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Jonathan Ryder, MD

Jan 1 • 9 tweets • 5 min read

A clinical pearl I learned during a recent stent on clinical service is the relationship between influenza & group A streptococcus (GAS, AKA Strep pyogenes).

Thus, let's commence an #IDTwitter #Tweetorial

/thread

1/ CDC & WHO are reporting increases in GAS in children this winter

I suspect this is due in part to GAS's association with viral respiratory illnesses, in particular flu, but this association isn't exclusive to children or flu

emergency.cdc.gov/han/2022/han00…

who.int/emergencies/di…

2/ Influenza mediates an increased risk in bacterial infection through multiple mechanisms
- ⬆️ bacterial adherence by removing sialic acid
- Mucociliary escalator destruction
- ⬇️ macrophage clearance

ncbi.nlm.nih.gov/pmc/articles/P…

3/ Murine models suggest
1) Risk of GAS superinfection depends on the flu & GAS strain types
2) Flu ⬆️ GAS adherence & internalization due to ⬆️ fibronectin & fibrinogen ligands
3) Influenza vaccination protects from GAS mortality

ncbi.nlm.nih.gov/pmc/articles/P…

4/ In a paper from Morens & Fauci (yes, that one) in 2007 regarding the 1918 H1N1 influenza pandemic, Strep pneumo & GAS were the most commonly identified bacteria in autopsy studies (followed by H. flu & Staph aureus)

academic.oup.com/jid/article/19…

@CDCMMWR

5/ Similarly, a @CDCMMWR study of 77 autopsies from the 2009 H1N1 influenza pandemic found that among 22 patients with identified bacterial pathogens, 6/22 (27%) were due to GAS (only Strep pneumo & Staph aureus were more common)

cdc.gov/mmwr/preview/m…

6/ Likewise, Israel saw an increase in GAS bloodstream infections during the 2009-2010 influenza season

academic.oup.com/cid/article/53…

7/ Interestingly, influenza vaccination in Army recruits in 2002-2006 was associated with a 66% decreased risk of GAS infections

pubmed.ncbi.nlm.nih.gov/18501484/

8/ A few key takeaways on flu & GAS:
💥 Influenza and invasive GAS infections have a close relationship
💥 Consider GAS in DDx of bacterial superinfection with influenza (next to Strep pneumo and Staph aureus)
💥 Preventing flu via vaccination likely protects against GAS too!

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More from @JonathanRyderMD

Jonathan Ryder, MD

@JonathanRyderMD

Jun 5, 2022

@DrDidwania_ID

1/
TIL about BORSA/MODSA, so cue the #IDTwitter #Tweetorial.

Thanks to the many contributors on @DrDidwania_ID's post on a very interesting variation of Staph aureus that phenotypically matches MRSA, but does not carry the correct genotype.

/thread

https://twitter.com/DrDidwania_ID/status/1532900924276060160?s=20&t=TeetlhAUSb230Iwbp3zDsg

2/
Methicillin resistance is usually conferred by an altered penicillin-binding protein (PBP2a) via the gene mecA (or sometimes mecC).

MecA is detected by current molecular testing as a marker of methicillin-resistance for Staphylococcal species

link.springer.com/chapter/10.100…

3/
What is BORSA & MODSA?

BORSA: borderline oxacillin-resistant Staph aureus
MODSA: modified Staph aureus

Just add this to MSSA, MRSA, VISA, and VRSA in the genre of Staph aureus-related acronyms!!

Key article I referenced for this thread: pubmed.ncbi.nlm.nih.gov/28893360/

Read 12 tweets

Jonathan Ryder, MD

@JonathanRyderMD

Jan 28, 2022

@CDCMMWR

New ACIP recommendations for PCV15 and PCV20 today in @CDCMMWR!

So what do we do for patients who have already received PCV13 or PPSV23?! What combo do we give patients now?

