July 2021 – Pediatric Infection Connection

Something to Distract You From the Bad Variant News

Bud WiedermannJuly 25, 2021Leave a comment

Things aren't looking great around the country, much less the world, as the delta variant shows just how effective it is at spreading including among vaccinated individuals. Here's a couple pieces of news to cheer you up.

School Bus Transmission May Not Be All That Terrible When Done Correctly

An observational study published online in the Journal of School Health suggests that spread of SARS-CoV-2 on school buses isn't that high. Investigators reviewed existing data from 15 school buses in Virginia between August 24, 2020 and March 19, 2021 when they were operating at near capacity. In general there were 2 students per seat, universal masking, simple ventilation strategies, and regular pooled saliva testing of everyone with confirmation of positives by a PCR nasal swab. They found 39 students who were positive but no apparent transmission on the buses themselves.

Of course this study has limitations, including the retrospective observational design that didn't allow confirmation of a lot of details, the small sample size, and perhaps most importantly the fact that this was all before the delta variant became dominant. Still, it does offer some reassurance regarding transmission on school buses.

GBS and the Janssen Vaccine

You might expect me to file the association of Guillain-Barre syndrome and the Janssen (Johnson & Johnson) vaccine as bad news, but the fact that it is still really rare is actually a good thing. The ACIP met on July 22 to discuss the situation; you can access the key slide deck online. With 12.6 million doses of the vaccine administered through the end of June, 98 cases of GBS have been reported. The highest risk group was men 50-64 years of age at 15.6 per million vaccine doses, still far below the risks associated with infection itself.

We now know of rare side effects with the 2 mRNA vaccines (myopericarditis) and with the Janssen vaccine (TTS (thrombosis with thrombocytopenia syndrome) and GBS). Still, these side effects are so rare that the benefits of vaccination clearly outweigh risks of serious complications from COVID-19 disease. Immunization is still the best choice for everyone.

History Repeats Itself 2

Bud WiedermannJuly 18, 20212 Comments

The "Pandemic of the Unvaccinated"

Dr. Walensky's sound bite this past week quickly became the standard catch phrase in the media, and it isn't misleading. Our current COVID-19 infection rate is in the same (but slightly lower) ballpark as last summer, but what isn't in the same ballpark are numbers of hospitalizations, ICU admissions, and deaths, at least not yet. The main difference between this summer and last is the target population: now we are seeing the pandemic being driven by younger (unvaccinated) individuals who are less at risk for the more severe outcomes of COVID-19 infections. Clearly vaccines work, and we now have real-world evidence that demonstrates this. We are still in a race between variants and reaching herd immunity, and each one of those newly-infected individuals might be the one to develop and spread a more troublesome variant that not only has increased infectivity but also increased severity and/or ability to evade vaccine protection.

As a slight aside, yesterday (July 17) I tuned into a regular CDC/IDSA COVID-19 Clinician Call, and this one I thought was particularly useful with explanation of immunity from natural infection versus vaccines and a summary of COVID-19 antibody testing. The key take-home for antibody testing is that it should not be used to infer immunity following vaccination. These tests were only designed to predict likelihood that an individual was previously infected and says nothing about degree of protection. Just say no if a patient requests an antibody test to determine if they are immune. The recording from the July 17 session should be available within a few days.

Ready for Monkey Pox?

Also in the category of history repeating itself, we learned this past week about an individual with monkey pox in Texas, likely picked up in Nigeria. We see sporadic cases of monkey pox in the US, it isn't unexpected. Do you know what to look for to spot a case?

First of all, in spite of the name, don't ask about monkey exposure. Most humans acquire monkey pox from other animal reservoirs, principally rodents, in endemic areas. These areas include Central and West Africa. It can be a difficult diagnosis before the rash appears; the prodrome is nonspecific and consists of fever, malaise, headache, and myalgias. After the 1-3 day prodrome, the rash appears initially as macules and then progresses to papules, vesicles, and pustules. It is very similar to smallpox in that lesions tend to distribute more peripherally. Transmission from infected individuals to other humans most commonly is via droplet spread and likely requires prolonged close contact. Skin lesions themselves also are contagious. Travel history is the key, be sure to ask about that for anyone with a nonspecific febrile illness. Incubation period is about 5-13 days, easily long enough to allow for international travel before symptoms begin.

