Predicting overall viability of cord blood harvests

BACKGROUND: Cord blood (CB) is a product rich in primitive adult stem cells used in hematopoietic stem cell transplantation. After collection, the CB is transported to a facility where the unit is processed and then frozen up to 48 hours later. These processes can lead to compromised white blood cell (WBC) viability. This study investigates the factors that affect WBC viability before freezing of the cells. STUDY DESIGN AND METHODS: We retrospectively analyzed WBC viability from 9918 CB collections harvested from 2003 to 2010 to determine if collection volume and time to freezing (TTF) had a significant effect on WBC viability. CB was collected in dispersed clinical locations by local staff trained to the same methods. CB was transported to the central lab under controlled conditions for analysis and processing. RESULTS: The collected CB units had a mean volume of 77.1 ± 31.3 mL, mean WBC count of 10.5 × 10⁸ ± 5.6 × 10⁸, mean total CD34+ cell count of 4.0 × 106 ± 3.7 × 106, and mean WBC viability of 91.7% ± 6.5%. WBC viability was most significantly affected by the volume of CB collected and the TTF. As collection volumes increased, WBC viability increased, with mean viability of 95.0% ± 3.5% in CB collections of more than 120 mL. Decreased viability was associated with volumes of less than 60 mL and TTF of more than 24 hours. From these data we have developed decision tables that estimate WBC viability based on CB volume and TTF. CONCLUSION: This study identifies optimal TTF for different collection volumes to maintain WBC viability of the collected CB.7 page(s

Epidemiological and Genomic analysis of a Sydney Hospital COVID-19 Outbreak

Abstract Australia’s early COVID-19 experience involved clusters in northern Sydney, including hospital and aged-care facility (ACF) outbreaks. We explore transmission dynamics, drivers and outcomes of a metropolitan hospital COVID-19 outbreak that occurred in the context of established local community transmission. A retrospective cohort analysis is presented, with integration of viral genome sequencing, clinical and epidemiological data. We demonstrate using genomic epidemiology that the hospital outbreak (n=23) was linked to a concurrent outbreak at a local aged care facility, but was phylogenetically distinct from other community clusters. Thirty day survival was 50% for hospitalised patients (an elderly cohort with significant comorbidities) and 100% for staff. Staff who acquired infection were unable to attend work for a median of 26.5 days (range 14-191); an additional 140 staff were furloughed for quarantine. Transmission from index cases showed a wide dispersion (mean 3.5 persons infected for every patient case and 0.6 persons infected for every staff case). One patient, who received regular nebulised medication prior to their diagnosis being known, acted as an apparent superspreader. No secondary transmissions occurred from isolated cases or contacts who were quarantined prior to becoming infectious. This analysis elaborates the wide-ranging impacts on patients and staff of nosocomial COVID-19 transmission and highlights the utility of genomic analysis as an adjunct to traditional epidemiological investigations. Delayed case recognition resulted in nosocomial transmission but once recognised, prompt action by the outbreak management team and isolation with contact and droplet (without airborne) precautions were sufficient to prevent transmission within this cohort. Our findings support current PPE recommendations in Australia but demonstrate the risk of administering nebulised medications when COVID-19 is circulating locally

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017–2020Research in context

Summary: Background: New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice. Methods: The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017–December 2020). Descriptive analyses were used to report patients’ demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM). Findings: Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria – 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51–69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04–3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93–8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88–2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15–13.44, p = 0.028). Interpretation: IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes. Funding: This work is unfunded. All authors’ financial disclosures are listed in detail at the end of the manuscript