A majority of the available antimicrobial substances contained BDG, potentially limiting the utility of BDG testing in the context of prior exposure to these drugs. As the cumulative effects of repeated BDG exposure are unknown, efforts to reduce contamination should be considered.

1,3-ß-D-glucan (BDG) is increasingly used to diagnose invasive fungal infections (IFI), although false positive results are a concern. To evaluate the potential interaction of blood products with the BDG assay, human albumin (HA), fresh frozen plasma (FFP), undiluted platelet transfusion (UPT) and packed red blood cells (PRBC) were tested for their BDG content using two different b-D-glucan tests. UPTs tested negative, FFP, PBRC and HA tested positive for BDG. In serial dilution, BDG concentration correlated with blood product concentration. To investigate the clinical impact of blood product transfusions, we measured BDG levels before and after the transfusion in three patients (2 PRBC, 1 HA). In the patients receiving PRBC transfusions, BDG values increased from 13 and 17 pg ml(-1) to 183 and 361 pg ml(-1), the HA transfusion increased the serum level from 42 to 58 pg ml(-1). BDG concentrations measured in blood products can be used to predict false positive BDG results.

Objectives We assessed the efficacy and safety of an oral antimicrobial regimen for short- and long-term intestinal eradication of ESBL-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EC/KP) in immunocompromised patients. Methods We performed a randomized (2:1), double-blind multicentre Phase II study in four haematology–oncology departments. Patients colonized with ESBL-EC/KP received a 7 day antimicrobial regimen of oral colistin (2 × 106 IU 4×/day), gentamicin (80 mg 4×/day) and fosfomycin (three administrations of 3 g every 72 h), or placebo. Faecal, throat and urine specimens were collected on day 0, 6 ± 2, 11 ± 2, 28 ± 4 and 42 ± 4 after treatment initiation, and the quantitative burden of ESBL-EC/KP, resistance genes and changes in intestinal microbiota were analysed. Clinicaltrials.gov: NCT01931592. Results As the manufacture of colistin powder was suspended worldwide, the study was terminated prematurely. Overall, 29 (18 verum/11 placebo) out of 47 patients were enrolled. The short-term intestinal eradication was marginal at day 6 (verum group 15/18, 83.3% versus placebo 2/11, 18.2%; relative risk 4.58, 95% CI 1.29–16.33; Fisher’s exact test P = 0.001) and not evident at later timepoints. Quantitative analysis showed a significant decrease of intestinal ESBL-EC/KP burden on day 6. Sustained intestinal eradication (day 28 + 42) was not achieved (verum, 38.9% versus placebo, 27.3%; P = 0.299). In the verum group, mcr-1 genes were detected in two faecal samples collected after treatment. Microbiome analysis showed a significant decrease in alpha diversity and a shift in beta diversity. Conclusions In this prematurely terminated study of a 7 day oral antimicrobial eradication regimen, short-term ESBL-EC/KP suppression was marginal, while an altered intestinal microbiota composition was clearly apparent.

Purpose Residents in nursing homes for the elderly (NH) are at high risk for death from COVID-19. We investigated whether repeated non-mandatory RT-PCR SARS-CoV-2 surveillance of NH staff and visitors reduces COVID-19 incidence rates in NH residents and allows to reduce visiting restrictions. Methods This pilot study at the beginning of the COVID-19 pandemic compared a surveillance approach of regular, twice-weekly voluntary PCR testing of health-care workers (HCW) and visitors in interventional NH (INH) with a setting without regular testing in control NH (CNH). Residents were not tested routinely within this study. Testing was performed in a mobile testing site with same-day result reporting. SARS-CoV-2 incidence among residents in both INH and CNH was the primary endpoint; secondary endpoints being SARS-CoV-2 infection among visitors and HCW in INH. Results Two INH and two CNH participated between October and December, 2020. At INH1, 787 tests of HCW and 350 tests of visitors were performed, accounting for 18.1% (n = 1930) of visits. At INH2, 78 tests of HCW and 372 tests of visitors were done, i.e., 30.5% (n = 1220) of visits. At the two INH 23 HCW and three visitors tested positive for SARS-CoV-2. COVID-19 outbreaks occurred among residents in INH1 (identified through study testing) and in CNH1. Utilization of voluntary testing was low. Conclusion In a real-world setting without available rapid testing, voluntary RT-PCR SARS-CoV-2 testing of HCW and visitors does not prevent COVID-19 outbreaks in NH. Complete, non-selective testing for these groups should be instituted before visiting restrictions can be reduced. Trial registration The study has been registered at ClinicalTrials.gov with the identifier: NCT04933981.