Of Vacations and Variants

Bud WiedermannJuly 11, 2021Leave a comment

Is Your Vacation Spot an Immunization Wasteland?

Overwhelming evidence suggests that immunization is a highly effective preventive tool for COVID-19 disease, With the delta variant now the leading strain circulating in the US, risk of infection is now higher than with previous strains and those immunized are somewhat less well protected. Thankfully, complete immunization does still protect well against serious disease; partial (single dose) immunization with either of the mRNA vaccines is not so great protection.

Much of the DC metropolitan area (the DMV) enjoys a high immunization rate, though some zip codes or wards have extremely low rates. But how about traveling beyond the DMV for summer vacation? I recently found a nice web site, US COVID-19 Vaccination Tracking, originating from Georgetown University. You can check out their interactive map to see if your dream vacation site is full of unvaccinated local residents, though only down to county-level detail. I'm not suggesting you change your vacation plans based on this, but at least you'll have some idea how much to worry when you go to the local grocery store.

Prior SARS-CoV-2 Infection Doesn't Give You a Pass on Immunization

This fact has been apparent for a few weeks now, though only from relatively difficult-to-decipher non-peer-reviewed sources. Now we have a peer-reviewed article in Nature with more easily accessible data. This dilemma is all thanks to the delta variant. If you happen to run across anyone declaring they don't need a vaccine because they already had COVID-19 infection, plus set them straight and encourage them to be immunized.

And Now for Something Completely Different…

Bud WiedermannJuly 4, 2021Leave a comment

RSV on the Upswing?

I always keep a close watch on respiratory pathogen panel results at Children's National. It is not in any way a formal active surveillance program but does help monitor what viruses are out there. If you are in front-line practice you probably already know that the "routine" respiratory pathogens are back in circulation. Recently our most prominent virus group has been parainfluenzavirus, particularly type 3. Paraflu commonly has some seasonality with peaks in spring and fall. However, I've also been watching the Respiratory Syncytial Virus numbers. RSV is of course primarily a winter pathogen, but a few pockets around the country have been reporting very high numbers of RSV cases. At CNH we haven't quite seen those numbers but still the positive detections are higher than usual this time of year, about 3-6 children per week. Also, we have had a few kids in intensive care with more severe RSV disease. It isn't time to bring out the palivizumab early but certainly bears watching.

Swine Fever Viruses

African Swine Fever and, just recently, Classical Swine Fever, have reared their ugly heads but mostly have been overshadowed by the SARS-CoV-2 pandemic. ASF, a large DNA virus, and CSF, a small RNA virus, don't infect humans. So, why should we care?

Both viruses are devastating to swine, which in turn affects the swine industry and therefore those dependent on that industry. A breakout of ASF in Europe, Asia, and elsewhere around the globe has been responsible for rises in pork prices world-wide. ASF hasn't circulated in North America, but it could be imported very easily by travelers returning from these areas with prohibited food and other products.

CSF really has been absent from Australia, North America, and Europe but is endemic in other parts of the world. Bhutan just announced an outbreak in wild boars beginning June 23.

As stated above neither ASF nor CSF infects humans, and there is no known risk to ingesting pork infected with these viruses. (Of course, plenty of other reasons to eat only well-cooked pork!) Transmission is just among pigs/boars; ticks (a soft tick, Ornithodoros sp.) can transmit ASF to swine. Expect more price increases for pork relative to the general increases in consumer goods related to the pandemic. In May 2021 pork prices were $109.58/lb, compared to $62.78/lb a year ago. Culling infected herds is the main method to control domestic pig spread although a CSF vaccine does exist as well. I hope these measures will be effective in reigning in these pathogens before more economies are devastated.

Month: July 2021