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@JeffLarnard spoke at @harvardmed joint ID conference today!

"The Old Man and the Sea: Water Associated Necrotizing SSTI"

He had not one, but TWO guests today:
Regina Larocque from @mgh_id
@growingwisdom from @WBUR

Here are few slides: 2/
A quick review of necrotizing soft tissue infection and the LRINEC score
pubmed.ncbi.nlm.nih.gov/29672405/

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Case conference Tuesday -- @vdbpolly did a review of Strep toxic shock syndrome 2/
A recent paper looking at clinda with invasive GAS infection

thelancet.com/journals/lanin…

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@barbramblair​ presented a case today in our combined ICH conference! Final dx is still pending, but here is some of the learning!

@BIDMC_IDFellows @BCHPedsID 2/
Thinking about risk of TB related to TNF-a antagonist therapies. TNFa acts at multiple steps, shown in the graphic below. Also a nice image of the different TNF antagonists

pubmed.ncbi.nlm.nih.gov/20530046/

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A few fun and quick pearls from today's Friday conference: culture neg endocarditis!
#IDTwitter #IDMedEd #MedTwitter @ID_fellows

Q1:
Which of the following is the recommended tx and duration for Coxiella burnetii / Q fever endocarditis? 2/
A1: The answer is Hydroxychloroquine + Doxycycline x 18mo, 24 months if prosthetic valve -- One of the longest ID treatment durations out there!!

Combination therapy is preferred because associated with highest cure rate
pubmed.ncbi.nlm.nih.gov/9927100/

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40F with myelodysplastic syndrome presents with fever, fatigue, and new rash. There are new tender lesions on left arm and right leg, an example below.

Labs: WBC 15, CRP 150

Biopsy is done, what do you expect to find? Poll next!
#IDTwitter #IDMedEd 2/
What do you expect to find on biopsy histopath?

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There was a neuro+ID theme at case conference this week! Case 2 was West Nile meningoencephalitis. Michelle reviewed neuroinvasive WNV infections.

#IDTwitter #IDMedEd #IDFellows @ID_fellows 2/
Potential mechanisms for neuroinvasion:
🚩Direct inf of vasc endothelium
🚩Cytokines disrupt BBB integrity➡️pass thru vasc endothelium
🚩Trojan🐎: infected monocytes trafficked into CNS
🚩Retrograde axonal transport after inf of peripheral neurons

ncbi.nlm.nih.gov/pmc/articles/P…

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55M prev healthy developed gait instability and tremor about 2 months ago. He later starting dropping items due to jerking movements and had word-finding difficulties. Family brought him in due to falls and worsening mood changes.
EEG with periodic sharp wave complexes
MRI 👇 2/
An LP is done ➡️ Which of these studies will be most helpful for diagnosis?

#IDTwitter #MedTwitter #IDMedEd @ID_fellows

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40M p/w abd pain off and on x 1 mo
No nausea, vomiting, diarrhea, fevers

Labs: WBC 14, T-bili 4.0, D-bili 2.8, ALT 220, AST 330, ALP 270

CT abd/pelvis imaging below

#IDTwitter #IDMedEd #IDFellows @ID_fellows

What is on your ddx?! 2/
More images demonstrating multiple smaller cysts in the periphery of the dominant cyst

This distinct appearance gives the dx!

⭐️Cystic echinococcosis⭐️

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25M
- 4d ago HA, myalgias➡️dx’d sinusitis, rx'd Amox
- 2d cough, high fever
- Today CXR: infiltrate on R, small pleural effusion.⬆️LFTs

Landscaper in Marthas Vineyard. No known tick bite. Fevers cont despite change to Ceftriaxone, should we...

#IDTwitter #IDMedEd #IDFellows 2/
Dx: Pneumonic tularemia!
🔸May be a difficult dx. Unlike some forms of tularemia, there are not classic distinguishing features to separate it from CAP/atypicals.
🔸Might see lack of improvement on routine abxs, neg cxs
🔸Inhalation or hematogen spread from other forms (2ary)

1/ 45F p/w months of jaw swelling. Initially 1 nontender nodule, briefly improved after course of abxs-but she has been using makeup bc appeared bluish.

Now jaw feels "lumpy", one area draining, +trismus

Which would help define your suspect dx?
#IDTwitter #IDMedEd @ID_fellows 2/
Cervicofacial swelling (esp jaw) might bring ddx: cancer, TB, NTM, nocardia, and actinomyces.🔵color, brief abx response, sinus tract were clues for Actinomycosis!

Sulfur granules=classic but can be mis-ID'd as nocardia!

