Fecal Transplant versus Fidoxamicin for Recurrent C Difficile

Fecal transplant (FMT) is increasingly used to treat recurrent clostridium difficile infections (rCDI) with reported cure rates of 70-90%. FMT’s efficacy has been studied in prospective and observation studies, however, it is unclear how it performs against fidoxamicin, a newer antibiotic used in the initial presentation and recurrence of CDI.

FMT is probably more efficacious than fidoxamicin and vancomycin for rCDI. My main concern with this study is that it was unblinded as to who received the FMT and could potentially influence the difference in microbiologic vs symptomatic cures with FMT. Interestingly, more patients treated with antibiotics had microbiologic cures than symptomatic cures, (vancomycin 31% microbiologic cure while only 19% clinical cure).

Fecal Microbiota Transplantation is Superior to Fidaxomicin
for Treatment of Recurrent Clostridium difficile Infection, Gastroenterology (2019)

OPAT for Complicated Staph Infections

Among patients discharged with OPAT for complicated staph infections, 1/3 had an adverse event and nearly 2/3 were re-admitted within 90 days. Patients discharged to a skilled nursing facility (SNF) were lost to follow up at higher rates than those discharged with home care services (HCS) and had higher incidence of line complications. What surprised me was that the ID clinic only received labs from 44% of patients at SNF and 53% at HCS. But at the end of the day, both discharge locations had similar rates of “favorable outcomes”, 61% vs 70%. The SNF vs home care comparison maybe confounded because older and sicker patients are more likely to be sent to SNF/SAR

We often discharge patients on long courses of parenteral antibiotics for Staphyloccus auerus infections and we must recognize they are likely to face significant adverse events and complications. It is unclear if this is due to the severity of the underlying infection, and more importantly, could it have been prevented with closer inpatient monitoring. This study should give you pause when sending patients to SAR/SNF on long term IV antibiotics.

Open Forum Infectious Diseases, Volume 5, Issue 11, 1 November 2018, ofy274

Flea Bytes: HHV-6 Encephalopathy

HHV-6 reactivation is one of the most common causes (in 30-70% of patients) of encephalitis in allo-SCT. It is a ubiquitous viral infection that remains latent and can reactivate after transplant.

Risk factors: HLA mismatch, T-cell depletion therapy, treatment with glucocorticoids, and the use of cord blood as a source of stem cells; 90% of cases of HHV-6 reactivation occur in patients who with cord-blood transplants.

Encephalitis presents as subacute confusion, but some may have a more progressive course. Anterograde amnesia, personality changes, irritability and seizures. SIADH is common.

CSF analysis shows mild lymphocytic pleocytosis and protein elevation.

Treatment is based on in-vitro susceptibility testing and foscarnet is therapy of choice. Can add ganciclovir if not clinically improving. But need to monitor closely for side effects including bone marrow suppression and electrolyte derangement which can predispose to seizures. Alternative therapy is cidofovir, but watch out for nephrotoxicity.  Duration is 3-6 weeks and you shouldn’t monitor PCR levels to shorten treatment duration.

Notes from: N Engl J Med 2018; 378:659-669

Flea Bytes: Treating Aspiration Pneumonia

For most patients: Ampicillin/Sulbactam is sufficient for oral aerobe/anaerobic coverage

For penicillin allergic patients: Clindamycin monotherapy covers oral aerobes/anaerobes

For hospital-acquired aspiration PNA: Coverage of aerobic bacteria, especially GPC and GNR are more important than anaerobes: Pip/Tazo or meropenem monotherapy

In patients with high risk factors for MRSA, can add an agent with MRSA activity but if MRSA is not detected, this agent should be discontinued

Flea Bytes: Polymixin/Meropenem Synergy

Meta-analysis found in vitro synergy.  Especially in A baumanii. Mechanism unclear

Synergy testing can be done on isolate if available

Can not necessarily infer in vivo synergy (Beta-lactam/aminoglycoside synergy is demonstrated in vitro but NOT in vivo for example).

Systematic Review and Meta-Analysis of In Vitro Synergy of Polymyxins and Carbapenems. Antimicrobial Agents and Chemotherapy. October 2013 Volume 57 Number 10. p.5104 – 5111.

Tidings from the Citadel: Accuracy of Lung Ultrasonography in the Diagnosis of Pneumonia

16 studies were included – significant heterogeneity, but of 2359 patients. Heterogeneity was assessed graphically and with a Q test. The Q test should only be used once in a data set to exclude outliers. The reference standard, we considered it to be of high quality if based on CT alone or when it consisted of a final diagnosis made by experts using an integrated synthesis of radiology and laboratory or microbiological data (or both).

The highest risk of bias stemmed from the flow of patients within each study because of an uneven application of the reference test (differential verification bias).

The dispersion of studies in the ROC plane suggests marked heterogeneity.
The 95% CI of the overall effect indicates a sensitivity of approximately 80% to 90% and a specificity of 70% to 90%.

References:
Accuracy of Lung Ultrasonography in the Diagnosis of Pneumonia in Adults: Systematic Review and Meta-Analysis – Ana M. Llamas-Álvarez, MD; Eva M. Tenza-Lozano, MD; and Jaime Latour-Pérez, MD, PhD; . Chest 2017; 151(2):374-382

Flea Bytes: Antibiotics or Surgery for Spinal Epidural Abscess

Baseline rates of treatment failure have varied in studies and rates have ranged from 8.5 to 17% in the best case scenarios to 43-75% in other studies. So even at baseline, we know that a significant number of patients will fail antibiotics and require surgery. Risk factors include diabetes mellitus, leukocytosis greater than 12.5, positive blood cultures, and C-reactive protein greater than 115. One risk factor increases failure rates for to 35.4%, two risk factors increases failure to 40.2%, and three or more risk factors increases failure rates to 76.9%.

So basically, most patients should ideally managed with surgery and barring that we should advocate for surgery in patients who have risk factors.