927. Clinical Characteristics and Outcomes of Norovirus Infection in Patients with Hematologic Malignancies: A Retrospective, Single Center Study

Abstract Background Norovirus (NV) gastroenteritis has been identified as a cause of significant morbidity among hematopoietic stem cell transplant (HSCT) recipients, often with associated complications. Current guidelines recommend symptomatic relief with antimotility agents, rehydration, and reduction in immune suppression. Nitazoxanide (NTZ) is an anti-parasitic agent but some literature suggests a benefit of nitazoxanide therapy for NV. Methods We conducted a single center, retrospective chart review study and evaluated adult patients (age >18 years) who had NV infection and either: 1) underwent stem cell transplantation; or 2) received myeloablative chemotherapy within 4 weeks of NV diagnosis by positive test on gastrointestinal pathogen panel during the time period from January 2015 through March 2020. Results 26 patients were reviewed. 14 patients (54%) had a history of HCST prior to infection. Three patients (12%) received both myeloablative chemotherapy and HSCT within four weeks of NV infection. Six patients (46%) had autologous, six (46%) had matched unrelated donor, and one (8%) had haploidentical allogeneic transplants. Nine (69%), three (23%), and one (8%) underwent myeloablative, reduced intensity and non-myeloablative conditioning, respectively. Median duration of diarrhea was 4.5 days (IQR = 2.25-7 days). Three (12%) patients received NTZ or intravenous immune globulin. The 6 month mortality was 42% (11/26), however, none of the deaths were directly attributable to NV infection. Conclusion NV infection led to severe diarrheal disease in our cohort. Overall mortality was high, and a trend toward increased mortality was seen among patients receiving NV-directed therapy; these patients likely received NV-directed therapy due to the severity of their illness. Clinicians must have a high suspicion for this illness and obtain PCR testing for timely diagnosis and management. Table 1. Characteristics of patients with hematologic malignancies and norovirus infection Disclosures All Authors: No reported disclosures

(68%) required hospitalization of which 12 had critical illness. Outcome data was available for 29 individuals of whom 20 (69%) demonstrated improvement. When comparing SOTR with early versus late onset COVID-19 infection in relation to vaccination timing, there were no differences in disease severity (80% vs 75% with severe or critical disease, p=NS) or outcome (30% vs 31% died or deteriorating, p=NS). Background. Norovirus (NV) gastroenteritis has been identified as a cause of significant morbidity among hematopoietic stem cell transplant (HSCT) recipients, often with associated complications. Current guidelines recommend symptomatic relief with antimotility agents, rehydration, and reduction in immune suppression. Nitazoxanide (NTZ) is an anti-parasitic agent but some literature suggests a benefit of nitazoxanide therapy for NV.
Methods. We conducted a single center, retrospective chart review study and evaluated adult patients (age >18 years) who had NV infection and either: 1) underwent stem cell transplantation; or 2) received myeloablative chemotherapy within 4 weeks of NV diagnosis by positive test on gastrointestinal pathogen panel during the time period from January 2015 through March 2020.
Conclusion. NV infection led to severe diarrheal disease in our cohort. Overall mortality was high, and a trend toward increased mortality was seen among patients receiving NV-directed therapy; these patients likely received NV-directed therapy due to the severity of their illness. Clinicians must have a high suspicion for this illness and obtain PCR testing for timely diagnosis and management. Background. Solid organ transplant (SOT) is a growing option for patients with end-stage organ diseases. Immunosuppressive therapy (IT) is utilized in this population to minimize risk of allograft rejection, which increases infection risk particularly of atypical pathogens that can complicate the infection-related diagnostic journey. The purpose of this analysis was to evaluate baseline clinical characteristics and microbiological testing utilization patterns among a cohort of patients with a history of SOT and IT.
Methods. This retrospective cohort study utilized a US hospital-based, service-level database. Patients were selected from a subsample of database facilities utilizing plasma microbial cell-free DNA diagnostic assays. The study period was 1/1/2017-3/21/2020. Eligible patients were identified by 1 st observation of SOT status and IT. Subsequent inpatient admissions for suspected infection were analyzed.
Results. We identified 749 patients with SOT history and use of IT, 56.4% were male, and the mean age was 52.8 (18.7) years. Kidney was the most prevalent transplant category (49.1%), followed by liver (14.1%), lung (10.9%), and heart (10.3%), and 9.7% were multi-organ. Patients experiencing multiple transplants had the most chronic conditions with a mean Elixhauser comorbidity score of 26.3 (14.7). The median length of stay was 4 [3][4][5][6][7] days. The median number of tests per encounter was 6 . Culture was the most utilized test category (2 [1-4]). Blood culture was the highest utilized culture and overall test at 13.5% of all tests observed, while CMV PCR (7.8%) and multi-panel EIA (2.7%) were the most frequent molecular and antigen tests, respectively. Lung transplant recipients had the greatest utilization of tests overall (9 [3.5-17]) versus other transplant categories (6 [3-10]), consistent with the observed test rate in the 1 st 48 hours of presentation (4 [1-7] vs. 2 [1-5]). Background. Nocardia more commonly causes infection in immunocompromised individuals, notably with a relapse rate of approximately 5%. Solid organ transplant recipients will often receive post-treatment prophylaxis as the underlying immunosuppression is unable to be completely removed. However, data supporting this practice is sparse. We sought to evaluate recurrence of nocardiosis in solid organ transplant recipients, specifically evaluating the role of post-treatment prophylaxis.

Conclusion. This analysis suggests that the infection
Methods. We conducted a retrospective cohort study of solid organ transplant (SOT) recipients at our medical center diagnosed with nocardiosis from 2000 through 2020. We included adult SOT recipients who completed their course of Nocardia therapy. Patients were excluded if they had not yet completed therapy, died prior to completing therapy, or there was no post-therapy follow-up. The primary outcome was Nocardia recurrence. Continuous variables were presented as mean or median with interquartile range (IQR).