Tip:Nocardia+mycobact = acid fast, but actino are not

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85M with CAD s/p CABG and MM on daratumumab/dex
Nausea, vomiting, watery diarrhea 7x per day

Alright #IDFellows, can you ID the organism? Hektoen plate below

#IDTwitter #IDMedEd #MedTwitter @ID_fellows

Photo cred: ASM asmscience.org/content/educat… 2/
Guess Salmonella?
🧫Selective hektoen agar
🧫pH indicator dye:agar🟢➡️🟡 if ferment sugar
🟡NOT Salmonella/Shigella
🧫Na thiosulfate for orgs that produce H2S➡️ferric ammonium citrate+H2S gas ➡️⚫️precipitate
🧫Salmonella=🟢+⚫️center (vs Shigella 🟢only)

https://twitter.com/richdavisphd/status/954458745492271104

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Thanks to Dan Kuritzkes+Suzanne McCluskey for talk on drug resistance today in the HIV core lecture series! @MGHBWHIDFellows #IDFellows @ID_fellows #IDTwitter

To review high yield mutations, check these prior 🧵

NRTI:

https://twitter.com/BIDMC_IDFellows/status/1270812037321502720

NNRTI:

https://twitter.com/BIDMC_IDFellows/status/1271220542532657152

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Additional NNRTI mutations:
🧬E138K🧬
▪️Key rilpivirine resistance mutation
▪️Cross-resistance to ETR

🧬V106I, F227C🧬
▪️Key doravirine resistance mutations

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50M comes to clinic with severe pain on his index finger. It progressed to violaceous lesion with raised borders. PIP/DIP/MCP jts without effusion. No fevers and otherwise feels well.

Works as fisherman on the Cape

What organism?

#IDTwitter #MedTwitter #IDMedEd #FOAMed 2/
👍Correct answer = E.rhusiopathiae, a GP bacillus
🌳Widespread in nature, infecting domestic and marine animals
🦀Infections in humans often from occupational exposure: animal processing, butchers, fisherman, farmers, vets
🔽Break down clinical syndromes into 3 categories:

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A couple (55M/52F) p/w fever 39F, myalgias, dry cough, and mild diarrhea. Pt and his wife love their pet cockatiels (Charlie + Angel). You dx psittacosis!

Pts ask what should happen to their 🦜🦜, what do you say? #MedTwitter #IDTwitter #IDMedEd 2/
Let's learn about psittacosis in humans before we get to the poll answer!

🦠Chlamydia psittaci
🧫Obligate intracellular GN bacteria
🔹22 cases were reported in 2018 to CDC NNDS

🦜Birds are primary zoonotic reservoir (altho has been seen in other animals eg sheep, cattle)

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Case #2 fr Michelle!
75M with prostate ca s/p rad, HTN
4d back pain, confusion per wife
Likes to garden and spend time outdoors
Noted incidentally to have scattered rash on trunks/extremities

Labs:
WBC 15k, H&H 13.3/38.9
Na 128
Cr 0.6
AST/ALT 50s 2/
Dx'd with early disseminated Lyme.
Has evidence of 1st degree AV block on EKG
Has had some mild mental status fluctuations with confusion per wife but otherwise cognitively intact. No meningismus on exam.
Na 128 --> 125

How would you treat? #IDTwitter #MedTwitter #IDMedEd

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A 40F and her 10 yo son present with flushing of neck/face, headache, and diarrhea about 45 min after eating mackerel, rice, and some fruit (mango, cantaloupe).

#IDTwitter #IDMedEd #MedTwitter #FOAMed 2/
What do you think is cause of their sxs? #IDTwitter #IDMedEd #MedTwitter #FOAMed

Pic credits:
bit.ly/39Nvx1O
bit.ly/339lKSj

1/ 55M, h/o psoriatic arthritis on adalimumab, cut hand cleaning🐟after fishing in coastal🌊

~12h later,⬆️finger erythema/edema

Admit: T101, rigors,⬆️HR,⬇️BP

On Ceftriaxone w/o improvement, now finger w/purple hue, blistering. How would you modify abxs?
#IDTwitter #MedTwitter 2/
Did you ID the🦠? Vibrio vulnificus!
🔹GNR
🔹In coastal water, saltwater marsh/wetlands, river estuaries
🔹Peak summer/late fall (water temp⬆️)

Filter feeding shellfish (🦪/clam/mussel/🦀) conc bact more than in water ▶️in virtually all oysters Chesapeake Bay, US gulf coast

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Mini-review of three high yield NNRTI mutations! Continued learning from yesterday.
#IDTwitter #MedTwitter #HIVTwitter 2/
🧬🧬K103N🧬🧬
💠selected by efavirenz (EFV), nevirapine (NVP)
💠high resistance to EFV, NVP
💠low barrier

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Mini-review of three high yield NRTI mutations from rounds today -- Keep scrolling for more! 2/
🧬🧬M184V🧬🧬

💠selected by Emtricitabine (FTC), Lamivudine (3TC)
💠High resistance to: FTC/3TC
⬇️viral fitness
⬆️susceptibility tenofovir (TDF/TAF), zidovudine (AZT)

💠Pt may stay on FTC or 3TC with M184V in order to maintain ⬇️fitness + hypersusceptibility to TAF/TDF