Norovirus is an emerging pathogen causing gastroenteritis. We sought to identify factors associated with clinical outcomes in a cohort of patients with laboratory-confirmed norovirus infection. We ...performed a retrospective chart review of patients with positive norovirus polymerase chain reaction in stool between October 1, 2015, and May 31, 2016. 128 unique patients were identified during the study period, 64 of whom had immune deficiency, of which only 3 patients had a primary immune deficiency (common variable immune deficiency), while 61 patients had a secondary immune deficiency. 50% of patients with immune deficiency were hospitalized as compared to only 30% of the non–immune-deficient cohort (odds ratio: 2.1 (1.1–4.18, P=0.04). One-third (32.8%) of the patients had a polymicrobial stool infection, and 21.1% had concurrent Clostridium difficile infection. Initial mean total leukocyte count was higher in the hospitalized group at 8.40×109/L versus 6.31×109/L in the nonhospitalized group (P=0.049). All 13 patients presenting with fever had symptomatic resolution (P=0.002). The presence of C. difficile infection was correlated with persistent symptoms (OR 2.30 0.95–5.58, P=0.067). The overall mortality rate among our cohort was 3.13% (4 patients). All deceased patients had secondary immune deficiency, and none had C. difficile coinfection. Presence of an immune deficiency increases the risk of hospitalization with norovirus infection. Absence of fever is associated with lower resolution and possibly may contribute to a persistent infectious state. Presence of concomitant C. difficile infection is correlated with a lower overall mortality rate.
Abstract
Background
Accurate diagnosis of rCDI is challenging because of limitations in test performance and alternative causes of recurrent diarrhea, such as post-infectious irritable bowel syndrome ...(IBS). Stool enzyme immunoassay (EIA) toxin testing (TOX) is the best predictor of active disease, but may miss cases of CDI when toxins are below the limit of detection. In contrast, glutamate dehydrogenase (GDH) or PCR have high sensitivity but cannot differentiate colonization from infection, leading to possible overdiagnosis due to low specificity. In ECOSPOR III, SER-109, an investigational purified microbiome therapeutic, was superior to placebo in reducing rCDI (12.4% vs 39.8%, respectively; p-value < 0.001). We examined diagnostic testing patterns among screened subjects.
Methods
Patients with ≥2 prior episodes and ≥3 unformed bowel movements over 48 hours were screened. To ensure enrollment of patients with active CDI, toxin testing was required at entry via a local certified or central lab (Eurofins; Framingham, MA). Subjects with discordant GDH+/TOX- tests at the central lab had reflex confirmatory testing with a cell cytotoxicity neutralization assay (CCNA), considered the “gold standard” for toxin testing.
Results
The leading reason for screen failure among 281 subjects screened was a negative toxin test (50/99; 50.5%). Of 182 patients enrolled, 59 (32.4%) qualified with EIA TOX+ at the local lab (33 TOX+; 25 GDH+/TOX+) and 122 (67.0%) qualified by the central lab (Table 1). Of these 122 subjects, 87 qualified by GDH+/TOX+ but 35 required additional reflex testing by CCNA due to discordant GDH+/TOX-results; all 35 were positive.
Diagnostic Testing for Qualifying C. difficile Episode in ITT Population
Conclusion
These diagnostic testing patterns suggest a subset of patients with suspected rCDI have toxin concentrations below the EIA threshold for detection or may have an alternative cause of diarrhea, such as post-infectious IBS. Thus, the limitations of EIA toxin testing need to be considered in clinical practice when evaluating patients with compatible symptoms of rCDI and a high prior probability of infection. In contrast, in trials of investigational agents, toxin testing assures enrollment of patients with active disease and accurate estimates of efficacy.
