Module 4: Management of GI infections

What is the leading cause of infectious diarrhea?

Virus: Noroviruses (Dr. Karst’s lab)

what is the difference b/w inflammatory vs watery diarrhea?

* inflammatory: due to mucosal invasion by BACTERIA
* bloody diarrhea and fever
* Common causes: CHEESY pathogen
* watery: toxins lead to decreased absorption of water
* dehydration and electrolyte imbalance
* Common cause: virus, vibrio cholera, enterotoxigenic E.coli

what CHEESY pathogen include?

* CHEESY pathogen:
* Campylobacter, Hemorrhagic E. coli, Enteroinvasive E. coli
* Salmonella, Shigella, Yersinia

which population are recommended to get blood culture?

1. infants < 3mo
2. anyone with systemic manifestations


1. immunocompromised

what we should do if diarrhea lasts > 14 days?

conduct parasitic studies

what pathogens need **specialized** stool test?

STEC

C. diff

what are the goals of rehydration therapy?

resolve fluid losses

correct electrolyte imbalances

correct metabolic acidosis

should breastfeeding continue for infants?

No

what food we should avoid with rehydration?

foods high in fiber, salt, sugar, which can create more fluid loss

→ lead to osmotic diarrhea

what is the dosage of ORT?

adults: 50-100 mL/kg over first 3-4hrs

* ongoing losses: can continue in a smaller amount

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what are the benefits of using Abx for diarrhea in infection?

shorten duration of sx. lessen severity of sx, shorten duration of fecal shedding

who we should give Abx?

* infants < 3mo
* International travelers with bloody diarrhea + fever, and/or signs of sepsis
* immunocompromised with severe illness and bloody diarrhea

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what is the 1st line Abx for adults and children?

Azithromycin (same for moderate and severe TD )

* 3rd gen cep (for

when we should avoid to give anti-motility agents for sx relief?

when the infection is toxin-mediated

* avoid if bloody diarrhea or high fever is present

Generally not recommended in children

who and how should we administer Zn

Children 6mo-5 years with malnutrition in developing countries

20mg/day for 1-2 weeks

ADE: metallic taste, vomitting

what is the main cause for TD Infection?

bacteria, accounting for 80-90% of cases

What is the Abx of choice for TD prophylaxis?

Rifaximin

* only for immunocom. and unavoidable trips

can use BSS as an alternative (AE: blackening of the tongue and stool)

which of the following is NOT Risk factor for C.dif

* Age greater than 65 yo
* Chemo or immunosuppression
* Severe morbidity
* GI surgery
* PPI: especially long-term use
* **No history of Abx use**

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What 2 meds that have highest risk of CDI

Clindamycin

FQ

which dx tests are commonly used for CDI?

* GDH
* EIA Toxin A and B

Dosage of Metro in CDI trx

500mg PO/IV q8hr

Systemically absorbed

High collateral damage

IV for severe infection

is Vanco PO and Fidaxomicin Systemically absorbed?

No

How frequent vanco is used in CDI?

q6h

125mg PO q6h (NOT IV)

vs Fidaxomicin 200mg PO **q12hr**

what is the advantage of using Fidaxomicin over Vanco in CDI?

less recurrence b.c of having narrower spectrum

* BUT MUCH MORE expensive
* difference NOT maintained for pts with BI/NAP1/027 strains

what is the level of WBC and SCr in severe CDI?

* WBC: > 15k
* SrCr > 1.5mg/dL

How long do we treat CDI?

10 days

How differently fulminant CDI is treated than mild/moderate or severe stage?

* Metronidazole IV is used along with Van 500 mg (NOT 125mg) PO
* Both are 500 mg

what is the preferred option for CDI recurrence?

Fidaxomicin 200 mg PO BID for 10 days

What is NOT exclusion criteria for FTM donor?

Abx in last 6 mo

* should be last 3 mos

What is Rebyota?

Fecal microbiota suspension for rectal administration

* apply rectally AFTER completion of CDI Abx (usually after 2-3 days) for pt who have at least 1 recurrence

what is MOA of Bezlotoxumab?

binds to toxin B and neutralizes it

* need to give WITH Abx

which populations should we give Bezlotoxumab?

Second CDI in 6 mo

The elderly

Immunocom.

Severe CDI

In which condition probiotics are proved to be effective?

Abx- associated diarrhea

What Kefir contains and when it should be used?

* Include: fermented milk, yeast, probiotics
* Indication: in recurrent CDI, given with staggered, taperd metro, vanco regimen (for 8 weeks)
* inconclusive result