went down the rabbit hole for the Maurice Williams song "Stay," and this entire past week I've been unable to get it out of my head. Maybe I'll replace it with "See You in September."

One More Time This Summer

Bud WiedermannAugust 25, 2024August 25, 2024Leave a comment

Summer is supposed to be the slowest season in my line of work, but it doesn't seem like it. I've had trouble keeping up with everything, including some old news that I just found out about today. Maurice Williams died on August 5. If that name doesn't ring a bell, stay tuned. Here's what's up for this last post of the summer.

Mpox

It looks like we can add Gabon to the list of countries with exported mpox, this in a 30-year-old man who had stayed in Uganda for 2 weeks. The notice doesn't state whether or not this is clade I, but given that it appears to have been acquired in Uganda there is a good chance that it is. The latest WHO news was posted on August 22, the same day we heard from the CDC about the US response.

By no means is this the next pandemic, but we are seeing global spread of the clade I strain via travelers. Most important is ensuring affected African countries receive adequate vaccine supplies soon. In the US, persons in high risk groups also should be vaccinated.

Measles Check-In

Oregon is the latest state in the measles outbreak spotlight. Nationally the cases are percolating along at a steady rate.

In my post last July 28, I was halfway kidding about waiting for symptoms of West Nile virus after all my mosquito bites. West Nile is in "full swing" in Europe currently. Now I see in today's Washington Post that Tony Fauci is back home after a 6-day hospitalization for West Nile infection. Although he is 83 years of age, that's a long hospitalization and I hope he didn't have serious neurologic or other complications. I wish him a speedy recovery.

A little trivia piece I discovered years ago, did you know West Nile virus was tried as a cancer treatment in the early 1950's? Research on using flaviviruses as oncolytic agents continues. Unfortunately the lead investigator of that 50's study is mostly remembered for a serious ethical breach, injecting tumor cells into prisoners to study tumor immunology.

Timing is Everything

I have a complicated plan for how I'm going to time when I get my flu and covid vaccines in the coming weeks, based on travel plans and guessing about peak flu season. At my age, waning immunity following vaccination could be clinically significant.

This brings me to an interesting study in the BMJ trying to define optimal timing for influenza vaccination in young children. It utilized data from an administrative database in the US for timing of vaccination of over 800,000 children ages 2-5 years during several flu seasons. Bottom line, it looked like October was optimal. I wouldn't necessarily alter plans based on this study; every flu season has slightly different timing. It's probably a better plan to just vaccinate when you can, whether it be at regular checkups or flu vaccine events on evenings and weekends.

Holding My Breath on Polio

I'm still hoping polio doesn't break loose in Gaza, but I'd be more hopeful if vaccine could be distributed there. WHO has full plans in place to distribute the relatively new novel oral polio vaccine type 2 (nOPV2) to about 640,000 children under 10 years of age in 2 campaigns separated by a month. Wastewater monitoring suggests this is the strain that caused the case recently detected in a child in Gaza; we're still waiting for confirmation from a regional lab in Lebanon. Now we just need an effective ceasefire to allow this and other humanitarian aid to be implemented.

Covid

The big news was the not surprising FDA approval and emergency use authorization of the KP.2-based mRNA vaccines from Pfizer and Moderna. Novavax approval is still pending due to a longer manufacturing process. As I've said many times, if one looks at the level of individuals, it's pretty clear that vaccination benefits outweigh risks for every age group. New interim recommendations are available from the CDC.

Here's a quick look at a few disease activity indicators over the past year:

Wastewater hasn't changed much nationally.

Regionally, only the Northeast seems to be rising, though still lower than most other regions.

We'll see what happens with covid (and measles) now that schools are starting back again.

In the midst of all this, we have a new study on long covid in children. It was a multicenter prospective cohort study of about 900 younger children and 4500 adolescents, most with covid infection but some not infected who served as controls. The report is loaded with data and complexities; I'm sure everyone in the field is looking it over closely.

It's tough to summarize the findings succinctly, but perhaps you can enlarge the figure below to see details. The darker color shades are the more prominent symptoms in each cluster. Clustering of types of symptoms varied between adolescents (12-17 years) and school-age children (6-11 years). I'm very happy to see this type of analysis; it is possible that different clusters have different pathogenetic mechanisms suggesting different treatment approaches. Clusters in the younger children were in the neurocognitive, pain, and GI domains, whereas loss of smell or taste, pain, and fatigue/malaise were highlighted for the adolescents.

This study won't change clinical practice immediately, but it is a major step forward in providing a framework to base treatment studies.

"No Good Songs Ever Came Out of the 1950s"

That probably inaccurate quote, heard when I switched my car's Sirius/XM to the 50's station, came from a musically-inclined and knowledgeable friend of mine. I'm pretty sure he uttered it just to get a rise out of me, which it did. IMHO, the 50's produced a lot of good songs and shouldn't be remembered just for some wacky West Nile virus studies.