/thread

cdc.gov/mmwr/volumes/7…

Both PCV15 and PCV20 were FDA approved in 2021.

Both use a capsular polysaccharide antigen conjugated to a protein carrier as their mechanism (like PCV13).

jamanetwork.com/journals/jama/…

Both PCV15 & PCV20 have the same serotypes as PCV13 + more

PCV20 has all the same as PCV15 + 5 more

PCV20 shares 19 of the same serotypes as PPSV23 with 1 unique to PCV20 and 4 unique to PPSV23.

Read 6 tweets

Jonathan Ryder, MD

@JonathanRyderMD

Jun 28, 2021

@UNMC_ID

1/ Wow, finishing up my last rotation as a 1st year ID fellow on gen ID has been a whirlwind @UNMC_ID! Had an all-star group of faculty (@Cortes_Penfield, @fadul_nada & @DrJRMarcelin) and an amazing group of residents, students & pharmacists! Time to review a month of learning:

2/ Let's start with an unusual one:
Syphilis can be inoculated via tattoos or manifest with a rash within the tattoo in secondary syphilis. This localization is thought to be due to decreased immune response within the tattoo.
pubmed.ncbi.nlm.nih.gov/30363028/
ijam-web.org/article.asp?is…

3/ Erythema multiforme has classic target lesions and can cause mucus membrane involvement. Classic triggers are HSV & Mycoplasma pneumoniae. Adenovirus is also associated, especially with ocular & genital involvement.
sciencedirect.com/science/articl…
medicaljournals.se/acta/content/h…

Read 15 tweets

Jonathan Ryder, MD

@JonathanRyderMD

Mar 8, 2021

@UNMC_ID

1/ Haven't done this in awhile, but want to share some great literature we discussed this week while on the @UNMC_ID general ID service! So happy to have a big multidisciplinary team led by @DrJRMarcelin along with our pharmacists @Molly_M_Miller & @bergmanscott!

2/ Will start with my favorite article on carbapenem-resistant gram-negative infections from Doi et al with my own adaptation of their super useful table

academic.oup.com/cid/article/69…

@UNMC_ID

3/ We continue to #RespectTheStaph learning of an unusual manifestation of Staph aureus prostatic abscess from a future @UNMC_ID fellow's paper & another lit review.
academic.oup.com/ofid/article/6…
ncbi.nlm.nih.gov/pmc/articles/P…

Read 8 tweets

Jonathan Ryder, MD

@JonathanRyderMD

Aug 23, 2020

@UNMC_ID

My 3rd week of general ID @UNMC_ID has come to a close with #PasteurellasFellas, led by the wonderful @KellyCawcuttMD! Really appreciate her critical care insight on ID. We had some fascinating discussions this week. Time for another recap! #IDTwitter #IDPearls

@bergmanscott

A fundamental question this week was TB or not TB (sorry, not sorry for the pun @bergmanscott)

ncbi.nlm.nih.gov/pmc/articles/P…

We discussed the differential diagnosis of miliary nodules on imaging. TB leads the list, but dimorphic fungi (histo, blasto, cocci) can be just as common in endemic areas. Malignancy as well.

atsjournals.org/doi/pdf/10.151…
ncbi.nlm.nih.gov/pmc/articles/P…

Read 13 tweets

Jonathan Ryder, MD

@JonathanRyderMD

May 24, 2020

1/ While on my current GI rotation, I've been reading about Clostridioides difficile because, you know, #IDNerd. I ran across something I had not learned about before:

A Hypervirulent Strain of CDiff!

So naturally, I had to look into this.

/thread #Tweetorial #CDiff #IDTwitter

2/
What is the name of the strain of hypervirulent CDiff?

3/
The hypervirulent strain of CDiff is known as NAP1/B1/027, which stands for North American pulsed-field gel electrophoresis type 1, restriction endonuclease analysis type B1, PCR ribotype O27.

That's a mouthful.

So what's the big deal about this strain?