Disclosures
Matthew Sims, MD, PhD, FACP, FIDSA, Astra Zeneca (Independent Contractor)Diasorin Molecular (Independent Contractor)Epigenomics Inc (Independent Contractor)Finch (Independent Contractor)Genentech (Independent Contractor)Janssen Pharmaceuticals NV (Independent Contractor)Kinevant Sciences gmBH (Independent Contractor)Leonard-Meron Biosciences (Independent Contractor)Merck and Co (Independent Contractor)OpGen (Independent Contractor)Prenosis (Independent Contractor)Regeneron Pharmaceuticals Inc (Independent Contractor)Seres Therapeutics Inc (Independent Contractor)Shire (Independent Contractor)Summit Therapeutics (Independent Contractor) Sahil Khanna, MBBS, MS, Seres (Grant/Research Support) Darrell Pardi, MD, seres (Consultant)Vedanta (Consultant) Paul Feuerstadt, MD, FACG, Ferring/Rebiotix Pharmaceuticals (Consultant, Scientific Research Study Investigator, Speaker's Bureau)Finch Pharmaceuticals (Scientific Research Study Investigator)Merck and Co (Speaker's Bureau)SERES Therapeutics (Consultant, Scientific Research Study Investigator)Takeda Pharmaceuticals (Consultant) Elaine E. Wang, MD, Seres Therapeutics (Employee) Elaine E. Wang, MD, Seres Therapeutics (Employee, Shareholder) Barbara McGovern, MD, Seres Therapeutics (Employee, Shareholder) Lisa von Moltke, MD, Seres Therapeutics (Employee, Shareholder)
Abstract
Background
Treatment for first recurrent Clostridioides difficile infection (frCDI) or multiply recurrent CDI (mrCDI) is complex and may include antibiotics, monoclonal antibodies, or fecal ...transplantation. Improved understanding of rCDI pathogenesis can help guide treatment. We report microbiome findings of patients (pts) with frCDI and mrCDI from a post hoc analysis of two phase 3 trials with fecal microbiota spores, live-brpk (FMS; formerly SER-109), an FDA-approved, microbiota-based therapeutic comprised of Firmicutes spores.
Methods
Stool samples were collected from pts with mrCDI in ECOSPOR III (n=158) and with frCDI or mrCDI in ECOSPOR IV (n=218) at baseline (pre-dose) and Week 1 post treatment. Shannon diversity was calculated from species profiles from analysis of whole metagenomic sequencing data using MetaPhlAn2. Primary (1°BA) and secondary bile acid (2°BA) concentrations were measured via targeted liquid chromatography–mass spectrometry panel. Subgroup differences were analyzed with linear mixed models.
Results
At baseline, Shannon diversity was not significantly different between mrCDI and frCDI groups (P>0.05). At Week 1, Shannon diversity (Fig 1) was greater vs baseline (P< 0.001); gains were not significantly different between subgroups (P>0.05). For pts receiving FMS vs placebo in ECOSPOR III, greater reductions in 1°BA and increases in 2°BA from baseline–Week 1 were observed, similar to FMS-treated pts in ECOSPOR IV. At Week 1, 2°BA concentrations were greater vs baseline (P< 0.001); similar gains were seen between subgroups (P>0.05) (Fig 2). Consistent with these microbiome findings, in an integrated analysis, rCDI rates with FMS at Week 8 were low in both subgroups (frCDI, 6.5% 5/77 vs mrCDI, 10.3% 28/271).
Conclusion
After antibiotics, pts with frCDI or mrCDI had low Shannon diversity and 2°BA concentrations that were no different between subgroups, highlighting a need for microbiome restoration. Both subgroups showed rapid, significant improvement in Shannon diversity and 2°BA concentrations and reductions in 1°BA after FMS, with comparable clinical outcomes. These data suggest that regardless of number of prior CDI episodes, FMS therapy following antibiotics may be an optimal treatment.
Disclosures
Colleen R. Kelly, MD, Openbiome: Advisor/Consultant|Sebela Pharmaceuticald: Advisor/Consultant Tim Straub, MS, Seres Therapeutics: Employee|Seres Therapeutics: Stocks/Bonds Kevin Litcofsky, PhD, Seres Therapeutics: inventor on patents assigned to Seres Therapeutics|Seres Therapeutics: Employment|Seres Therapeutics: Stocks/Bonds Jennifer R. Wortman, MS, Seres Therapeutics: Employee|Seres Therapeutics: Stocks/Bonds Barbara McGovern, MD, Seres Therapeutics: Stocks/Bonds Brooke Hasson, PhD, Sage Therapeutics: Stocks/Bonds|Seres Therapeutics: Stocks/Bonds Dina Hot, PhD, Aimmune Therapeutics: Employee Darrell Pardi, MD, Abbvie: Advisor/Consultant|AMT: Grant/Research Support|BI: Advisor/Consultant|Immunic: Advisor/Consultant|Rise: Advisor/Consultant|Seres Therapeutics: Advisor/Consultant|Seres Therapeutics: Grant/Research Support|Summit: Advisor/Consultant|Takeda: Grant/Research Support|Vedanta: Advisor/Consultant|Vedanta: Grant/Research Support Christopher Ford, PhD, Seres Therapeutics: Employee|Seres Therapeutics: Stocks/Bonds Matthew Henn, PhD, Seres Therapeutics: Employee|Seres Therapeutics: Stocks/Bonds
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