The title of this week's post is a nod to Maurice Williams who wrote the song "Stay" in my birth year, 1953, but then put it on the shelf until he recorded it with the Zodiacs in 1959. It came out in 1960 and was a big hit at just 90 seconds in length. You may be more familiar with it from the 1977 cover with slightly altered lyrics by Jackson Browne, Rosemary Butler, and David Lindley (and the 9-minute mini-medley with "The Load Out") or from the 1987 movie "Dirty Dancing" that used the Williams original. Regardless of which of the couple dozen versions I listen to, this is one of those songs that always brings a smile to my face.

Dog Days of Summer

Bud WiedermannJuly 16, 2023July 16, 2023Leave a comment

I've just returned from a wonderful family week at the beach to a steaming suburban DC and an annoying surprise at home. I'll just bask in my vacation afterglow and belatedly compose this post.

Bugs cont'd

I didn't think it was possible, but there are more mosquitos around my house now than before I left for vacation. Right on schedule, West Nile Virus infections are starting to heat up.

Hot off the presses, you can also add Texas to the list. Remember that although West Nile Virus is feared for its neurologic manifestations, most infections are either asymptomatic or result in a nonspecific febrile illness. The neurologic cases are the tip of the iceberg.

Hepatitis C - We're Missing the Mark in Public Awareness

A recent publication noted a big gap in delivery of care for hepatitis C, summarized below. I really like their cool poster-type depiction, check out the bottom line (at the bottom, of course).

Once again, our wonderful technologic advances in medicine are clouded by a failure to have them reach those who need them most.

More on Neonatal ECHOvirus Infections

The World Health Organization reported more cases of neonatal ECHO-11 infections in newborns, originally in France as discussed in these pages on June 4. Now WHO reports new cases from Croatia, Italy, Spain, Sweden, and the UK. No evidence so far that these events in different countries are connected; this might just reflect enhanced surveillance given the initial alert from France. The link above has a nice discussion of various aspects of the cases. Again, keep severe enteroviral disease in mind with any sick newborn in whom bacterial etiologies are not revealing.

'Demic Doldrums

Remember wastewater monitoring? It's not the greatest tool in the US due to the fact that monitoring is voluntary and leaves much of the US with no data. However, an epidemiologist at Johns Hopkins has been blogging on this and is predicting we are about to see an uptick in southern states. She admits the data are iffy, we'll know eventually if she is full of hot air or not.

Some interesting data appeared regarding maternal covid vaccination and newborn antibody levels. This was a small but well-studied group of 76 mothers who received an mRNA vaccine during pregnancy. Higher maternal antibody levels were seen in mothers who had systemic symptoms following the second vaccine dose, though all had good responses. Maternal transfer of IgG to infants was highest in those vaccinated in the second trimester. Breast milk IgG and IgA antibody to SARS-CoV-2 persisted about 5-6 months, just in time for the infants to start their own vaccine series! There were no significant adverse events in mothers or infants. Bottom line: since we don't know what covid will do in the future, pregnant persons would be well advised to get that new vaccine dose during their second trimester.

The US Government Accounting Office published some further recommendations for pandemic preparedness. I'm very glad these are appearing, but public interest and funding have cooled dramatically.

Also, I was pleased to see an analysis of journalistic coverage of preprint publication before and during the pandemic appearing (where else) but on the well-known preprint site BioRxiv. This coverage hit the boiling point during the pandemic but applied only to covid preprints, not to other scientific reports. Next up I hope we see some analysis of how many of those preprints never appeared in a peer-reviewed publication; some have attempted chart this already, but we probably need to wait another 2-3 years before passing judgement. I continue to worry that too much attention was focused on preprint postings during the pandemic; the blame for this is shared by journalists, scientists, and the universities and other organizations where the work was performed.

Lest we forget about flu, things aren't too bad worldwide but WHO did report some close-to-home hot spots in Costa Rica, Honduras, Nicaragua, and Panama.

My Astrologic Education

I always assumed the saying "dog days of summer" had something to do with a panting dog in the heat. I was barking up the wrong tree; now I've found out it originated with Hellinistic astrology. Officially, the dog days run from July 3 to August 11, according to the Farmer's Almanac.

I had a great time with my 3 sons and families at the beach, enough to keep me somewhat cool and calm after the thunderbolt of finding my air conditioner on the fritz when I returned home. Fortunately for my dog days, my house has 2 air conditioners. Until now, this was a complete mistake - our house could be handled by just one unit if only the ducts were all linked together. So, for now half the house is tolerable and I won't complain too much, at least until I get the bill from the air conditioning service.

Oh, and in case you haven't noticed, I've sprinkled weather- and temperature-related references and puns throughout this week's post. To keep your mind from sweating, see if you can find all of them. Answers in next week's post.

Tag: West Nile Virus